what is sleep apnea? · what is sleep apnea? description sleep apnea is a serious, potentially...

WHAT IS SLEEP APNEA? .......................................................................... 3

DESCRIPTION...................................................................................................................................................................3RESEARCH ........................................................................................................................................................................3

How common is Sleep Apnea? .......................................................................................................................3Life Style Impact ..................................................................................................................................................4Medical Impact ......................................................................................................................................................4Sleep Test ................................................................................................................................................................4Treatment ................................................................................................................................................................5

T ERMS ...............................................................................................................................................................................7 A ...................................................................................................................................................................................7B ...................................................................................................................................................................................8C ...................................................................................................................................................................................9D .................................................................................................................................................................................10E .................................................................................................................................................................................11F .................................................................................................................................................................................12G .................................................................................................................................................................................12H .................................................................................................................................................................................13I ...................................................................................................................................................................................13J ..................................................................................................................................................................................14K .................................................................................................................................................................................14L ..................................................................................................................................................................................14M .................................................................................................................................................................................15N .................................................................................................................................................................................15O .................................................................................................................................................................................16P .................................................................................................................................................................................17Q .................................................................................................................................................................................19R .................................................................................................................................................................................19S ..................................................................................................................................................................................20T ..................................................................................................................................................................................24W .................................................................................................................................................................................26Z ..................................................................................................................................................................................26

SLEEP LINKS ..................................................................................................................................................................26

APLAB: WHAT IS IT?.............................................................................. 27

HOW DOES IT WORK?...................................................................................................................................................27Simple explanation ............................................................................................................................................27Clinical explanation:..........................................................................................................................................28

FEATURES .......................................................................................................................................................................29BENEFITS........................................................................................................................................................................29QUALITY ASSURANCE ...................................................................................................................................................29APLAB HISTORY ............................................................................................................................................................29CLINICAL STUDIES........................................................................................................................................................30

Study #1 ................................................................................................................................................................30Study # 2 ...............................................................................................................................................................33Study # 3 ...............................................................................................................................................................33

SLEEP APNEA BACKGROUND .......................................................................................................................................35REFERENCES .............................................................................................................................................................37INTERPRETING APLAB™ NASAL PRESSURE WAVEFORMS......................................................................................42SLEEP APNEA EXAMPLE SCREEN SHOTS ...................................................................................................................43ARTICLES........................................................................................................................................................................48

Links .........................................................................................................................................................................48ARTICLES: TABLE OF CONTENTS................................................................................................................................50ARTICLES........................................................................................................................................................................52

FAQ’S .................................................................................................... 71

WHAT CAUSES SLEEP APNEA? ...................................................................................................................................71

WHO GETS SLEEP APNEA?..........................................................................................................................................72HOW IS NORMAL BREATHING RESTORED DURING SLEEP? ...................................................................................72WHEN SHOULD SLEEP APNEA BE SUSPECTED? .......................................................................................................72ABOUT INSURANCE .......................................................................................................................................................73

CONTACT US.......................................................................................... 73

E-MAIL ............................................................................................................................................................................73PHONE.............................................................................................................................................................................73ADDRESS ........................................................................................................................................................................73

PARTNER LINKS .................................................................................... 73

What is Sleep Apnea?

DescriptionSleep apnea is a serious, potentially life-threatening condition defined asinterruptions of breathing during sleep.

There are two types of sleep apnea: 1) central and 2) obstructive.

Central sleep apnea, which is less common, occurs when the brainfails to send the appropriate signals to the breathing muscles toinitiate respirations.

Obstructive sleep apnea is much more common and occurs when air cannotflow into or out of the person’s nose or mouth although efforts to breathecontinue.

During sleep, the body's muscles relax, which can cause excess tissueto collapse into the upper airway (back of the mouth, nose and throat)and block breathing.

When breathing is interrupted by an obstruction in the airway, thebody reacts by:

Waking enough to start breathing again. These arousals may occur hundreds of times each night but do not

fully awaken the patient, who remains unaware of the loud snoring,choking and gasping for air that are typically associated withobstructive sleep apnea.

Obstructive sleep apnea sufferers never get "a good night's sleep"because repeated apneas deprive patients of deep-stage sleep,leading to chronic daytime exhaustion and long-term cardiovascularstress.

Research

How common is Sleep Apnea?

According to the National Institutes of Health, sleep apnea is verycommon, as common as adult diabetes, and affects more than 20million Americans. The 1993 report of the National Commission onSleep Disorders Research estimated that 38,000 cardiovasculardeaths each year are associated with sleep apnea. Moreover, sleepapnea may be responsible for job impairment and motor vehiclecrashes.

Life Style ImpactThe consequences of sleep apnea range from annoying to lifethreatening. They include symptoms suggesting:

Depression Irritability Sexual dysfunction Learning and memory difficulties Falling asleep during the day (while working, watching TV, driving,etc) 3 times (or more) likely to have automobile accidents; High blood pressure Irregular heart beat Higher risk for heart attack an

Medical ImpactUntreated, sleep apnea can cause:

High blood pressure Irregular heart beat Cardiovascular disease Memory problems Weight gain Impotency Headaches Death

Sleep Test

The Epworth Test as used by most Sleep Clinics.How likely are you to doze off or fall asleep in the following situations incontrast to just feeling tired? This refers to your usual way of life in recenttimes.

Use the following scale to choose the most appropriate number, for eachsituation.

0 = No chance of dozing1 = Slight chance of dozing2 = Moderate chance of dozing3 = High chance of dozing

Sitting and Reading

0-None

Watching TV

0-None

Sitting inactive in a public place (e.g. a theater or a meeting)

0-None

As a passenger in a car for an hour without a break

0-None

Lying down to rest in the afternoon when circumstances permit

0-None

Sitting and talking to someone

0-None

Sitting quietly after lunch without alcohol

0-None

In a car, while stopped for a few minutes in traffic

0-None

Select a value (0 - 3) from each box. When you've completed yourselections, read the results of your score.

If your score is greater than 6 points, then you are sleepy. If yourscore is 10 or more points, you are very sleepy. If your score is morethan 16 points you are dangerously sleepy.

Test result notesThis test does not prove or disprove that you have sleep apnea.Many other things could contribute to excessive sleepiness. It isjust an indication of whether further investigation is needed.

Please Note: Information on this website is not medicaladvice. Always seek the advice of your doctor if you have ahealth problem.

Treatment

Mild Sleep ApneaIf you have mild sleep apnea, the doctor may suggest:

Weight loss No alcohol No caffeine No sleeping pills In some people the apneas only occur while lying on their back.Pillows or any object that keeps you on your side can be helpful.

Moderate to Severe Sleep Apnea

CPAP- Continuous Positive Airway PressureA CPAP machine supplies airflow to the nose and/or mouth to keep theairway open throughout the night. The pressure varies according to howsevere the sleep apnea is and how much pressure is needed to preventcollapse.

A CPAP mask is held in place by a headgear and tubing that goes from themask to the CPAP unit. The CPAP unit is plugged into an electrical outlet andprovides a constant flow of air to the mask.

Dental DevicesYour doctor may prescribe a dental device if you have mild sleep apnea oryou are unable to use a CPAP. The dental device is molded by the dentistand placed in the mouth for use at night to hold the lower jaw and tongueforward.

This device is available in either a fixed type or an adjustable type. Theadjustable type has a higher success rate than the fixed type. Adjustmentsare made over a period of time to gradually move the lower jaw forwardwhile using the dental device.

If you want more information on dental appliances, talk to your sleep doctorfor a referral to a dentist in your area with special training in dentalappliances for sleep apnea. After you have the appliance you may need asleep test to find out if the appliance helps you.

Radio Frequency ProcedureRadio waves are used to shrink the tissue in the throat or tongue makingmore space in the throat. The tongue, throat, or soft palate is pierced witha special needle (electrode) connected to a radio frequency generator. Theinner tissue is heated to 158-176 degrees Fahrenheit, which takes about 30minutes. The inner tissue shrinks while the outer tissue stays the same.Several treatments are needed to complete the process.

This is a new treatment and not available in all areas. The success ratefor treating sleep apnea is vague because the procedure is fairly new.

Surgery for Sleep Apnea

Some newer surgery is available in larger centers where the doctorsspecialize in reconstructive surgery for sleep apnea. The surgery ispermanent so you want the best possible outcome for your situation.Before you consider surgery, talk to your doctor to see if it would helpyou and ask for a referral to a specialized center.

Each individual has a different shaped nose and throat so before surgery isconsidered the person has an office visit with the specialist to measurethe airway at several points and is examined to check for any abnormalflow of air from nose to lungs.

The surgeon may try other treatments before surgery to see if they workbefore deciding that surgery is the best option for you.

Types of surgery are:

Conventional or regular surgery - Performed by a surgeon, usually in anoperating room of a hospital or clinic. The surgeon uses generalanesthetic or local freezing to control any pain for the patient. There maybe some pain after the surgery which can be controlled by medication.

UPPP (Uvulopalatopharyngoplast) - A surgeon cuts away the uvula andpart of the soft tissue at the back of the throat. This may change orreduce loud snoring but has limited success in treating sleep apnea.Sometimes with sleep apnea the throat is blocked by the tongue furtherdown the airway.

Laser surgery - this procedure can be done in the doctor's office buttakes between one and seven visits to complete. There is some pain andswelling after the laser surgery that usually goes away in a few days. Asleep test (polysomnography) is needed after surgery to see if the sleepapnea is reduced. Laser is used to remove the uvula and soft tissue atthe back of the throat. Check with your medical policy coverage to see ifthis type of surgery is included.

Terms

A

Abdominal Movement - In diagnostic sleep studies, abdominalmovement is recorded. This is one of the measures ofrespiratory effort, reflecting movement of the diaphragm.Advanced Sleep Phase Syndrome (ASPS) - Phases of thedaily sleep/wake cycle are advanced with respect to clocktime. This is classified as a circadian rhythm disorder. Thesleep phase occurs well ahead of the conventional bedtime andthe tendency is to wake up too early.Alpha rhythm - EEG oscillations, prominent over the occipitalcortex, with a frequency of 8-13 Hz in adults; indicative of theawake state; present in most, but not all, normal individuals;most consistent and predominant during relaxed wakefulness.

Alpha intrusion - brief occurrence of alpha activity during a stage ofsleep.Ambulatory Monitor - Portable system used to record (continuously)multiple physiological variables during sleep.Apnea - Literally means "no breath"; the cessation of airflow atthe nostrils and mouth for at least 10 seconds.Apnea index (AI) - A measure of the severity of sleep apnea;the number of apnea events per hour.Apnea/Hypopnea index (AHI) - the number of apneas andhypopneas per hour. 5-20=mild, 21 -50=moderate, above 51severeArousal - abrupt change from sleep to wakefulness, or from a"deeper" stage of non-REM sleep to a "lighter" stageArousal Disorder - parasomnia disorder presumed to be due toan abnormal arousal function. Classical arousal disorders:sleepwalking, sleep terrors and confusional arousals.Arousal Threshold - ease that a sleeping person is awakened.Arrhythmia - irregularity or absence of the heart rhythmcaused by disturbances in transmission of electricalimpulses through cardiac tissue.Auto Adjusting Continuous Positive Airway Pressure Device(Smart PAP) (Auto-PAP) - A type of CPAP machine monitoringchanges in breathing and compensates automatically by makingappropriate adjustments in pressure.Automatism - automatic action--especially any action performedapparently without intention or awareness.

B

Basic Sleep Cycle –a progression through orderly succession ofsleep states and stages. For the healthy adult, the first cycle isbegins by going from wakefulness to non-REM sleep. The first REMperiod follows the first period of non-REM sleep, and the two sleepstates continue to alternate throughout the night with an averageperiod of about 90 minutes. A night of normal human sleepusually consists of 4-6 non-REM/REM sleep cycles.Benzodiazepines - developed in the 1950's, this class of compoundstranquilizes and sedates.Beta Activity - brain waves with a frequency of greater than 13 Hz(Hertz).Bi-Level - Bi-level pressure device used to treat sleep apnea.The "bi" refers to two pressures: a lower pressure for exhalationand a higher pressure for inhalation. Bi-Level machines aremore expensive than a standard CPAP, but some patientstolerate it better because they can exhale comfortably againstthe constant inhalation pressure. (Sometimes called Bi-PAP, but

that is a trademark name of one system)Biological Clock – a term for the brain process causing us to have24-hour fluctuations in body temperature, hormone secretion, andother bodily activities. The most important function fosters thedaily alternation of sleep and wakefulness. The biological clock isfound in a pair of tiny bilateral brain areas called thesuprachiasmatic nuclei.Body Position - four positions are identified which a patient maybe sleeping; back, left side, right side or abdomen. The time spentsleeping in each position and the number of respiratory events in aparticular position is tabulated.BIPAP = Bi-level Positive Airway Pressure. Used to treat sleep apnea, itis the same as CPAP, except the pressure of the airflow dropssignificantly when you expire; there is no need to fight the incoming airpressure. The bipap can be set to drop the level at specific intervals, orupon demand.Bradycardia - heart rhythm with a rate lower than 60 beats per minutein an adult.Brain Waves – the brain’s spontaneous electrical activity studiedby electroencephalography (EEG).Bruxism – teeth grinding during sleep

C

Cardiac Arrest - sudden cessation of the heart beat.Cardiovascular - Pertaining to blood vessels and the heartCataplexy - sudden, dramatic decrement in muscle tone and lossof deep reflexes that leads to muscle weakness, paralysis, orpostural collapse. Usually caused by outburst of emotion:laughter, startle, or sudden physical exercise; one of the tetrad ofsymptoms of narcolepsy.Central apnea - absence of airflow and inspiratory effort; apneacaused by irregularity in the brain's control of breathing.Central Nervous System (CNS) - brain and spinal cord.Cheyne-Stokes respiration - breathing pattern typified byregular "crescendo-decrescendo" or waxing and waningfluctuations in respiratory rate and tidal volume.Chronic Fatigue Syndrome = Chronic fatigue syndrome ischaracterized primarily by profound fatigue. There is usually an abruptonset of symptoms that come and go for at least six months.Chronotherapy - treatment for circadian rhythm sleepdisorder by systemically changing sleeping and waking times toreset the biological clock.Circadian rhythm - innate, daily, fluctuation of behavioral andphysiological functions, including sleep waking, generally tiedto the 24 hour day-night cycle but sometimes to a different

(e.g., 23 or 25 hour) periodicity when light/dark and other timecues are removed.Compliance - adhering to or conforming with a regimen of treatmentsuch as CPAPCPAP - Continuous Positive Airway Pressure; the device used totreat sleep apnea by sending positive airway pressure at aconstant, continuous pressure to help keep an open airway,allowing the patient to breathe normally through his/her noseand airwayCPAP Pressure - pressure needed to maintain an open airwayin a sleep apnea patient treated with CPAP, expressed incentimeters of water (cm H20). The positive pressure can rangefrom 5 - 20 cm H20. Different patients require differentpressures. The value is determined in a CPAP titration study.

D

Deep Sleep - refers to combined non-REM sleep stages 3 and 4 insleep studiesDelayed sleep phase - A condition occurring when the clock hourat which sleep normally occurs is moved back in time in a given,24 hour sleep-wake cycle. The result is a temporarily displaced(delayed) occurrence of sleep within the 24 hour cycle.Delta sleep - stage(s) of sleep in which EEG delta waves areprevalent or predominant (sleep stages 3 and 4, respectively).Delta waves - EEG activity with a frequency less than 4 Hz. In humansleep stage scoring; conventionally the minimum criteria for scoringdelta waves are 75 uV (peak-to-peak) amplitude, and 0.5 secondduration (2 Hz).Diagnostic Sleep Study - monitoring of several physiologicalactivities in a sleeping individual. Usually performed to determinethe absence or presence of a specific sleep disorder. The sleep studycan occur in a sleep disorders center or in a patient's home withportable recording equipment.Diaphragm - large, concave muscle attached to the rib cage at bottomof the chest (top of the abdomen). Inhalation occurs when diaphragmcontracts. Exhalation is passive as the muscle relaxes.Diurnal - active and wakeful in the daytime versus active in thenighttimeDME - Durable Medical Equipment. Equipment such as wheelchairs andwalkers which are prescribed for use by or on the order of a physician,also includes CPAP and BI-Level machines.Drowsiness, Drowsy - quiet wakefulness occurring prior to sleeponset.Dyssomnia - a disorder of sleep or wakefulness; not a parasomnia

E

Electrocardiography (EKG) – a method of measuring the electricalactivity of the heart.Electrodes - small devices transmitting biological electrical activityfrom subject to polygraphElectroencephalogram (EEG) - recording through the scalp ofelectrical potentials from the brain and the changes in these potentials.The EEG is one of the three basic variables (along with the EOG & EMG)used to score sleep stages and waking. Surface electrodes are used torecord sleep in humans, recording potential differences between brainregions and a neutral reference point, or between brain regions.Electromyogram (EMG) - recording of electrical activity from themuscular system; in sleep recording, synonymous with resting muscleactivity or potential. The chin EMG, along with EEG and EOG, is one ofthe three basic variables used to score sleep stages and waking.Surface electrodes are used to record sleep in humans, measuringactivity from the submental or masseter muscles. These reflect thechanges in resting muscle activity. During REM sleep the chin/cheekEMG is tonically inhibited.Electro-oculogram (EOG) - recording of voltage changes resultingfrom shifts in position of the eyeball-possible because each globe is apositive (anterior) and negative (posterior) dipole; along with the EEGand the EMG, one of the three basic variables used to score sleep stagesand waking. Human sleep recordings utilize surface electrodes placednear the eyes to record the movement of the eyeballs. Rapid eyemovements in sleep indicate a certain stage of sleep ( usually REMsleep).ENT - Ear, Nose and Throat. A doctor specializing in diseases of theEar, Nose and Throat. These specialists often do surgery as well, andmay be referred to as an ENT surgeon.EPAP - Expiratory Positive Airway Pressure. Pressure prescribed for theexpiratory (breathing out) phase of an individual on Bi-level CPAPtherapy for OSA (obstructive sleep apnea).Epidemiology - Scientific discipline studying the incidence,distribution, and control of disease in a population. Includes the studyof factors affecting the progress of an illness, and, in the case of manychronic diseases, their natural history.Epoch - A standard 30 second duration of the sleep recording that isassigned a sleep stage designation; for special purposes, occasionallylonger or shorter epochs are scored.Epworth Sleepiness Scale - index of sleep propensity during theday as perceived by patients, and derived from the answers to 8questions.Esophageal Pressure - measurement used to determine respiratoryeffort and by inference, airway resistance. Considered an invasive

measure, generally used only in polysomnography testing, conducted insleep disorders centers.Excessive daytime sleepiness or somnolence (EDS) - subjectivereport of difficulty in staying awake, accompanied by a ready entranceinto sleep when the individual is sedentaryExpiratory Phase - air is expelled during this phase of the breathingcycle

F

Fatigue - feeling of tiredness or weariness usually associated withperformance decrementsFiber optic Nasopharyngoscope - flexible fiber optic scope used inthe examination of nasal passages, pharynx, hypopharynx and larynx.Fibromyalgia - a disease syndrome whose primary symptoms aremuscle pain and fatigue.Flattening Index - number indicating the amount of airflow limitationcaused by partial closure of the upper airway. 0.3 indicates an openairway, 0.15 is mildly obstructed, 0.1 is severely limited airflow, and 0.0reflects a totally closed airway. Flattening Index is used to identify thecondition known as Upper Airway Resistance Syndrome (UARS), and iscontinuously recorded in both diagnostic sleep studies and CPAPtitrations.Flow Limitation – the partial closure of the upper airway impedingthe flow of air into the lungs.Forbidden Zone – the period of strongest clock-dependent alerting,usually in the evening. Prevents falling asleep.Fragmentation (pertaining to Sleep Architecture) - interruption ofa sleep stage as a result of the appearance of a lighter stage, or to theoccurrence of wakefulness, which leads to disrupted non-REM-REMsleep cycles.

G

GABA (Gamma-Amniobutyric Acid) - major neurotransmitter inthe brain, which is considered to be involved in muscle relaxation,sleep, diminished emotional reaction and sedation.Gastroesphageal Reflux Disease (GERD) - flow of stomachacid upwards into the esophagus that can cause arousals anddisrupt sleep.Genioglossus tongue advancement – a possible surgical treatmentused for sleep apnea and/or snoring, improving the airway behind thebase of the tongue. The genioglossus, the main tongue muscle,relaxes during sleep, often allowing the tongue to fall into the airway.The muscle attaches to the middle of the lower jaw. A segment ofbone containing this muscle is pulled forward and stabilized,opening the airway space behind the tongue.

H

Habitual Snorers - those who snore nearly every nightHeart Rate or beats per minute (bpm) – pace/speed of the heartmeasured in beats per minute. 60-80 is considered normal in adults.Hertz (Hz) - unit of frequency; equal to cycles per second (cps).Histogram (sleep) - graph indicating sleep stages throughout thenight.Humidification - moisture is added to the airflow as an adjunct to CPAP(Continuous Positive Airway Pressure) therapy in treating obstructivesleep apnea (OSA). Humidification can be added to the CPAP bydiverting the airflow over or through a cool or heated water reservoir(humidifier) to prevent the upper airway from drying out.Hyoid Suspension – a possible surgical procedure sometimes used inthe treatment of sleep apnea and/or snoring, designed to improve theairway behind the base of the tongue. The hyoid bone is located in theneck where some tongue muscles attach. The hyoid bone is pulledforward in front of the voice box and can open the airway space behindthe tongue.Hyperactivity – typical behavior in a child with a sleep disorderwhich is causing lack of quality sleepHypercapnia – excessive or elevated carbon dioxide in the bloodHyperirritability - Extreme irritability; seen in sleep deprived subjects.Hypersomnia – excessive, prolonged sleepHypertension -High blood pressure.Hypnagogic imagery (-hallucinations) - Vivid sensory imagesoccurring at sleep onset but particularly vivid with sleep-onset REMperiods; feature of narcoleptic REM naps.Hypnagogic startle - "sleep start" or sudden body jerk, observednormally just at sleep onset, resulting in at least momentary awakeningHypnophobia - Morbid fear of falling asleep.Hypnotics - Sleep-inducing drugs.Hypopharynx - lowermost portion of the pharynx leading to the larynxand esophagus.Hypopnea - shallow breathing in which the air flow in and out of theairway is less than half of normal--usually associated with oxygendesaturation.Hypoventilation - reduced rate and depth of breathing.Hypoxemia - abnormal lack of oxygen in the blood in the arteries.Hypoxia - deficiency of oxygen reaching the tissues of the body.

I

Imidazopyridines - New class of compounds inducing sleepiness.(Zolpidem, trade name Ambien, is in this class).Inappropriate Sleep Episodes – unplanned sleep periods often

occurring in an unsafe situation (i.e., while driving). Theseepisodes are always due to sleep deprivation.Insomnia – complaint describing difficulty in sleepingInspiratory Phase - part of the breathing cycle in which air is inhaled.Invasive – referring to a medical procedure in which a bodilyorifice or the skin must be penetrated for the purpose of collectingdata, or for diagnosing or treating a disorderIPAP - Inspiratory Positive Airway Pressure. Physician prescribedpressure for the inspiratory phase on a Bi-level CPAP device, used in thetreatment of OSA.

J

Jet Lag - disturbance induced by a major rapid shift in environmentaltime during travel to a new time zone

K

K-Alpha - type of micro arousal; K complex followed by severalseconds of alpha rhythm.K complex - sharp, negative, high-voltage EEG wave, followed by aslower, positive component. K complex, occurring spontaneously duringNREM sleep, beginning in (and defining) stage 2. K complexes can beelicited during sleep by external (particularly auditory) stimuli as well.

L

Laser assisted uvulopalatoplasty (LAUP) - can eliminate ordecrease snoring but has not been shown to be effective in thetreatment of sleep apnea.Leg Movement - Leg movements are recorded in both diagnostic sleepstudies and titration studies.Letter of Medical Necessity (LMN) - certification by a physician thatthe prescribed item(s) is/are medically indicated, reasonable andnecessary with reference to the standards of medical practice andtreatment of a patient's conditionLight-Dark Cycle - periodic pattern of light (artificial or natural)alternating with darknessLight Sleep - term used to describe non-REM sleep stage 1, andsometimes, stage 2.Light Therapy - used in the treatment of SAD (Seasonal AffectiveDisorder) and other conditions. Exposes the eyes to light ofappropriate intensity and duration and at the appropriate time ofday to affect the timing, duration and quality of sleep.Limit-Setting Sleep Disorder – disorder due to child’s difficulty infalling asleep by delaying and refusing to go to bedLinear Sleepiness Rating Scale - measure of subjective sleepiness.

The scale contains a horizontal line, 100 mm in length --the rightextreme is labeled "Very Sleepy" and the left extreme is labeled "VeryWide Awake."

M

Macroglossia - large tongue; usually a congenital disorder (present atbirth)Maxillofacial - pertaining to the jaws and face.Mandibular Maxillary Osteotomy and Advancement (MMOA) -procedure developed for patients with retrolingual obstruction, patientswith retropalatal and retrolingual obstruction who have not respondedto CPAP and uvulopalatopharyngoplasty (UPPP).Melatonin - hormone secreted by the brain’s pineal glandMicro-arousal - partial awakening from sleepMicro-sleep - period lasting up to a few seconds during which thepolysomnogram suddenly shifts from waking characteristics to sleep.Mixed (sleep) apnea - interruption in breathing during sleepbeginning as a central apnea then becoming an obstructive apnea.Monocyclic - a single major sleep period and a single major wakeperiod in a 24-hour day.Motor Activity in Sleep - any muscular movement during sleepMotor Atonia – the absence of muscle activity during sleepMovement arousal - body movement associated with arousal orawakening; a sleep scoring variable.Movement time - term used in sleep record scoring to denote whenEEG and EOG tracings are obscured for more than 15 seconds due tomovement.Multiple sleep latency test (MSLT) - a series “nap tests” utilizedin the assessment of excessive daytime sleepiness.Muscle Tone – amount of tension in a muscle.Myoclonus - muscle contractions in the form of "jerks" or twitches.

N

Nap - short period of planned sleep generally obtained at a timeseparate from the major sleep period.Narcolepsy - sleep disorder characterized by excessivesleepiness, cataplexy, sleep paralysis, hypnogogic hallucinations,and an abnormal tendency to pass directly from wakefulness intoREM sleepNasal Airflow/Nasal Ventilation - recording of the completerespiratory cycle by measuring inspiratory and expiratory airflowNational Commission on Sleep Disorders Research (NCSDR) - thecommission (created by the U.S. Congress in 1990) conducted acomprehensive study of the social and economic impact of sleepdisorders in America and made recommendations based on its findings to

the Congress in January 1993Neurology - branch of medicine that referring to the nervous systemand its diseasesNeurotransmitters - endogenuous chemical components that arereleased from axon terminals of one neuron and transmit the signalto the next neuron by combining with its receptor molecules.Neurotransmitters important in the control of sleep and wakefulnessinclude: norepinephrine, serotonin, acetylcholine, dopamine,adrenaline and histamine.Nightmare - unpleasant and/or frightening dream occurring in REMsleep (different from a night terror)Night Terrors - also known as sleep terrors, or pavor nocturnus. Nightterrors are characterized by an incomplete arousal from slow wavesleep. If, the individual is awakened during a night terror, he/she isusually confused and does not remember details of the event. Nightterrors are different from nightmares; if an individual is awakenedduring a nightmare, he/she functions well and may have some recall ofthe nightmare.Nocturia - excessive, often frequent, urination during the nightNocturnal - "Of the night;" pertaining to events happening duringsleep or the hours of darkness.Nocturnal Confusion - episodes of delirium and/or disorientationnear or during nighttime sleep; often seen in victims of AlzheimersDisease and more common in the elderlyNocturnal sleep-related eating disorder (NS-RED)- Getting up duringthe night and eating while sleepwalking. No recall in the morning.Nocturnal Enuresis (Bedwetting) - urinating while asleepNon-Invasive - Medical procedure not penetrating the skin or a bodycavity.NREM or non-REM sleep - characterized by slower and larger brainwaves and little or no dream behavior; quiet sleep, slow-wave sleep;approximately 80% of sleepNREM Sleep Intrusion - brief period of NREM sleep patternsappearing in REM sleep; a portion of NREM sleep not appearing in itsusual sleep cycle position

O

Obesity-Hypoventilation Syndrome - term applied to obeseindividual’s hypoventilating during wakefulness.Obstructive Sleep Apnea - cessation of airflow (at least 10 seconds)in the presence of continued inspiratory effort; cessation of breathingduring sleep, due to a mechanical obstruction, such as a semi-collapsedtrachea, tongue relaxed to back of the throat, or a large among of tissuein the uvula area.Obstructive Sleep Hypopnea - periodic and partial closure of the

throat during sleep resulting in reduced air exchange at the levelof the mouth and/or nostril.Ondine's Curse - the respiratory center in the brain is unable tostimulate breathing in response to an increased amount of carbondioxide in the blood. Ondine's Curse or central alveolar hypoventilationtypically worsens during sleep.Optimum Sleep - average amount of sleep needed every night by anindividual.Oxygen Desaturation - less than normal amount of oxygen carried byhemoglobin in the blood; values below 90% are considered abnormalOxygen Saturation - measure of oxygen carried by hemoglobin in theblood. Normal values 90% - 100%.Oximeter (Pulse) - gives estimates of arterial oxyhemoglobinsaturation (SaO2) by utilizing selected wavelengths of light to noninvasively determine the saturation of oxyhemoglobin (SpO2)Oximetry (Pulse) - continuous monitoring of oxygen saturation ofarterial blood from a pulse oximeter; the sensor is usually attached tothe finger.O2 - Chemical symbol for oxygen. Criterion lowest percent O2saturation: Greater than 85%=mild, 80% to 85%=moderate, lessthan 80%=severe

P

Parasomnia - an event happening during sleep, or induced orexacerbated by sleep, such as sleepwalking or asthma; not a dyssomnia.Paroxysmal nocturnal dyspnea (PND) - respiratory distress andshortness of breath due to pulmonary edema, appearing suddenly andoften awakening the sleeping individual.Pathological Sleep - abnormal sleep patterns.Pavor Nocturnus (Night Terrors) - See Night Terrors.Perceptual Disengagement - change in consciousness at theonset of sleep when environmental stimuli are no longerperceived, and there is no longer any conscious, meaningfulinteraction with the environment.Periodic Breathing - repetitive apnea pauses, common in prematureinfants.Periodic Limb Movement Disorder - also known as periodic legmovements and nocturnal myoclonus. Characterized by periodicepisodes of repetitive and highly stereotyped limb movements occurringduring sleep. The movements are often associated with a partial arousalor awakening; however, the patient is usually unaware of the limbmovements or frequent sleep disruption. Between the episodes, the legsare still. There can be marked night-to-night variability in the number ofmovements or in the existence of movements.Persistent Insomnia - continuing insomnia responding poorly to

treatment.Pharynx - area posterior to the nares and the oral cavity; passagewayfor air from the nasal cavity and/or the mouth to the lungs via thelarynx and the trachea, for food and liquids from the mouth to theesophagusPhase advance - movement to a position earlier in the 24 hour sleep -wake cycle of a period of sleep or wake; for example, a shift of thesleep phase from 11 p.m. - 7 a.m. to 8 p.m. - 4 a.m.Phasic (Event/Activity) - brain, muscle, or autonomic related eventof a brief and episodic nature occurring in sleep. Usually occur duringREM sleep, such as eye movements and/or muscle twitchesPhotoperiod - duration of light in a light/dark cycle.Pickwickian Syndrome - obesity accompanied by somnolence,lethargy, chronic hypoventilation, hypoxia, and secondarypolycythemia (a condition marked by an abnormal increase in thenumber of circulating red blood cells); usually has severe obstructivesleep apneaPineal Gland - gland in the brain secreting the hormone melatonin.PLMD-Arousal Index - number of sleep-related periodic legmovements per hour of sleep that are associated with an EEG arousalPolycyclic - multiple sleep periods and wake periods in a 24-hour day.PO2 - partial pressure of oxygen (O2) in the blood. A value above 60 isusually considered a safe level: lower than 60 indicated hypoxemia andpotential danger for the patient.Polysomnogram (PSG) - continuous and simultaneous recording ofphysiological variables during sleep, i.e., EEG, EOG, EMG (the threebasic stage scoring parameters), EKG, respiratory air flow, respiratoryexcursion, lower limb movement, and other electrophysiologicalvariables.Polysomnograph - biomedical instrument for the measurement ofmultiple physiological variables of sleepPolysomnographic Technologist - health care professional trained inperforming diagnostic sleep studiesPost-Prandial Drowsiness - sleepiness that occurs after a meal,usually lunchPost-Traumatic Stress Disorder - re-experiencing of a traumaticevent in the form of repetitive dreams, recurrent and intrusive daytimerecollections, and/or dissociative flashback episodes.Premature morning awakening - early termination of the sleepperiod in a sleep maintenance DIMS due to inability to return tosleep after the last of several awakeningsPrescribed CPAP Pressure - pressure(s) or settings determined by aCPAP titration sleep study, which a physician prescribes for a patient'sCPAP therapy machinePulse Oximetry - non-invasive measure of oxygen saturation; that isthe amount of oxygen saturated in the hemoglobin in terms of

percentage; not as accurate as the values obtained from an arterialblood gases (ABG) test and should only be used as a gauge ofoxygenation. Normal ranges are between 95-100%.

Q

Quiet Sleep - The term frequently used instead of NREM sleep todescribe the sleep of infants.

R

Radiofrequency (RF) - Electromagnetic radiation in the frequencyranges 3 kilohertz (kHz) to 300 gigahertz (GHz); considered to includemicrowaves and radio waves. Microwaves occupy the spectral regionbetween 300 GHz and 300 MHz, while RF or radio waves include 300 MHzto 3 kHz.Radiofrequency (RF) Procedure (also known as Somnoplasty) -procedure for treating nasal obstruction, snoring and in some cases,sleep apnea. The procedure uses radio wave energy to reduce snoringand the size of the soft palate.RDI - Respiratory Disturbance Index, includes all respiratory events perhour.REM sleep, rapid eye movement sleep - sleep characterized by theactive brain waves, flitting motions of the eyes, and weakness of themuscles; most dreaming occurs in this stage, which accounts for about20% of sleep in adults.REM Density - A function that expresses the frequency of eyemovements per unit of time during REM sleep.REM-Associated Disorders - Sleep disturbances that occur in REMsleep.REMS latency - The period of time in the sleep period fromsleep onset to the first appearance of stage REMS.REM Motor Atonia - The active suppression of activity in theantigravity and voluntary muscles during REM sleep. The musclesare completely flaccid and limp.REM onset - designation for commencement of a REM period; usedalso as a shorthand term for a sleep-onset REM periodREM period - REM portion of a NREM-REM cycle; early in the night itmay be as short as a half-minute, whereas in later cycles longer thanan hour.REM rebound or recovery - lengthening and increase in frequencyand density of REM periods, which results in an increase in REMpercent above base line. REM rebound follows REM deprivation oncethe inhibitory influence is removedREM Sleep Behavior Disorder (RBD)- disorder in which REM motoratonia is partially or completely absent and the individual acts outthe ongoing dream. The behavior in REM behavior disorder is often

correlates with the ongoing, hallucinatory REM dream episode.REM Sleep Episode - REM sleep portion of a N REM-REM sleep cycle.Early in the first sleep period, episodes may be only several minutes induration. Later REM episodes almost are always longer, 20 to 30minutes up to an hour.REM Sleep Intrusion - brief interval of REM sleep appearing out of itsusual positioning in the NREM-REM sleep cycle.REM Sleep Latency - interval from sleep onset to the first appearanceof REM sleepREM Sleep Onset - designation for the first epoch of a REM sleepepisodeREM Sleep Percent - proportion of total sleep time occupied by REMsleepREM Sleep Rebound - compensatory increase in REM sleep followingexperimental reduction. Extension of time in, and an increase infrequency and density of REM sleep episodes; usually an increase in REMsleep percent of total sleep time above baseline valuesRespiratory Care Practitioner (RCP) - licensed health careprofessional specifically trained in cardiopulmonary assessment,diagnostics, therapy administration, and patient education, includingthe identification and treatment of sleep disordersRestless Legs Syndrome (RLS) - sleep disorder characterized by adeep creeping, or crawling sensation in the legs that tends to occurwhen an individual is not moving. There is an almost irresistible urgeto move the legs; the sensations are relieved by movement.Restlessness (Referring to Quality of Sleep) - Persistent orrecurrent body movements, arousals, and/or brief awakenings in thecourse of sleep

S

Sedatives - compounds tending to calm, and reduce nervousness orexcitement and foster sleepSedentary Situation - not requiring physical activity, e.g.working at a desk, sitting in a meeting or in a theater, watchingtelevision.Septoplasty - surgery on the nasal septum (dividing the nasalpassage)Serotonin - neurotransmitter in the brain that modulates mood,appetite, sexual activity, aggression, body temperature and sleepShiftwork - working hours outside of the conventional daytime hours of9:00 a.m. to 5:00 p.m.Sleep - a state marked by lessened consciousness, lessenedmovement of the skeletal muscles, and slowed-down metabolismSleep Apnea - cessation of breathing for 10 or more seconds duringsleep

Sleep architecture - N REM/REM stage and cycle infrastructure of sleepunderstood from the vantage point of the quantitative relationship ofthese components to each otherSleep cycle - synonymous with NREM-REM cycleSleep Debt - result of recurrent sleep deprivation which occurs overtime when an individual does not experience a sufficient amount of therestorative daily sleep that is required to maintain a sense of feelingrested and refreshed. .Sleep Deprivation - acute or chronic lack of sufficient sleep.Sleep Disorders - broad range of illnesses arising from many causes,including, dysfunctional sleep mechanisms, and abnormalities inphysiological functions during sleep, abnormalities of the biological clock,and sleep disturbances that are induced by factors extrinsic to the sleepprocessSleep efficiency (SE) - proportion of sleep in the period potentiallyfilled by sleep--ratio of total sleep time to time in bedSleep Episode - interval of sleep that may be voluntary or involuntarySleep Extension - extending sleep time by increasing the time in bedSleep Fragmentation - brief arousals occurring throughout thenight, reducing the total amount of time spent in the deeper levelsof sleep.Sleep hygiene - conditions and practices that promote continuous andeffective sleep, including regularity of bedtime and arise time;conforming time spent in bed to the time necessary for sustained andindividually adequate sleep (i.e., the total sleep time sufficient to avoidsleepiness when awake); restriction of alcohol and caffeine beveragesin the period prior to bedtime; employment of exercise, nutrition, andenvironmental factors so that they enhance, not disturb, restful sleepSleep Hyperhydrosis - excessive sweating during sleep.Sleep Inertia - feelings of grogginess and/or sleepiness that persistlonger than 10 to 20 minutes after waking upSleep interruption - breaks in the sleep architecture resulting inarousal and wakefulnessSleep latency - time period measured from "lights out," or bedtime, tothe beginning of sleepSleep log (-diary) - daily, written record of an individual's sleep-wakepattern containing such information as time of retiring and arising, timein bed, estimated total sleep period, number and duration of sleepinterruptions, quality of sleep, daytime naps, use of medications orcaffeine beverages, nature of waking activities, and other dataSleep-maintenance DIMS or insomnia - disturbance in maintainingsleep once achieved; persistently interrupted sleep without difficultyfalling asleepSleep Mentation - thoughts, feelings, images, perceptions,hallucinations, and active dreams taking place during sleepSleep onset - transition from wake to sleep, normally into NREM

stage 1 (but in certain conditions, such as infancy and narcolepsy,into stage REMS)Sleep Onset Imagery - images and experiences during the momentsfollowing the transition from wake to sleepSleep-onset REM period - atypical beginning of sleep by entrancedirectly into stage REMSleep paralysis - waking and not being able to move for a short periodof time, usually occurs out of REM (dream) sleep.Sleep pattern (24 hour sleep-wake pattern) - individual's clock hourschedule of bedtimes and rise times as well as nap behavior: may alsoinclude time and duration of sleep interruptionsSleeping Pills - compounds that have a sedative effect, used toproduce sleepinessSleep Related Accidents - accidents caused by individuals whowere sleep deprived and who, as a result, had impaired judgmentSleep Restriction - limitation of the number of hours in bedSleep spindle - episodically appearing, spindle-shaped aggregate of12-14 Hz waves with a duration of 0.5-1.5 seconds, one of theidentifying EEG phenomena of NREM stage 2 sleepSleep Stage Demarcation - significant polysomnographycharacteristics that distinguish the boundaries of the sleep stages.Sleep stage NREM - major sleep state apart from REMS; comprisessleep stages 1-4Sleep stage 1 - a stage of NREM sleep occurring after wake. Itscriteria consist of a low-voltage EEG with slowing to theta frequencies,alpha activity less than 50%, EEG vertex spikes, and slow rolling eyemovements; no sleep spindles, K-complexes, or REMS. Stage 1normally assumes 4-5% of total sleep.Sleep stage 2 - a stage of NREM sleep characterized by sleep spindlesand K complexes against a relatively low-voltage, mixed-frequency EEGbackground; high-voltage delta waves may comprise up to 20% ofstage 2 epochs; usually accounts for 45-55% of total sleep time.Sleep stage 3 - a stage of NREM sleep defined by at least 20 and notmore than 50% of the period (30 second epoch) consisting of EEG wavesless than 2 Hz and more than 75 uV (high -amplitude delta waves); a"delta" sleep stage; with stage 4, it constitutes "deep "N REM sleep;appears usually only in the first third of the sleep period; usuallycomprises 4-6% of total sleep time.Sleep stage 4 - all statements concerning NREM stage 3 apply to stage4 except that high-voltage, slow EEG waves, cover 50% or more of therecord; NREM stage 4 usually takes up 12-15% of total sleep time.Somnambulism, sleep terror, and sleep-related enuresis episodesgenerally start in stage 4 or during arousals from this stageSleep stage REM - the stage of sleep found in all mammal studies,including man, in which brain activity is extensive, brain metabolism isincreased, and vivid hallucinatory imagery, or dreaming occurs (in

humans). Also called "paradoxical sleep" because, in the face of thisintense excitation of the CNS and presence of spontaneous rapid eyemovements, resting muscle activity is suppressed. The EEG is a low-voltage, fast-frequency, non alpha record. Stage REMS is usually 20-25% of total sleep time.Sleep structure - similar to sleep architecture. Sleep structure, inaddition to encompassing sleep stage and cycle relationships, assessesthe within-stage qualities of the EEG and other physiological attributes.Sleepiness (somnolence, drowsiness) - difficulty in maintaining thewakeful state so that the individual falls asleep if not actively keptaroused; not simply a feeling of physical tiredness or listlessnessSleep talking - talking in sleep takes place during stage REMS,representing a motor breakthrough of dream speech, or in the course oftransitory arousals from NREMS and other stages. Full consciousness isnot achieved and no memory of the event remains.Sleepwalker or Sleepwalking - individual subject to somnambulism(one who walks while sleeping). Sleepwalking typically occurs in thefirst third of the night during deep NREM sleep (stages 3 and 4).Sleep-wake, 24 hour cycle - the clock hour relationships of the majorsleep and wake phases in the 24 hour cycle: similar to sleep pattern.Sleep-wake shift (-change, -reversal) – sleep wholly or partiallymoved to a time of customary waking activity, and the latter is movedto the habitual sleep period; common in jet lag and shift work.Sleep-Wake Transition Disorder - disorder occurring during thetransition from wakefulness to sleep or from one sleep stage toanother; a form of parasomniaSlow wave sleep (SWS) - sleep stages 3 and 4Smart PAP (Smart CPAP) - (Smart [Continuous] Positive AirwayPressure) Medical device used in the treatment of obstructive sleepapnea providing preset levels of continuous airflow, and automaticallyadjusting to keep the breathing passages open by sensing changes inairway integrity. The air flows from the device through a tube thatconnects to a nose or face mask.Snoring - noise produced primarily with inspiratory respiration duringsleep owing to vibration of the soft palate and the pillars of theoropharyngeal inlet. Many snorers have incomplete obstruction of theupper airway, and may develop obstructive sleep apnea.Soft Palate - membranous and muscular fold suspended from theposterior margin of the hard palate and partially separating the oralcavity from the pharynxSomatic Complaints - awareness of pain or problems in the bodySomnambulism - walking while asleepSomnifacient - inducing sleep; hypnotic, as in a drugSomnolence - prolonged drowsiness or sleepiness.Somnoplasty - commercial name for radiofrequency treatment ofcertain sleep disorders

Soporific - causing or tending to cause sleepSpindle REMS - condition in which sleep spindles persist atypically inREMS; seen in chronic DIMS conditionsStanford Sleepiness Scale (SSS) - 7-point rating scale consistingof seven numbered statements describing subjective levels ofsleepiness/alertnessSubjective Sleepiness - feelings of sleepinessSubstance Abuse - excessive use of alcohol or drug; substancescan cause sleep disturbancesSubwakefulness syndrome - syndrome defined as a defect in theCNS support system for waking. The few individuals reported withsubwakefulness syndrome have daytime drowsiness and daytime sleepepisodes that are always composed of NREMS stages 1 or 2. The napsoccur repetitivelySudden Infant Death Syndrome (SIDS) - sudden and unexpecteddeath of an apparently healthy infant, whose death remainsunexplained after the performance of an adequate postmorteminvestigation. Death usually occurs during sleep. SIDS is aclassification that is used to describe a deceased infant. It is not adisease, nor can it be a diagnosis for a living baby.Synchronization - chronobiological term used to indicate that two ormore rhythms recur with the same phase relationship. In an EEGtracing, the term is used to indicate increased amplitude with anoccasional decreased frequency of the dominant activities.Synchrony - scheduling sleep to synchronize with the biological clock.

T

Tachycardia - rapid heart rate, usually defined by a pulse rate of over100 beats per minute (bpm).Thermocouples - small devices placed near the nostrils or mouth tomeasure air flow by sensing temperature changes; expired air iswarmer than inspired air.Thermoregulation - regulation of body temperature in mammals.Theta waves - EEG activity with a frequency of 4-8 HzThoracic Excursion - thoracic (chest) movement, indicatingrespiratory effort. Usually measured by the placement of a sensorband, which includes a strain gauge around the chest. The sensorband records chest wall movement associated with respirations..Tidal Volume - amount of air that passes in and out of the lungs inan ordinary breath; usually expressed in litersTitration - progressive, stepwise increase in CPAP pressure appliedduring a polysomnogram to establish the optimal treatment pressureTolerance - in pharmacology, refers to the reduced responsiveness to adrug's action as the result of previous continued and/or multipleexposure

Tonic (Event/Activity) - brain, muscle, or autonomic events, whichare continuous. Usually refers to continuous activity (e.g. muscleatonia) during REM sleep.Tonsils - pair of prominent masses of lymphoid tissue that are locatedopposite each other in the throat between the anterior and posteriorpillars of the fauces (the narrow passage from the mouth to the pharynxsituated between the soft palate and the base of the tongue).Composed of lymph follicles grouped around one or more deep crypts.Tonsillectomy - surgical removal of the tonsilsTotal Recording Time - duration of time from sleep onset to finalawakening. I n addition to total sleep time, it is comprised of the timetaken up by wake periods and movement time until wake-up.Total sleep period - period of time measured from sleep onset to finalawakening. In addition to total sleep time, it is comprised of the timetaken up by arousals and movement time until wake-upTotal sleep time (TST) - amount of actual sleep time in a sleepperiod; equal to total sleep period less movement and awake time.Total sleep time is the total of all REMS and NREMS in a sleep period.Tracheotomy - surgical procedure to create an opening in the trachea(windpipe) so that one can breatheTracheostomy - refers to the opening in the trachea. As a treatmentfor severe obstructive sleep apnea, a tube to assist oxygenation andventilation and/or to overcome an obstruction in the airway locatedsuperiorly.Transducer - device designed to convert energy from one form toanotherTransient Arousals - brief awakenings from sleepTransient Insomnia - difficulty sleeping for only a few nightsTricyclic Antidepressants - medication for depression. Most tricyclicantidepressants also reduce REM sleep; also used to control cataplecticattacks, hypnogogic hallucinations, and sleep paralysis.Tumescence (penile) - hardening and expansion of the penis: penileerection. Commonly referred to as nocturnal penile tumescence (NPT)in sleep recordings.Turbinate - small, shelf-like, cartilaginous structures covered bymucous membranes, which protrude into the nasal airway to helpwarm, humidify, and cleanse inhaled air on its way to the lungs.Twilight Zone - slang popular term to describe the waking state ofindividuals whose MSLT scores are 5 minutes or less. Such individualsare usually sleep deprived or suffer from a sleep disorder.Twitch (Body Twitch) - very small body movement such as a local footor finger jerk which is not usually associated with an arousal.

U

Unattended CPAP Titration Study - sleep study that is usually

performed in the home, after determining that a patient has a sleeprelated breathing disorder such as OSA or Upper Airway ResistanceSyndrome, and is likely to benefit from CPAP therapy.Unintended Sleep Episode - sleep episode that is not planned andmay happen during an activity in which such an episode is hazardous,such as when driving a car or working with machineryUpper Airway - part of the respiratory anatomy that includes thenose, nostrils, sinus passages, septum, turbinates; the tongue, jaws,hard and soft palate, muscles of the tongue and throat, etc.Upper Airway Resistance Syndrome (UARS) - part of the spectrumof obstructive sleep-related breathing disorders in which repetitiveincreases in resistance to airflow in the upper airway lead to briefarousals and daytime fatigue. Apneas and hypopneas (see RDI) may betotally absent. Blood oxygen levels can be in the normal range.Uvula - small soft structure hanging from the bottom of the soft palatein the midline above the back of the tongue.Uvulopalatopharyngoplasty (UPPP) - also abbreviated as UPP or UP3this operation is performed on the throat to treat snoring and sleepapnea. UPPP is an accepted means of surgical treatment has a curativerate of less than 50%. Scientific evidence suggests that UPPP worksbest in retropalatal and combination retropalatal and retrolingualobstruction

W

Wake time - total time that is scored awake in a polysomnogramoccurring between sleep onset and final wake-upWhite Noise - mixture of sound waves extending over a wide frequencyrange that may be used to mask unwanted noise that may interfere withsleepWilkinson Addition Test - performance test; numbers addedfor one hour. Often included in a battery of tests to measure theimpact of acute or chronic sleep loss.Withdrawal - effects experienced when a patient stops taking sleepingpills.

Z

Zeitgeber - environmental time cue that entrains biological rhythms to aspecific periodicity. Known Zeitgebers are light, melatonin and physicalactivity. To be effective, these signals must occur when the biologicalclock is in a responsive phase.

Sleep Links

The American Sleep Apnea Association-

http://www.sleepapnea.orgAmerican Academy of Sleep Medicine - http://www.aasmnet.orgHealthology - http://www.healthology.com/sleepdisordersNational Sleep Foundation - http://www.sleepfoundation.orgNational Sleep Technologies - http://www.natsleep.comSleep Home Pages - http://www.sleephomepages.comSleep Medicine Home Page - http://www.cloud9.net/~thorpySleepNet - http://www.sleepnet.comTalk About Sleep - http://www.talkaboutsleep.comThe Sleep Well - http://www.stanford.edu/~dement

ApLab: What is it? The ApLab™ is a respiratory nasal pressure sensor thatprovides a complete recording of your breathing pattern duringsleep. It is FDA approved and must be prescribed by a physician. It is the size of a pager and contains proprietary electroniccircuitry with embedded software.It is tethered by a flexible tube toa disposable, lightweight nasal cannula that is conveniently wornwhile sleeping at home. When you complete the test, return the unit to AGC or yourprescribing physician for data analysis and report generation.

How does it work?

Simple explanation:

Patient attaches the lightweight ApLab to his/her arm with theincluded armband.

Patient adjusts the nasal cannula; the cannula prongs must bepositioned inside the nostrils.

Patient adjusts the collar until you have a snug comfortable fit. Patient pulls out the start strip and goes to sleep. Please note the

“System Ready” indicator light will turn on once the start strip isremoved. After 1 minute it will start to slowly flash on and off every5 seconds.

The next morning the patient removes the ApLab. He/she throws away the armband and nasal cannula. He/she fills out the patient information form that is enclosed. The patient returns the ApLab unit via mail to AGC or the referring

doctor for Analysis. AGC can send the patient’s results to the prescribing physician, who

will then see the patient at a return visit to discuss the results andpossible treatment options.

Clinical explanation:

The ability to screen for Sleep Disordered Breathing (SDB) using a singlechannel measuring just nasal respiratory pressure is based on thehypothesis that the primary pathophysiological event in SDB is abnormalbreathing. Measuring breathing extremely well reduces the need formeasuring other channels of information since most of the other channels ofinformation that are routinely measured to diagnose SDB are consequencesof abnormal breathing. For instance, this includes oxygen desaturation,respiratory effort, and EKG changes.

The technical accomplishment is that AGC has invented a way to measurebreathing using a pressure sensor and proprietary electronics which coversa broader bandwidth to record more breathing information. This results inless distortion to produce a truer record. The ApLab™ uses a highersampling rate to produce more accurate readings.

The ApLab™ system is composed of two primary components; a DataAcquisition Unit (DAU) and an Analysis Package. The DAU is a physicianprescribed, respiratory data collection system used at home by the patient.The Analysis Package is a software application designed to analyze andgenerate reports based upon data gathered by the DAU.

The patient attaches the lightweight DAU to his/her arm with the includedarm band, adjusts the nasal cannula, pulls out the start strip and goes tosleep. The armband and nasal cannula are single use components of thedevice. The DAU samples dynamic respiratory pressures throughout thesleep cycle, collecting up to 8 hours of data. After completion, the patientreturns the DAU for Analysis. The Analysis Package is an applicationdesigned for WindowsTM Operating Systems. It transfers data from the DAU,allows on screen data review and generates reports.

Features Ultra low power Temperature compensated pressure transducer technology Memory storage – collects 8 hours of breathing while asleep USB I/O High speed USB port Software that provides auto scored data Patient results are provided in both Windowsbased CD ROM or

electronic hard copy report.

Benefits Easy to use – patient attaches the ApLab to his/her arm, arranges the

nasal cannula & pull the start strip. Comfortable – light weight electronic data recording device, the

ApLab is the size of a pager. Convenient – provides at home testing for patients. Accurate – provides a breath-by-breath recording of 8 hours of sleep. Cost effective – enables clinics & physicians to test greater number

of patients in a timelier manner.

Quality Assurance When compared, the ApLab and PSG were equivalent in

measuring Apneas and Hypopneas. Using an AHI>1 0, the ApLab had a sensitivity of 89% and a

positive predictive value (PPV) of 100% verses the PSG. The ApLab and PSG are equivalent when compared on a breath-by-

breath basis.

ApLab History

AGC is committed to developing novel approaches to the screening,diagnosis and treatment of sleep related breathing disorders. Severaladditional products are in the pipeline, including a disposable screeningdevice, a low cost diagnostic device, and a novel approach to treatment.

Interest in OSAS has become more intense in recent years. Currentdiagnostic techniques require an overnight stay at a sleep clinic and cancost as much as $2,400. With the high frequency of snoring in the adultpopulation and the difficulty in selecting and expediting diagnosticevaluation of those patients, there is a critical need for an easy to use at-home screening tool.

Scientists at the National Institute of Health have linked sleep apnea withserious health problems such as hypertension and cardiovascular disease.In the U.S., about 15 percent of the adult population is suspected to haveOSAS but only about 5 to 7 percent of the estimated 20 million Americanswith OSAS are diagnosed due to the lack of simple screening equipment – a

void Sector Medical will fill when its device is launched in late 2003.

AGC’s goal was to develop the best methodology to record breathing duringsleep by using the latest advances in electronics. Our technical team isresponsible for the accomplishment. Our target is to make Sleep Apneascreening a standard part of routine physicals for affected adults andchildren.

The ApLab is a reliable, low cost tool that produces a complete record ofbreathing during sleep. With this tool, physicians will now be able to reviewthe number of apneas, hypopneas and their duration as well as otherrespiratory events such as normal breathing, snoring, upper airwayresistance and respiratory arousals.

Clinical Studies

Study #1

SYNOPSIS

Sponsor: AGC Biomedical Devices, Inc.

Product Name: ApLab™

Study Title: A Comparison of the ApLab™ to Polysomnography in PatientsWith Obstructive Sleep Apnea Syndrome

Principal Investigator: Abul F. Matin, MD, PhD

Study Center: Sleep Disorders Center ofGeorgia, Inc 5505 PeachtreeDunwoody Rd, NE Suite 380Atlanta, GA 30342

Date First Patient Enrolled: 9/25/2002

Date Last Patient Enrolled: 11/06/2002

Objective: The objective of this study was to compare the safety andeffectiveness of the ApLab™ to polysomnography in approximately tenpatients with Obstructive Sleep Apnea syndrome.

Methodology: This was a pilot, open label, simultaneous comparisonbetween polysomnography (PSG) and the ApLab™ in approximately tenpatients with Obstructive Sleep Apnea syndrome. Patients presenting to thesleep clinic had a brief medical history, recording of concomitant therapy toinclude medications, and vital signs measurement prior to the start of thesleep study. Adverse events were collected and were monitored throughoutthe study. The patients then underwent a diagnostic sleep study to includerecordings of central and occipital electroencephalograms,electrooculogram, submental electromyogram, electrocardiogram, oxygensaturation, chest and abdominal wall movements, limb movement andrespiratory airflow using a thermistor. Respiratory pressure wassimultaneously recorded with the ApLab™. At study end, vital signs weremeasured and adverse events were collected. Patients were allowed todiscontinue at any time from the trial for any reason.

Number of patients planned and analyzed: Ten planned, nine analyzed.Results from one patient were not analyzed due to battery malfunction inthe ApLab™.

Diagnosis and main inclusion criteria: Patients with a diagnosis ofObstructive Sleep Apnea syndrome or with a referring diagnosis of theObstructive Sleep Apnea syndrome.

1. Any age range.2. Either gender.3. Signed written informed consent prior to the initiation of any studyrelated events.

Exclusion criteria: Patients who, in the opinion of the investigator:Had an acceptable risk for participation due to disease related criteriaHad an acceptable risk for participation due to concomitant medicalor psychiatric illness or concomitant medication

Test Product: ApLab™ model 801 D0020

Duration of Sleep Monitoring: The range for the nine patients was 1:04:00to 6:43:00 hours with a mean of 4:06:33 hours. The average length oftime that the ApLab™ device was worn by the nine patients in this studywas 4:46:01.

Reference Product: SensorMedics SomnoStar Alpha Series 4 SleepDiagnostic Instrument Software Revision A.

Efficacy Criteria: The primary efficacy variable was respiratory events,apneas and hypopneas during the observation period. Hand scoring ofapneas and hypopneas during standard polysomnography was comparedto the results generated by the ApLab™. The secondary efficacy variablethat was determined was a breath-by-breath comparison between the

ApLab™ and the PSG.

Safety Criteria: Safety assessments included monitoring for adverseeffects throughout the study and vital signs assessment at the beginningand end of the study. Reports of adverse effects and intercurrent illnesseswere elicited by general questioning.

Safety was also assessed during the study by the use of a PSG. ThePSG included recordings of central and occipital electroencephalograms,electrooculogram, submental electromyogram, electrocardiogram,oxygen saturation, chest and abdominal wall movements, limbmovement, and respiratory airflow using a thermistor.

Statistical Methods: Ten patients were enrolled and nine analyzed. Thehand scored PSG was the standard utilized in the determination of thesensitivity and Positive Predictive Value (PPV) for ApLab™ on sleep apneaand hypopnea events. The AHI between ApLab™ and PSG was tested usingequivalence test for paired data based on the ratio of means. Descriptivestatistics, n, mean, SD, 70% confidence interval (CI) of mean, median, min,and max were calculated and tabulated.

The breath-by-breath counts between ApLab™ and PSG were compared atthree time intervals, First (first ten minutes), Middle (middle ten minutes)and End (last ten minutes) with PSG as standard. They were analyzed usingequivalence test for paired data based on the ratio of means. Two one-sidedt-tests procedure and the 90% confidence intervals approach based onFieller’s theorem were performed. The equivalence range used was [0.9,1/0.9=1.1111]. Descriptive statistics, n, mean, standard error of mean,geometric mean, median, standard deviation of mean, variance, min, andmax were calculated and tabulated.

Efficacy Results: The ApLab™ and manually scored PSG were equivalentin mean AHI. The ApLab™ sensitivity was 69% with a PPV of 65% on anapnea and hypopnea event count when compared to a manually scoredPSG.The autoscored PSG sensitivity was 21% with a PPV of 58% on an apneaand hypopnea event count when compared to a manually scored PSG.The ApLab™ and autoscored PSG were statistically equivalent on PPVand the ApLab™ was statistically superior on sensitivity.When compared to an AHI of 10, the ApLab™ produced a sensitivity of89% with a PPV of 100% when compared to a manually scored PSG todetermine if a patient has OSAS.The ApLab™ and PSG are equivalent on a breath-by-breath basis at allthree time intervals. The ApLab™ provides a complete record of breathingto confirm the AHI scoring.

Safety Results: Nine patients wore the ApLab™ for an average of 4:46:01

with no device related adverse effects. There were no abnormal vitalsigns related to the ApLab™. There were no early terminations.

Conclusions: The ApLab™ provided a complete record of breathing duringsleep. These results demonstrate that the ApLab™ can be used to screenfor and aid in the diagnosis of Obstructive Sleep Apnea syndrome. Theresults of this study also demonstrate that the ApLab™ was safe and welltolerated.

Study # 2

A clinical study with Emory has been commissioned. Results will be publishedonce the study is completed.

Study # 3

Synopsis

Sponsor: AGC Biomedical Devices, Inc.

Product Name: ApLab™

Study Title: A Crossover Comparison of the ApLab to Polysomnographyin Subjects With Obstructive Sleep Apnea Syndrome

Principal Investigator: Charles C. Wells, Jr, MD

Study Center: SleepMed of CentralGeorgia 770 HemlockStreetP.O. Box 1035Macon, GA 31202

Date First Patient Enrolleed: 11/13/03

Date Last Patient Enrolled: 3/9/04

Objective: The objective of this study was to compare the safety andeffectiveness of the ApLab to polysomnography (PSG) in approximately 30patients with obstructive sleep apnea syndrome.

Methodology: This is a randomized, crossover study for assessing theagreement between polysomnography and the ApLab in 30 patients referredfor obstructive sleep apnea syndrome. The patient were randomized toreceive either the ApLab recording or the PSG diagnostic sleep study first. ThePSG study was conducted in a supervised sleep clinic. Patients were instructedin use of the ApLab device which was worn for one full night of sleep at home.

The Subjects were permitted to withdraw at any time from the trial for anyreason. Of the 30 patients enrolled, 24 successfully completed both aspects ofthe study.

The primary efficacy variable was the AHI score of the respiratory events,apnea and hypopnea. Several statistical analysis methods were used forassessing the agreement between AHI measured by the ApLab and PSG.Patients were allowed to discontinue at any time from the trial for any reason.

Number of patients planned and analyzed: Thirty (30) planned, twenty-four(24) analyzed. Six (6) did not complete both phases of the study. No adverseevents were recorded in this study.

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Diagnosis and main inclusion criteria: Patients with a diagnosis of obstructive sleepapnea syndrome or with a referring diagnosis of the obstructive sleep apneasyndrome.

1. Age greater than two years old.2. Either gender.3. Signed written informed consent prior to the initiation of any study related events.

Exclusion criteria: Any subject who in the investigator's opinion would have an unacceptable risk for

participation due to disease related criteria such as hypertension, cardiovasculardisease, or stroke.

Any subject who in the investigator's opinion would have an unacceptable risk forparticipation due to concomitant medical or psychiatric illness, or concomitantmedication.

Test Product: ApLab™ model 801D0020

Efficacy Criteria: The primary efficacy variable was the AHI score of the respiratoryevents, apnea and hypopnea. Scoring of apneas and hypopneas during standard PSG wasconverted to an AHI index for comparison to the results generated by the ApLab.

Safety Criteria: Safety assessments included monitoring for adverse effects throughoutthe study and vital signs assessment at the beginning of the study. Reports of adverseeffects and intercurrent illnesses were elicited by general questioning.

Safety was also assessed during the study by the use of a PSG.

Statistical Methods: Thirty (30) enrolled, twenty-four (24) analyzed. Sensitivity,Specificity, and Positive Predictive Value, with an AHI threshold of five (5) were 100%,67%, and 95% respectively. The AHI between ApLab and PSG was tested using Pearsonregression. A value of 0.883 was recorded indicating a strong positive relationship. Thepaired t-test technique, analyzing AHI between methods, did not indicate a statisticallysignificant difference between groups.

Safety Results: No adverse events were reported during this study.

Conclusions: The ApLab provided a reliable record of breathing during sleep. Study resultsdemonstrate that the ApLab can be used to screen for and aid in the diagnosis ofobstructive sleep apnea syndrome. The results of this study also demonstrate that theApLab was safe and well tolerated.Report Date: 5/13/2004

Sleep Apnea Background

Traditional Method of Diagnosis

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Obstructive Sleep Apnea Syndrome (OSAS) is a prevalent disease (1-3). Theconsequences of OSAS are wide spread and include cardiovascular disease such ashypertension, neurobehavioral disease such as excessive daytime sleepiness and death(4-13). There are enormous health care and hospitalization costs associated with thecondition (14-21). Recording multiple parameters during sleep, polysomnography (PSG)is the traditional method used for diagnosing OSAS. It is typically performed in a sleeplab, is labor intensive and is a relatively expensive procedure. The average cost is$1500-$2500. This suggests that low-cost, alternative approaches to diagnosis would beadvantageous.

Home Testing

Attempts to conduct full or partial PSGs in the home environment have reduced theamount of assessments made in the sleep lab (22-23). However, such approachescontinue to be relatively expensive and have a technical failure rate of approx 5-10%(24-26). Also, they tend to involve a diverse array of technologies that focus onparticular consequences of OSAS such as:

Oxygen De-saturation EKG Changes Respiratory Effort

Unfortunately these methods do not focus on disruptions in breathing which specificallydefine OSAS.

The ambulatory screening approaches used for the assessment of OSAS vary widely andrange from unattended full PSGs performed in patients’ homes (33-34) to single-channelpulse oximetry (27) and abbreviated channel screening devices that typically record (28-32):

Respiratory effort Airflow Body position Snoring sounds Pulse oximetry

AGC’s research has shown that continuously recorded, digitally acquired, single-channelpulse oximetry represents a well-evaluated approach (35-37). However some studieshave shown that a quick and inexpensive, continuous pulse oximetry can be affected byskin pigmentation, temperature, ventilation/perfusion mismatching, respiratoryalkalosis/acidosis, and specific response characteristics of the pulse oximeter (38-43).Some patients with OSAS, depending on their age and pulmonary status, maydesaturate very little. And this could lead to a substantial underestimation of thebreathing interruptions occurring during sleep.

Although promising, such simplified approaches may be confounded by individualdifferences in the extent of autonomic reactivity during sleep. As such, they represent

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indirect, “downstream” approaches to the measurement of OSAS.

Disease Assessment

Further understanding of OSAS pathophysiology is leading to new developments indisease assessment. Over the last decade, scientific appreciation has broadened with therecognition that obstruction of the upper airway represents a continuum of deterioration(44):

1. Snoring - indicating partial airway obstruction.2. Hypopnea - when the respiratory airflow may be diminished but still present.3. Sleep Apnea - when the airway occlusion is complete.

The key concept linking these conditions is Upper Airway Resistance Syndrome (UARS)(45-50). The gold standard definition of UARS within sleep requires invasiveendoesophageal monitoring. Exciting new research indicates that pressure changes inthe upper airway during inspiration in sleep can be reliably measured using a sensitivepressure transducer attached to a nasal cannula. Due to the quantitative measure ofpressure-based systems, the use of nasal/oral pressure as a tool for respiratorymonitoring is rapidly gaining acceptance as the superior method when compared tothermistors or thermocouples.

This is particularly important in the detection of partial airway obstruction such ashypopneas. One study showed that a pressure based system was effective indetermining 95 percent of respiratory events compared to 61 percent for thermistors.Other investigators have supported this approach (51-57).

The recognition and definition of such episodes of inspiratory flow limitation have led tounderstanding of the ubiquitous nature of sleep-related upper airway syndromes. Thishas greatly expanded the necessity for developing screening devices that allow foraccurate and reliable quantification of episodes of UARS during sleep.

REFERENCES1. Young T, Peppard P, Gottlieb, D. Epidemiology of Obstructive Sleep Apnea, APopulation Health Perspective. Am J Respir Crit Care Med Vol 165. pp 1217-1239, 2002

2. Young T, Palta M, Dempsey J, Skatrud J, Weber S, Badr S. The occurrence of sleep-disordered breathing among middle-aged adults. N Engl J Med 1993;328:1230-1235.

3. Young T, Shahar E, Nieto J, Redline S, Newman AB, Gottlieb DJ, Walsleben JA, Finn L,Enright P, Samet JM. Predictors of sleep-disordered breathing in community-dwellingadults. Arch Intern Med 2002;162:893-900.

4. Bixler EO, Vgontzas AN, Lin H, Ten Have T, Leiby BE, Vela-Bueno A, Kales A.Association of hypertension and sleep-disordered breathing. Arch Intern Med2000;160:2289-2295.

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5. Kim HC, Young T, Matthews CG, Weber SM, Woodard AR, Palta M. Sleep-disorderedbreathing and neuropsychological deficits. Am J Respir Crit Care Med 1997;156:1813-1819.

6. Nieto FJ, Young TB, Lind BK, Shahar E, Samet JM, Redline S, D’Agostino RB, NewmanAB, Lebowitz MD, Pickering TG. Association of sleep-disordered breathing, sleep apnea,and hypertension in a large community-based study. JAMA 2000;283:1829-1836.

7. Newman AB, Javier NF, Guidry U, Lind BK, Redline S, Shahar E, Pickering TG, QuanSF. Relation of sleep-disordered breathing to cardiovascular disease risk factors – theSleep Heart Health Study. Am J Epidemiol 2001;154:50-59.

8. Resnick HE, Redline S, Shahar E, Gilpin A, Newman A, Walter R, Ewy G, Howard B,Punjabi NM. Diabetes and sleep disturbances: findings from the Sleep Heart HealthStudy. Diabetes Care 2003;26:702-709.

9. Peppard PE, Young T, Palta M, Skatrud J. Prospective study of the associationbetween sleep-disordered breathing and hypertension. N Engl J Med 2000;342:1378-1384.

10. Morrell MJ, Finn L, Kim H, Peppard PE, Badr MS, Young T. Sleep fragmentation,awake blood pressure, and sleep-disordered breathing in a population-based study. AmJ Respir Crit Care Med 2000;162:2091-2096.

11. Young T, Peppard P, Palta M, Hla KM, Finn L, Morgan B, Skatrud J. Population-basedstudy of sleep-disordered breathing as a risk factor for hypertension. Arch Intern Med1997;157:1746-1752.

12. Shahar E, Whitney CW, Redline S, Lee ET, Newman AB, Nieto FJ, O’Connor GT,Boland LL, Schwartz JE, Samet JM. Sleep disordered breathing and cardiovasculardisease: cross-sectional results of the Sleep Heart Health Study. Am J Respir Crit CareMed 2001;163:19-25.

13. Young T, Peppard P. Sleep-disordered breathing and cardiovascular disease:epidemiological evidence for a relationship. Sleep 2000;23:S122-S126.

14. Otake K, Delaive K, Walld R, Manfreda J, Kryger MH. Cardiovascular medication usein patients with undiagnosed obstructive sleep apnoea. Thorax 2002;57:417-422.

15. Smith R, Ronald J, Delaive K, Walld R, Manfreda J, Kryger MH. What are ObstructiveSleep Apnea patients being treated for prior to this diagnosis? Chest 2002;121:164-172.

16. Ronald J, Delaive K, Roos L, Manfreda JH, Kryger MH. Obstructive Sleep Apneapatients use more health care resources ten years prior to diagnosis. Sleep Res Online1998;1:71-74.

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17. Kryger MH, Roos L, Delaive K, Walld R, Horrocks J. Utilization of health careservices in patients with severe Obstructive Sleep Apnea. Sleep 1996;19:S111-S116.

18 .Bahammam A, Delaive K, Ronald J, Manfreda J, Roos L, Kryger MH. Health careutilization in males with Obstructive Sleep Apnea syndrome two years after diagnosisand treatment. Sleep 1999;22:740-747.

19. Kapur VK, Redline S, Nieto FJ, Young TB, Newman AB, Henderson JA. Therelationship between chronically disrupted sleep and health care use. Sleep2002;25:289-296.

20. Ferber R, Millman R, Coppola M, Fleetham J, Murray CF, Iber C, McCall V, Nino-Murcia G, Pressman M, Sanders M, Strohl K, Votteri B, Williams A. Portable recording inthe assessment of Obstructive Sleep Apnea. Sleep 1994;17:378-392.

21. Ronald J, Delaive K, Roos L, Manfreda J, Bahammam A, Kryger M. Health CareUtilization in the 10 years prior to diagnosis in Obstructive Sleep Apnea patients. Sleep1999 Mar 15;22(2):225-229.

22. Chervin R, Murman D, Malow B, Totten V. Cost Utility of Three Approaches to theDiagnosis of Sleep Apnea: Polysomngraphy, Home testing, and Empirical Therapy. AnnInter. Med 1999;130:496-505

23. Standards of Practice Committee of the American Sleep Disorders Association.Practice parameters for the use of portable recording in the assessment of ObstructiveSleep Apnea. Sleep 1994;17:372-377.

24. Redline S, Sanders MH, Lind BK, Quan SF, Iber C, Gottlieb DJ, Bonekat WH,Rapoport DM, Smith PL, Kiley JP. Methods for obtaining and analyzing unattendedpolysomnography data for a multicenter study. Sleep 1998;21:759-767.

25. Kapur VK, Rapoport DM, Sanders MH, Enright P, Hill J, Iber C, Romaniuk J. Rates ofsensor loss in unattended home polysomnography: the influence of age, gender,obesity, and sleep-disordered breathing. Sleep 2000;23:682-688.

26. Nino-Murcia G, Bliwise DL, Keenan S, Dement WC. The assessment of a newtechnology for evaluating respiratory abnormalities in sleep: a comparison of thepolysomnogram and an ambulatory microprocessor. Int J Technol Assess Health Care1987;3:427-425..

27. George CF, Millar TW, Kryger MH. Identification and quantification of apneas bycomputer-based analysis of oxygen saturation. Am Rev Respir Dis 1988;137:1238-1240.

28. Reichert JA, Bloch DA, Cundiff E, Votteri BA. Comparison of the NovaSom QSG, anew sleep apnea home-diagnostic system and polysomnography. Sleep Medicine2003;4:213-218.

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29. Shochat T, Hadas, N, Kerkhofs M, Herchuelz A, Penzel T, Peter JH, Lavie P. TheSleep Strip: an apnoea screener for the early detection of sleep apnoea syndrome. EurRespir J 19:2002;121-126.

30. Claman D, Murr A, Trotter K. Clinical validation of the Bedbugg in detection ofObstructive Sleep Apnea. Otolaryngol Head Neck Surg 2001;125:227-230.

31. Redline S, Tosteson T, Boucher MA, Millman RP. Measurement of sleep-relatedbreathing disturbances in epidemiologic studies: assessment of the validity andreproducibility of a portable monitoring device. Chest 1991;100:1281-1286.

32. Emsellem HA, Corson WA, Rappaport BA, Hackett S, Smith LG, Hausfeld JN.Verification of sleep apnea using a portable sleep apnea screening device. South Med J1990;83:748-752.

33. Orr WC, Eiken T, Pegram V, Jones R, Rundell OH. A laboratory validation study of aportable system for remote recording of sleep-related respiratory disorders. Chest1994;105:160-162.

34. Portier F, Portmann A, Czernichow P, Vascaut L, Devin E, Benhamou D, Cuvelier A,Muir JF. Evaluation of home versus laboratory polysomnography in the diagnosis ofsleep apnea syndrome. Am J Respir Crit Care Med 2000;162:814-818.

35. Gyulay S, Olson LG, Hensley MJ, King MT, Murree Allen K, Saunders NA. Acomparison of clinical assessment and home oximetry in the diagnosis of ObstructiveSleep Apnea. Am Rev Respir Dis 1993;147:50-53.

36. Williams AJ, Yu G, Santiago S, Stein M. Screening for sleep apnea using pulseoximetry and a clinical score. Chest 1991;100:631-635.

37. Series F, Marc I, Cormier Y, La Forge, J. Utility of nocturnal home oximetry for casefinding in patients with suspected sleep apnea hypopnea syndrome. Ann Intern Med1993;119:449-453.

38. Chesson AL, Jr., Anderson WM, Walls RC, Bairnsfather LE. Assessment ofhypoxemia in patients with sleep disorders using saturation impairment time. Am RevRespir Dis 1993;148:1592-1598.

39. Yamashiro Y, Kryger MH. Nocturnal oximetry: is it a screening tool for sleepdisorders? Sleep 1995;18:167-171.

40. Decker MJ, Hoekje PL, Strohl KP. Ambulatory monitoring of arterial oxygensaturation. Chest 1989;95:717-722.

41. Cahan C, Decker MJ, Hoekje PL, Strohl KP. Agreement between noninvasiveoximetric values for oxygen saturation. Chest 1990;97:814-819.

42. Davila DG, Richards KC, Marshall BL, O’Sullivan PS, Gregory TG, Hernandez VJ, Rice

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SI. Oximeter performance: the influence of acquisition parameters. Chest2002;122:1654-1660.

43. Rebuck AS, Chapman KR. The P90 as a clinically relevant landmark on theoxyhemoglobin dissociation curve. Am Rev Respir Dis 1988;137:962-963.

44. Bliwise D, Jeffries B, Shulman D, Decker M. Validation of a Novel, Microprocessor-based Ambulatory Recording System for Evaluating Upper Airway Resistance duringSleep. GRA Grant Proposal, Nov. 2003

45. Hoffstein V, Mateika JH, Mateika S. Snoring and sleep architecture. Am Rev RespirDis 1991;143:92-96.

46. American Academy of Sleep Medicine Task Force. Sleep-related breathing disordersin adults: recommendations for syndrome definition and measurement techniques inclinical research: the report of an American Academy of Sleep Medicine Task Force.Sleep 1999;22:667-689.

47. Guilleminault C, Stoohs R, Clerk A, Cetel M, Maistros P. A cause of excessivedaytime sleepiness: the upper airway resistance syndrome. Chest 1993;104:781-787.

48. Guilleminault C, Stoohs R, Clerk A, Simmons J, Labanowski M. From ObstructiveSleep Apnea syndrome to upper airway resistance syndrome: consistency of daytimesleepiness. Sleep 1992;15:S13-S16.

49. Guilleminault C, Stoohs R, Duncan S. Snoring: daytime sleepiness in regular heavysnorers. Chest 1991;99:40-48.

50. Guilleminault C, Stoohs R, Shiomi T, Kushida C, Schnittger I. Upper airwayresistance syndrome, nocturnal blood pressure monitoring, and borderline hypertension.Chest 1996;109:901-908.

51. Norman RG, Ahmed MM, Walsleben JA, Rapoport DM. Detection of respiratoryevents during NPSG: nasal cannnula/pressure sensor versus thermistor. Sleep1997;20:1175-1184.

52. Ruhle KH, Fahrner A, Randerath W. Evaluating Oronasal Flow with Temperature(Thermistor) and Obstructive Pressure (Prongs). Pneumologie 2001 Jan; 55(1): 4-6

53. Norman G, Ahmed M, Walsleben J, Rapoport D. Detection of Respiratory EventsDuring NPSG: Nasal cannula/Pressure Sensor Versus Thermistor. Sleep 1997,20(12):1175-1184

54. Berg S, Haight JS, Yap J, Hoffstein V, Cole P. Comparison of Direct and IndirectMeasurements of Respiratory Airflow: Implications for Hypopneas. Sleep, 1997, 20 (1):60-64

55. Cunningham S, Shea S, White D. Comparison of Nasal Pressure and Thermistor

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Recordings in the Detection of Sleep-Disordered Breathing Events. Sleep Vol. 21,Supplement: 62

56. Hosselet J, Ayappa I, Norman RG, Krieger AC, Rapoport DM. Classification of Sleep-Disordered Breathing. Am J Respir Crit Care Med 2001 Feb; 163(2): 398-405

57. Ayappa I, Norman RG, Krieger AC, Rosen A, O’Malley RL, Rapoport DM. Non-invasivedetection of respiratory effort-related arousals (RERAs) by a nasal cannula/pressuretransducer system. Sleep 2000;23:763-771.

Interpreting ApLab™ Nasal Pressure Waveforms

One of the major advantages of the ApLab™ is that it provides a complete record ofnasal pressure respiration. This enables physicians to verify the AHI screening indexproduced by the ApLab™ Viewer. It also allows the physician to scan the respiratorywaveform for other components of sleep disordered breathing. For instance:

1. The physician can measure the duration of the apnea and hypopnea events. Thismight be useful since an event of a minute in duration would probably have moreconsequences than an event of 15 seconds.

2. The recording of UARS can demonstrate signs of SDB that are not reflected in theAHI.

3. The recording of RERA can demonstrate signs of SDB that are not reflected in theAHI.

4. Although not specifically designed to record snoring, the ApLab™ will record loud,low frequency snoring.

5. The ApLab™ can record other examples of SDB such as Cheyne-Stokesrespiration.

6. The ApLab™ is sensitive enough to record mouth breathing.

The following pages provide examples of the various SDB components. The first figureshows an example of a simultaneous recording of a PSG and the ApLab™. This providesthe reader with a base-line visual, giving the user an opportunity to familiarizehimself/herself with the appearance of a thermistor based PSG recording versus asimultaneous ApLab™ recording.

The next several figures provide examples of:

Normal breathing, Apneas, Hypopneas, UARS, RERA, Snoring, Cheyne-Stokes respiration, and Mouth breathing.

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Normal breathing is identified by a regular pattern that shows a rapidly risinginspiratory component. It often has a sharp peak that rapidly transitions into anexpiratory phase. The expiratory phase is less sharply defined than the inspiratoryphase. It often has a plateau near the baseline prior to the next inspiration.

Mouth breathing is shown by a reduced amplitude signal that is generally a squarewave pattern.

The difference between apneas and hypopneas is narrowly defined. The differentiationbetween them is often clinician dependent.

Upper Airway Resistance Syndrome can be shown as a generally square wavepattern. The normal inspiratory pressure curve is flattened due to increased inspiratoryresistance.

Respiratory effort related arousals are identified through intermittent periods ofrelatively high amplitudes separated by normal or reduced amplitude signal. Althoughexamples of RERA were recorded during clinical studies, no formal analysis was done.Further investigations in this area are warranted.

Snoring can be detected by very high frequency spikes of pressure.

Cheyne-Stokes respiration can be identified by detecting periods of high magnitudepressure signals that are separated by low magnitude pressure signals that wax andwane. A period of apnea often follows.

Often, combinations of the above events will occur closely to each other. This only helpsconfirm the theory that SDB is a continuity of events ranging from complete apnea tosnoring.

There may be rare cases where the nasal cannula becomes displaced. There is usuallyenough data recorded to analyze the recording. It may be necessary to increase themagnification of the signal by using the ApLab™ Viewer.

These images are representative examples and are not the only way in which the SDBmay be recorded. As the field of nasal pressure respiratory measurement grows, it maybe that each individual’s respiratory pattern is as unique as a fingerprint.

Sleep Apnea Example Screen Shots

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Apnea Screen Shot

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Hypopnea Screen Shot

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Respiratory Effort Related Arousals Screen Shot

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Upper Airway Resistance Screen Shot

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Snoring Screen Shot

Articles

Links

PSG vs. the SleepStrip

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=16890080&query_hl=12&itool=pubmed_docsum

Do one in four have OSA?

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=16963675&query_hl=17 &itool=pubmed_docsum

Sleep apnea and kids

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=16735907&query_hl=17 &itool=pubmed_DocSum

Home studies vs. PSG


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A PSG for all stroke patients?


Screening for sleep apnea


Professional drivers and OSA


ADHD and sleep apnea


Pharmacies and sleep apnea


UARS outcomes


The eye and sleep apnea


Obese kids and sleep apnea

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=16428369&query_hl=17&itool=pubmed_DocSum

OSA and surgery


Erectile dysfunction and OSA


Tooth loss and sleep apnea


Congestive heart failure and OSA


Sleep Apnea and psychiatry

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=16335330&query_hl=17

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&itool=pubmed_DocSum

Treating OSA saves money


Losing weight treats sleep apnea


Frequency analysis of breath sounds and OSA


Advances in SDB


Pediatrics and OSA


ARES vs. PSG in sleep apnea


Primary care and sleep apnea


Articles: Table of ContentsAssessment of inspiratory flow limitation in children with sleep-disordered breathing by anasal cannula pressure transducer system.Serebrisky D, Cordero R, Mandeli J, Kattan M, Lamm C.

Detection of respiratory events during NPSG: nasal cannula/pressure sensor versusthermistor.Norman RG, Ahmed MM, Walsleben JA, Rapoport DM.

Detection of upper airway resistance syndrome using a nasal cannula/pressuretransducer.Epstein MD, Chicoine SA, Hanumara RC.

Diagnosis of sleep apnea by automatic analysis of nasal pressure and forced oscillation

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impedance.Steltner H, Staats R, Timmer J, Vogel M, Guttmann J, Matthys H, Christian Virchow J.

[Evaluating oronasal flow with temperature (thermistor) and obstructive pressure(prongs)][Article in German]Ruhle KH, Fahrner A, Randerath W.

Nasal pressure recording in the diagnosis of sleep apnoea hypopnoea syndrome.Series F, Marc I.

Nasal prongs in the detection of sleep-related disordered breathing in the sleepapnoea/hypopnoea syndrome.Ballester E, Badia JR, Hernandez L, Farre R, Navajas D, Montserrat JM.

Non-Invasive detection of respiratory effort-related arousals (REras) by a nasalcannula/pressure transducer system.Ayappa I, Norman RG, Krieger AC, Rosen A, O'malley RL, Rapoport DM.

Two-point palatal discrimination in patients with upper airway resistance syndrome,obstructive sleep apnea syndrome, and normal control subjects.Guilleminault C, Li K, Chen NH, Poyares D.

Use of nasal cannula for detecting sleep apneas and hypopneas in infants and children.Trang H, Leske V, Gaultier C.

Validation of nasal pressure for the identification of apneas/hypopneas during sleep.Heitman SJ, Atkar RS, Hajduk EA, Wanner RA, Flemons WW.

Anaesthetic management of patients with sleep apnoea syndrome.Boushra NN.

Induction of anesthesia for a patient with sleep apnea syndrome][Article in German]Ostermeier AM, Hofmann-Kiefer K, Schwender D.

Anesthetic management of obstructive sleep apnea patients.Connolly LA

The upper airway during anaesthesia.Hillman DR, Platt PR, Eastwood PR.

Sleep apnea syndrome in patients undergoing total joint arthroplasty.Parikh SN, Stuchin SA, Maca C, Fallar E, Steiger D.

Obstructive sleep apnoea syndrome in children.

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Warwick JP, Mason DG.

Anesthetic management of a patient with obstructive sleep apnea syndrome and difficultairway access.Biro P, Kaplan V, Bloch KE.

Sleep apnea syndromes in adults and its anesthesiologic repercussions][Article in Spanish]Vazquez-Gutierrez T, Sanchez-Valderrabanos J, Caba-Barrientos F.

Perioperative managements of a mentally retarded child with obstructive sleep apneasyndrome for adeno-tonsillectomy][Article in Japanese]Oohata H, Takada M, Ishizawa Y, Akamatsu S, Shimonaka H, Dohi S.

Anaesthesia and sleep apnoea.Loadsman JA, Hillman DR.

Perioperative complications and risk factors in the surgical treatment of obstructive sleepapnea syndrome.Esclamado RM, Glenn MG, McCulloch TM, Cummings CW.

Nasal continuous positive airway pressure in the perioperative management of patientswith obstructive sleep apnea submitted to surgery.Rennotte MT, Baele P, Aubert G, Rodenstein DO.

The diagnosis of obstructive sleep apnea as a risk factor for unanticipated admissions inoutpatient surgery.Sabers C, Plevak DJ, Schroeder DR, Warner DO.

Oral appliances for the treatment of snoring and obstructive sleep apnea: a review.Schmidt-Nowara W, Lowe A, Wiegand L, Cartwright R, Perez-Guerra F, Menn S.

Oral appliances for the management of snoring and obstructive sleep apnoea.Bennett LS, Davies RJ, Stradling JR.

A short-term controlled trial of an adjustable oral appliance for the treatment of mild tomoderate obstructive sleep apnoea.Ferguson KA, Ono T, Lowe AA, al-Majed S, Love LL, Fleetham JA.

A randomized crossover study of an oral appliance vs nasal-continuous positive airwaypressure in the treatment of mild-moderate obstructive sleep apnea.Ferguson KA, Ono T, Lowe AA, Keenan SP, Fleetham JA.

Articles

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Nasal Pressure Transducer Technology

Pediatr Pulmonol. 2002 May;33(5):380-7.

Assessment of inspiratory flow limitation in children with sleep-disorderedbreathing by a nasal cannula pressure transducer system.Serebrisky D, Cordero R, Mandeli J, Kattan M, Lamm C.Department of Pediatrics, Mount Sinai School of Medicine, New York, New York10029, USA.

A nasal cannula pressure transducer system identifies inspiratory flow limitation andincreased upper airway resistance in adults with sleep-disordered breathing (SDB). Thepurpose of this study was to evaluate whether nasal cannula pressure (NCP) detectsapneas and hypopneas as well as additional flow-limited events associated withincreased airway resistance in children.

We studied NCP in 47 patients (ages 2-14 years) referred for SDB to a university-basedsleep disorders program during nocturnal polysomnography (NPSG). During NPSG,airflow was assessed simultaneously by thermistor and NCP. There was a highcorrelation between apneas assessed by thermistor (T) and NCP (r = 0.90, P < 0.0001),and for hypopneas using these two methods (r = 0.94, P = 0.0001). Respiratory drivingpressure was indirectly measured with an esophageal pressure catheter. Flow-limited(flattened) NCP waves were associated with significantly higher driving pressure,indicating elevated upper airway resistance, compared to nonflow-limited (rounded)waves during nonrapid eye movement (NREM) (P = 0.05) and rapid eye movement(REM) (P = 0.01) sleep. Patients were classified as either having obstructive sleep apneasyndrome (OSAS) or primary snoring, based on standard NPSG criteria. NCP identifiedadditional respiratory events with a flattened contour (FC) not detected by thermistor.

CONCLUSION: NCP is a noninvasive device that identifies obstructive apneas andhypopneas as well as additional respiratory events associated with flow limitation inchildren.

Sleep. 1997 Dec;20(12):1175-84.Detection of respiratory events during NPSG: nasal cannula/pressure sensorversus thermistor.Norman RG, Ahmed MM, Walsleben JA, Rapoport DM.Division of Pulmonary and Critical Care Medicine, New York University MedicalCenter, New York 10016, USA.

Recording of respiratory airflow is an integral part of polysomnography (NPSG). It isconventionally monitored with a thermistor that measures temperature as a surrogate offlow. The subjectivity of interpreting hypopnea from this signal has prompted us tomeasure nasal airflow directly with a simple pneumotachograph consisting of a standardnasal cannula connected to a 2-cm H2O pressure transducer.

We manually analyzed respiratory events using simultaneous thermistor and nasal

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cannula in 11 patients with obstructive sleep apnea syndrome (OSAS) and 9 with upperairway resistance syndrome (UARS). Definite events were scored separately for eachsignal when amplitude was <50% for >10 seconds. Events were also scored on thenasal cannula signal when the flattened shape of the signal suggested flow limitation,and these were tabulated separately. Definite events in one signal were tabulated bywhether the other signal showed a definite event or not. In addition, nasal cannulaevents were compared to a more liberal thermistor criterion (any change in the signalfor > or = 2 breaths).

Visually, events were more easily recognized on the nasal cannula signal than on thethermistor signal. In OSAS, 1,873 definite thermistor events were detected. Of these,99.1% were detected by nasal cannula, and 0.9% were missed. Of 3,541 definite nasalcannula events, 51.9% were detected by definite thermistor criteria; 75.0% weredetected by liberal thermistor criteria; 25.0% were missed.In UARS, 123 definite thermistor events were detected. Of these, 89.4% were detectedby nasal cannula and 10.6% were missed. Nine hundred and three nasal cannula eventswere detected. However, only 17.2% of these were detected by definite thermistorcriteria; 38.6% were detected by liberal thermistor criteria; 61.4% were completelyundetected by thermistor. When events identified on the nasal cannula by flow limitationalone were excluded, the thermistor detected 30.1% of events by definite criteria and78.6% by liberal criteria, still leaving 21.4% completely undetected by the thermistor.

CONCLUSION: We conclude that the nasal cannula reliably detects respiratory eventsseen by thermistor. Additional events (including some characterized only by flowlimitation) that help define the UARS, were recognized by nasal cannula but oftencompletely missed by thermistor. We propose that respiratory monitoring during NPSGwith nasal cannula significantly improves event detection and classification over thatwith thermistor.

Chest. 2000 Apr;117(4):1073-7.Detection of upper airway resistance syndrome using a nasal cannula/pressuretransducer.Epstein MD, Chicoine SA, Hanumara RC.Department of Medicine and Sleep Disorders Center, Roger Williams MedicalCenter, Providence, RI, USA.

STUDY OBJECTIVES: To determine the diagnostic utility of a nasal cannula/pressuretransducer (NC), in comparison to thermistor (TH), during routine, clinical nocturnalpolysomnography (NPSG).DESIGN: We analyzed the respiratory arousal index (RAI) using TH (RAI-TH) or NC(RAI-NC) in patients with suspected sleep-disordered breathing (SDB).SETTING: Sleep disorders center of a university-affiliated teaching hospital.PATIENTS: Fifty consecutive, nonselected patients referred for evaluation of suspectedSDB. Measurements and results: Twenty patients were found to have obstructive sleepapnea/hypopnea syndrome (OSA), 25 had upper airway resistance syndrome (UARS),and 5 had primary snoring (PS). Mean RAI-NC was greater than the mean RAI-TH by25%, 302%, and 500% in OSA, UARS, and PS, respectively. RAI-NC was >/= 14 (mean,25.2) in UARS and < 14 (mean, 9) in PS. Mean RAI-TH was 8.4 in UARS and 1.8 in PS,

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with significant overlap between the two groups.

CONCLUSIONS: NC is more sensitive than TH in detecting respiratory events duringNPSG and may represent a simple, objective means to identify UARS among patientswith a range of SDB.

Am J Respir Crit Care Med. 2002 Apr 1;165(7):940-4.Diagnosis of sleep apnea by automatic analysis of nasal pressure and forcedoscillation impedance.Steltner H, Staats R, Timmer J, Vogel M, Guttmann J, Matthys H, ChristianVirchow J.Center for Data Analysis and Modeling, University of Freiburg, Freiburg,Germany. [email protected]

Detecting and differentiating central and obstructive respiratory events is an importantaspect of the diagnosis of sleep-related breathing disorders with respect to the choice ofan appropriate treatment. The purpose of this study was to evaluate the performance ofa new algorithm for automated detection and classification of apneas and hypopneas,compared with visual analysis of standard polysomnographic signals.

The algorithm is based on time series analysis of nasal mask pressure and a forcedoscillation signal related to mechanical respiratory input impedance, measured at afrequency of 20 Hz throughout the night. The method was applied to all-nightmeasurements on 19 subjects. Two experts in sleep medicine independently scored thecorresponding simultaneously recorded polysomnographic signals. Evaluating theagreement between two scorers by a weighted kappa statistic on a second-by-secondbasis, we found that inter-expert variability and the discrepancy between automaticanalysis and visual analysis performed by an expert were not significantly different.

CONCLUSION: Implementation of this algorithm in a device for home monitoring ofbreathing during sleep might aid in the differential diagnosis of sleep-related breathingdisorders and/or as a means for follow-up and treatment control.

Pneumologie. 2001 Jan;55(1):4-6.[Evaluating oronasal flow with temperature (thermistor) and obstructivepressure (prongs)][Article in German]Ruhle KH, Fahrner A, Randerath W.Klinik fur Pneumologie, Klinik Ambrock, Universitat Witten/Herdecke, Hagen.

The measurement of oronasal flow during sleep studies using thermistors isinternationally well accepted. As an alternative the possibility exists to measure thepressure at the nose by means of nasal prongs.

Our objective was to compare and evaluate the methods to detect respiratory events inclinical routine, namely O2-saturation by pulse oxymetry oronasal flow by thermistorsthoraco-abdominal effort by belts oronasal flow by prongs, 8 consecutive patientssuspected of sleep apnoea syndrome (7 m, 1 f), mean age 56.5 +/- 9.5 years, height

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173 +/- 6.4 cm, BMI 28.7 +/- 2.6 kg/m2, Epworth sleepiness scale score 9.1 +/- 3.2,AHI 24.9 +/- 13.7 h-1, lowest SaO2 86 +/- 4.9%, were examined.

Between nose and mouth we fixed an oronasal 3-point thermistor and oronasal prongs(2 openings at the mouth and 2 openings at the mouth applying a common tube).During breathing the resulting pressure was registered with a pressure transducerparallel to the signal of the thermistors and the other polysomnographic data. Wedefined a respiratory event if at least one of the 4 signals met the criteria of arespiratory disturbance (for exact definitions see method). The detection rate of the 4signals was calculated in relation to the sum of all events. Of the 1824 events (100%)only 52.3% were detected by an O2-desaturation of more than 4%, but 61.0% bythermistors. An acceptable detection rate was found measuring effort with 83.4%, onlynasal prongs detected 95.1% of all events.

CONCLUSION: We conclude that with regard to the detection rate of respiratory eventsthe measurement of pressure by nasal prongs is superior to the use of thermistors.

Thorax. 1999 Jun;54(6):506-10.Nasal pressure recording in the diagnosis of sleep apnoea hypopnoeasyndrome.Series F, Marc I.Unite de Recherche, Centre de Pneumologie de l'Hopital Laval, Universite Laval,Quebec, Canada.

BACKGROUND: Nasal pressure tracing is now being used to measure breathing inambulatory screening devices for sleep apnoea but it has not been compared with othermethods of assessment.

METHODS: Sleep induced breathing disorders were scored by three different methods ofanalysis (thermistry, inductive plethysmography, and nasal pressure tracing) in 193consecutive patients referred to our sleep laboratory. With the conventional thermistrymethod an apnoea was defined as the absence of oronasal flow on the thermistor signalfor >/=10 s and a hypopnoea as a 50% decrease in the sum signal of inductiveplethysmography tracing for >/=10 s associated with an arousal and/or a 2% decreasein SaO2. Nasal pressure was measured via nasal prongs connected to a pressuretransducer. Using the thermistor signal alone, a hypopnoea was defined as a 50%decrease in the signal for >/=10 s associated with an arousal and/or a 2% decrease inSaO2. A similar definition of apnoea and hypopnoea was used for nasal pressure, the fallin pressure being substituted for the thermistor reading.

RESULTS: Impaired nasal ventilation prevented adequate measurements of nasalpressure in 9% of subjects. According to the conventional method of interpretation 107subjects were identified as having the sleep apnoea hypopnoea syndrome (SAHS). Theapnoea + hypopnoea index (AHI) was significantly lower using the thermistry methodthan with conventional analysis (mean difference -4.3/h, 95% CI -5.3 to -3.2, p<10(-4)); 39% of conventional hypopnoeic events were scored as apnoeas using nasalpressure scoring. Apnoeic and hypopnoeic events could also be observed without anychange in thermistor and sum Respitrace signals that resumed with the occurrence of

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arousals or awakenings. The AHI was significantly higher with nasal pressure scoringthan with the conventional method (mean difference 4.5, 95% CI 3.4 to 5.6, p<10(-4)).The mean difference in apnoea index between conventional and nasal pressure scoringwas -7.5/h (95% CI -8.9 to -6.1). In the 78 patients who did not have SAHS accordingto the conventional method of analysis there was a significant positive relationshipbetween the arousal index and AHI measured by nasal pressure tracing (R = 0.51,p<10(-4)). Seventeen of the 78 patients had an AHI of >15/h by the nasal pressuremethod of analysis.

CONCLUSIONS: Nasal pressure recording provides a simple and reliable measurement ofnocturnal breathing abnormalities and may identify breathing abnormalities associatedwith arousals that are missed by other diagnostic methods.

Eur Respir J. 1998 Apr;11(4):880-3.Nasal prongs in the detection of sleep-related disordered breathing in the sleepapnoea/hypopnoea syndrome.Ballester E, Badia JR, Hernandez L, Farre R, Navajas D, Montserrat JM.Departament de Medicina, Hospital Clinic, Universitat de Barcelona, Spain.

Conventional systems to monitor oronasal flow in sleep studies have traditionally reliedon a thermistor signal. Our study was designed to verify whether nasal prongs (NP)connected to a pressure transducer could improve respiratory events detection inpatients with sleep apnoea/hypopnoea syndrome (SAHS) compared to traditionalsystems. Sleep episodes from a 2 h conventional polysomnographic record plus NPsignal obtained at random from eight patients (age: mean(+/-SD) 53(+/-12) yrs; bodymass index (BMI): 29(+/-6) kg x m(-2); apnoea/hypopnoea index (AHI): 27(+/-20)events x h(-1)) were identified and used for analysis. An abnormal change in the patternof any of the respiratory or neurological variables occurring during the observationperiod was defined as an episode.

Each episode was registered and scored with concomitant scoring of the remainingvariables. According to the episode definition three different profiles were established: 1)periods of reduction of ventilation in either variable without an arousal or cyclicaldesaturation, named nonpathological episode (NPE); 2) an idiopathic or nonrespiratoryarousal (IA); and 3) a true respiratory event (TRE) defined as reduction or absence offlow demonstrated by either thermistor, thoraco-abdominal bands or NP accompanied bycyclical desaturation and/or arousal. For each TRE, its detection by thermistor, thoraco-abdominal bands or NP was established. A total of 877 sleep episodes were observed(42 NPE, 30 IA and 805 TRE). When compared to single or combined thermistor andbands approach, NP had the highest respiratory events detection rate, 779 (96.8%)versus 673 events (83.6%), respectively. Detection of respiratory-related arousals wasalso improved by NP and only 3% could account for mouth breathing respiration.

CONCLUSION: It is concluded that nasal prongs improve the detection of respiratoryevents in patients with sleep respiratory disorders.

Sleep. 2000 Sep 15;23(6):763-71.Non-Invasive detection of respiratory effort-related arousals (REras) by a nasal

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cannula/pressure transducer system.Ayappa I, Norman RG, Krieger AC, Rosen A, O'malley RL, Rapoport DM.NYU School of Medicine, New York, NY USA.

STUDY OBJECTIVES: The published AASM guidelines approve use of a nasalcannula/pressure transducer to detect apneas/hypopneas, but require esophagealmanometry for Respiratory Effort-Related Arousals (RERAs). However, esophagealmanometry may be poorly tolerated by many subjects. We have shown that the shapeof the inspiratory flow signal from a nasal cannula identifies flow limitation and elevatedupper-airway resistance. This study tests the hypothesis that detection of flow limitationevents using the nasal cannula provides a non-invasive means to identify RERAs.

DESIGN: N/A SETTING: N/A PATIENTS: 10 UARS/OSAS and 5 normal subjects

INTERVENTIONS: N/A MEASUREMENTS AND RESULTS: All subjects underwent fullNPSG. Two scorers identified events from the nasal cannula signal as apneas,hypopneas, and flow limitation events. Two additional scorers identified events fromesophageal manometry. Arousals were scored in a separate pass. Interscorer reliabilityand intersignal agreement were assessed both without and with regard to arousal. Thetotal number of respiratory events identified by the two scorers of the nasal cannula wassimilar with an Intraclass Correlation (ICC) =0.96, and was essentially identical to theagreement for the two scorers of esophageal manometry (ICC=0.96). There was goodagreement between the number of events detected by the two techniques with a slightbias towards the nasal cannula (4.5 events/hr). There was no statistically significantdifference (bias 0.9/hr, 95%CI -0.3-2.0) between the number of nasal cannula flowlimitation events terminated by arousal and manometry events terminated by arousal(RERAs).

CONCLUSION: The nasal cannula/pressure transducer provides a non-invasivereproducible detector of all events in sleep disordered breathing; in particular, it detectsthe same events as esophageal manometry (RERAs).

Chest. 2002 Sep;122(3):866-70.Two-point palatal discrimination in patients with upper airway resistancesyndrome, obstructive sleep apnea syndrome, and normal control subjects.Guilleminault C, Li K, Chen NH, Poyares D.Stanford University Sleep Disorders Clinic, CA 94305, USA. [email protected]

STUDY OBJECTIVE: To compare the results of a two-point palatal discriminationresponse in normal subjects (n = 15), patients with obstructive sleep apnea syndrome(OSAS) [n = 15], and patients with upper airway resistance syndrome (UARS) [n = 15]matched for age, sex, and body mass index.

DESIGN: Comparison study of three subject groups.

SETTING: A sleep-disorders clinic.

SUBJECTS: Participants were selected based on clinical questionnaire, clinical evaluation,

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and polysomnography.

INTERVENTION: Polysomnography involving measurement of flow limitation with a nasalcannula pressure transducer system and of respiratory effort with esophageal pressurewas performed in order to recognize the presence, absence, and types of sleep-disordered breathing. The 45 subjects were submitted to a two-point palataldiscrimination study during wakefulness performed by an investigator blinded to thepolysomnogram results.

RESULTS: Patients with OSAS had a clear impairment of their palatal sensory input witha significant decrement in two-point discrimination, but patients with UARS and normalcontrol subjects had similar responses. Patients with UARS exhibited at least intermittentsnoring in most cases.

CONCLUSION: The normal responses seen in patients with UARS indicate that thesepatients are more capable of transmitting sensory inputs than patients with OSAS. Thismay be one element explaining the difference in arousal response previouslydocumented in UARS compared to OSAS.

Am J Respir Crit Care Med. 2002 Aug 15;166(4):464-8.Use of nasal cannula for detecting sleep apneas and hypopneas in infants andchildren.Trang H, Leske V, Gaultier C.Service de Physiologie, Hopital Robert Debre, Universite Paris VII, INSERME9935, 48 boulevard Serurier, 75019 Paris, France. [email protected]

We evaluated tolerance of nasal cannula (NC) by 14 infants (median age, 2.6 months)and 16 children (median age, 5.5 years) with suspected obstructive sleep apneasyndrome and compared the efficacy of the NC with that of a nasobuccal thermistor indetecting obstructive apneas (OA) and obstructive hypopneas (OH) on polysomnographytraces. The relationship between cannula flow and esophageal pressure was assessed insix patients. Time spent with an uninterpretable flow signal was longer when using acannula than when using a thermistor in infants (p < 0.05) and children (p < 0.01), andit was longer in the younger patients (p < 0.05). Among the 650 OA-OH detected byeither method, only 38% were detected by both, and 58% were detected by the cannulaand missed by the thermistor, so that the apnea-hypopnea index was higher withcannula than with thermistor in each age group (p < 0.01). More hypopneas thanapneas were detected by the cannula and missed by the thermistor (p < 0.001). Out-of-phase thoracic and abdominal motions and/or changes in the end-tidal CO(2) signalshape were associated with 86% of OH identified by cannula. In the six patients whoseesophageal pressure was measured, all respiratory events identified using a cannulawere associated with increased "airway resistance."

CONCLUSION: Thus, the NC is more likely than the thermistor to detect OA and OH ininfants and children, and this superiority is particularly marked for hypopneas.

Am J Respir Crit Care Med. 2002 Aug 1;166(3):386-91.

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Validation of nasal pressure for the identification of apneas/hypopneas duringsleep.Heitman SJ, Atkar RS, Hajduk EA, Wanner RA, Flemons WW.Department of Medicine, Foothills Hospital/University of Calgary, 1403 29thStreet NW, Calgary, Alberta, T2N 2T9 Canada.

The reference standard for identifying apneas and hypopneas is a pneumotachograph,but using this can disrupt sleep. Nasal airflow estimation by measuring nasal pressurevia nasal prongs is better tolerated by patients. However, nasal pressure has not beenvalidated, using an event-by-event analysis, for detecting apneas/hypopneas duringsleep. Eleven patients undergoing polysomnography wore a nasal mask capable ofmeasuring nasal airflow (via pneumotachograph) and nasal pressure simultaneously.Each study was screened for respiratory disturbances, and from these 550 wererandomly selected and blindly scored as an apnea/hypopnea or no event each using thepneumotachograph, nasal pressure, square root nasal pressure, and respiratoryinductance sum signals independently. Agreement was measured using Cohen's kappastatistic. Intermeasurement agreements between the pneumotachograph and nasalpressure, square root nasal pressure, and respiratory inductance plethysmography sumwere 0.76, 0.73, and 0.50, respectively. Inter- and intrarater agreements were,respectively, 0.68 and 0.60 for the pneumotachograph, 0.66 and 0.82 for nasalpressure, 0.61 and 0.78 for square root nasal pressure, and 0.47 and 0.76 forrespiratory inductance plethysmography sum.CONCLUSION: These results indicate that nasal pressure has excellent agreementcompared with a pneumotachograph and very good inter-/intrarater agreement. Squareroot transformation of the nasal pressure signal does not improve these levels ofagreement, indicating that it is unnecessary in routine clinical practice for scoringapneas/hypopneas.

Articles Anesthesia & Sleep Apnea

Can J Anaesth. 1996 Jun;43(6):599-616.Erratum in: Can J Anaesth 1996 Nov;43(11):1184.Anaesthetic management of patients with sleep apnoea syndrome.Boushra NN.Department of Anaesthesia, Al-Salam Teaching Hospital, Cairo, Egypt.

PURPOSE: Sleep apnoea syndrome (SAS) is a relatively common, potentially fatal,disorder. Patients with SAS exhibit repetitive, often prolonged episodes of apnoea duringsleep, with serious nocturnal and diurnal physiologic derangements. Several anecdotalreports and clinical studies have documented anaesthetic-related occurrence of fatal andnear-fatal respiratory complications in these patients. The purpose of this article is tooutline the potential problems encountered in anaesthetic management of adult SASpatients, and to suggest a practical approach for anaesthesia both for incidental andspecific procedures.

PRINCIPAL FINDINGS: SASs have many implications for the anaesthetist. First, SASpatients are exquisitely sensitive to all central depressant drugs, with upper airway

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obstruction or respiratory arrest occurring even with minimal doses. Thus sedative andopioid premedication should be omitted as should the intra and postoperative use ofopioids be limited or avoided. All anaesthetic drugs should be administered by titrationto desired effect, preferably using short-acting drugs. When feasible, continuous regionalanaesthesia using a catheter is the technique of choice. Where possible nonopioidanalgesics or local anaesthetics should be used for postoperative analgesia.Perioperative monitoring for apnoea, desaturation, and dysrhythmias is essential.Secondly, SAS patients have a potentially difficult airway. Awake intubation is the safestapproach to airway control. Extubation should only be tried in the fully conscious patientwith intact upper airway function and under controlled situations. Thirdly, thecardiorespiratory complication of SAS and the presence of associated diseases canadversely influence anaesthetic management.

CONCLUSION: Perioperative risks attending SAS patients emphasize the importance oftheir detection, perioperative evaluation and planning.

Anaesthesist. 2000 Apr;49(4):317-20.[Induction of anesthesia for a patient with sleep apnea syndrome][Article in German]Ostermeier AM, Hofmann-Kiefer K, Schwender D.Klinik fur Anaesthesiologie, Ludwig-Maximilians-Universitat [email protected]

Based on a case report, we offer brief guidelines on the perioperative management ofpatients with Sleep-Apnea-Syndrome (SAS) who present with a high incidence of adifficult airway and a high risk of respiratory depression during the perioperative period.A 39 year old male patient with a body mass index of 34.22 kg/m2 and receivingcontinuous-positive-airway-pressure-(CPAP) therapy for known SAS was scheduled forelective plastic surgery.

After induction of anaesthesia and direct laryngoscopy no adequate airway could beestablished and the patient became hypoxic, hypercapnic and developed hypotensionand bradycardia. With the use of a laryngeal mask airway the patient was stabilized anddid not show neurologic sequale after immediate awakening. The following fiberopticintubation of the awake patient, still showing tendency of upper airway obstruction,confirmed the difficult anatomical structures. The subsequent general anesthesia wasuneventful. The patient received CPAP therapy and was monitored during the firstpostoperative night in the Intensive Care Unit. He made an uneventful recovery.

He was advised to have regional anaesthesia or planned fiberoptic intubation, wherepossible, in the case of further anesthetic intervention. SAS has major implications forthe anaesthesiologist and whenever patients exhibiting the high risk factors (obesity,male sex, history of intense snoring, impaired daytime performance, nonrefreshingdaytime naps) are presented for surgery this condition should be considered. Electivesurgery should be postponed until after adequate examination and treatment whennecessary. Patients with SAS should always be suspected of having cardiopulmonarydysfunctions such as hypertension, cardiac dysrhythmia or cor pulmonale. It is mostimportant to avoid sedative premedication, to initiate CPAP therapy preoperatively, to

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encourage regional anaesthesia if possible and to ensure close monitoring over thecomplete perioperative period. Planned fiberoptic intubation, preferably with surgicalpersonnel available for an emergency airway, is a safe method for the induction ofanaesthesia.

Postoperatively, patients are at high risk from respiratory depression, even in the awakestate. Postoperative opioid analgesia, no matter what route, should only be given underclose monitoring. Independently of regional or general anaesthesia there is an increasedrisk of respiratory depression in the middle of the first postoperative week, suspected tobe caused by the catching up on lost REM-sleep, due to shifts in the normal sleeppattern during the first postoperative days.

J Clin Anesth. 1991 Nov-Dec;3(6):461-9.Anesthetic management of obstructive sleep apnea patients.Connolly LA.Department of Anesthesiology, Medical College of Wisconsin, Milwaukee 53226.

Presented in an illustrative case report and a review of the anesthetic management ofobstructive sleep apnea patients. Preoperative evaluation should include a thoroughairway evaluation and a comprehensive cardiovascular and pulmonary evaluation. Withpolysomnography, identification of the severity of sleep apnea can be idenified. Althoughsleep centers vary in their definitions, severe obstructive sleep apnea is diagnosed if thepatient demonstrates an apnea index greater than 70 and an oxygen (O2) desaturationless than 80% with cardiovascular sequelae. Severe sleep apnea patients are at extremerisk for general anesthesia. These risks should be discussed preoperatively with thepatient. Unsupervised preoperative sedation should be avoided because of the extremesensitivity of these patients to sedatives and airway obstruction. Intraoperativemanagement of the obstructive sleep apnea patient varies depending on the severity ofthe sleep apnea. Invasive monitoring may be necessary if the patient demonstratesevidence of cardiopulmonary dysfunction. With the assistance of the otolaryngologist,the anesthesiologist can formulate an approach to establishing an airway. Intraoperativeopioids and sedatives should be limited. The recovery of the sleep apnea patient isextremely important and is the time when most airway emergencies occur. Extubation ofthe patient should occur when appropriate surgical personnel and equipment areavailable in case of an airway emergency. Steroids may be used to decrease the amountof airway swelling. Supplemental O2 should be used in patients who demonstratedesaturation. Opioids and sedatives should be avoided, as should other drugs that havecentral and sedating effects. Postoperative pain is effectively controlled withacetaminophen and topical anesthetic sprays. Postoperative monitoring for apnea,desaturation, and dysrhythmias is a necessity in sleep apnea patients.

Publication Types: Case Reports Review Review, Tutorial

Br J Anaesth. 2003 Jul;91(1):31-9.

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The upper airway during anaesthesia.Hillman DR, Platt PR, Eastwood PR.West Australian Sleep Disorders Research Institute, Department of PulmonaryPhysiology, Nedlands 6009, Western Australia. [email protected]

Upper airway obstruction is common during both anaesthesia and sleep. Obstruction iscaused by loss of muscle tone present in the awake state. The velopharynx, aparticularly narrow segment, is especially predisposed to obstruction in both states.Patients with a tendency to upper airway obstruction during sleep are vulnerable duringanaesthesia and sedation. Loss of wakefulness is compounded by depression of airwaymuscle activity by the agents, and depression of the ability to arouse, so they cannotrespond adequately to asphyxia. Identifying the patient at risk is vital. Previousanaesthetic history and investigations of the upper airway are helpful, and a history ofupper airway compromise during sleep (snoring, obstructive apnoeas) should be sought.Beyond these, risk identification is essentially a search for factors that narrow theairway. These include obesity, maxillary hypoplasia, mandibular retrusion, bulbar muscleweakness and specific obstructive lesions such as nasal obstruction or adenotonsillarhypertrophy. Such abnormalities not only increase vulnerability to upper airwayobstruction during sleep or anaesthesia, but also make intubation difficult. Whileproblems with airway maintenance may be obviated during anaesthesia by the use ofaids such as the laryngeal mask airway (LMA( dagger )), identification of risk andcaution are keys to management, and the airway should be secured before anaesthesiawhere doubt exists. If tracheal intubation is needed, spontaneous breathing untilintubation is an important principle. Every anaesthetist should have in mind a plan forfailed intubation or, worse, failed ventilation.

Publication Types: Review Review, Tutorial

J Arthroplasty. 2002 Aug;17(5):635-42.Sleep apnea syndrome in patients undergoing total joint arthroplasty.Parikh SN, Stuchin SA, Maca C, Fallar E, Steiger D.Departments of Orthopedics, NYU-Hospital for Joint Diseases, New York, NewYork 10003, USA.

Sleep apnea syndrome (SAS) is a condition of repeated episodes of apnea and hypopneaduring sleep. It can cause life-threatening morbidities, including cardiac arrhythmia andischemia, hypertension, and respiratory arrest, and even death. In a retrospective studyat our institution of patients who underwent hip or knee total joint arthroplasty (TJA)with a diagnosis of SAS, we hypothesized that avoiding factors that exacerbate SAS inthe perioperative period would minimize adverse outcomes. There were 19 patients witha preoperative diagnosis of moderate or severe SAS; 15 patients received continuouspositive airway pressure or bilevel positive airway pressure noninvasive ventilation, 1patient experienced respiratory arrest secondary to intraoperative propafol, and 2patients developed postoperative respiratory depression. Avoidance of opioids andsedative drugs, awareness of the possibility of acute airway obstruction, and close

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monitoring during and after surgery are vital in patients with SAS. Copyright 2002,Elsevier Science (USA). All rights reserved.

Publication Types: Case Reports

J Clin Anesth. 1995 Aug;7(5):417-21.Anesthetic management of a patient with obstructive sleep apnea syndromeand difficult airway access.Biro P, Kaplan V, Bloch KE.Department of Anesthesiology, University Hospital Zurich, Switzerland.

Patients with the obstructive sleep apnea syndrome (OSAS) are predisposed torespiratory complications under the influence of sedative and anesthetic drugs becauseof these drugs' alternation of respiratory control with a tendency for upper airwaycollapse. Additional difficulties for airway management during anesthesia may arise iffixed anatomic obstacles block the upper airway. We present a case of a patient withOSAS scheduled for general anesthesia for nasal polypectomy and correction of adeviated septum. Preoperative evaluation revealed several factors known to beassociated with difficult intubation and ventilation: nasal obstruction, maxillofacialmalformation (micrognathia), reduced temporomandibular joint mobility, and obesity.An individualized strategy of airway management based on published standards wasdeveloped and successfully applied. It involved fiberoptic guided intubation through alaryngeal mask airway. This case illustrates the management of patients with OSAS andadditional conditions that reduce upper airway patency.


Rev Esp Anestesiol Reanim. 1997 Dec;44(10):396-407.[Sleep apnea syndromes in adults and its anesthesiologic repercussions][Article in Spanish]Vazquez-Gutierrez T, Sanchez-Valderrabanos J, Caba-Barrientos F.Servicio de Anestesiologia, Hospital Universitario de Valme, Sevilla.

Adult sleep apnea syndrome is a common condition characterized by repeated apneicevents during sleep, producing hypoxia, a potentially neurovegetative response and lossof normal sleep structure. Important pathophysiological repercussions can ensue. Adultswith sleep apnea syndrome have particular upper airway sensitivity to sedatives, musclerelaxants, anesthetic agents and narcotic analgesics, potentially compromising theanesthetic management of such patients, among whom serious respiratory complicationshave been reported. This review describes current data for prevalence, etiopathogenesis,pathophysiological consequences, and the diagnosis and treatment of various forms ofthe syndrome. Also described is the approach to anesthetic care before, during and aftersurgery related to the specific condition or not.

Publication Types: Review

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Review, Tutorial

Masui. 1996 Apr;45(4):458-63.[Perioperative managements of a mentally retarded child with obstructivesleep apnea syndrome for adeno-tonsillectomy][Article in Japanese]Oohata H, Takada M, Ishizawa Y, Akamatsu S, Shimonaka H, Dohi S.Department of Anesthesiology and Critical Care Medicine, Gifu UniversitySchool of Medicine, Japan.

We describe a mentally retarded child with obstructive sleep apnea syndrome (OSAS) inwhom it was difficult to maintain upper airway in the perioperative period. The childunderwent awake intubation, because the preanesthetic evaluation of the airway with adirect fiberoptic visualization revealed a very narrow airway. Also we considered that ifwe used an anesthetic agent, a perioperative airway management would be verytroublesome. Postoperatively we continuously monitored for apnea and arrhythmias.When the child was sleeping, we found frequently that her thoratic movements weregetting weak and percutaneous oxygen saturation went down to about 70 percent.

The preoperative direct fiberoptic visualization of the upper airway is effective for theevaluation of the degree of airway obstruction in this child. We also recommend thecontinuous intensive postoperative monitorings including pulse oximetry, ECG, andapnea monitor which are very important to avoid life-threatening complications such asupper airway obstruction and serious arrhythmias in patients with obstructive sleepapnea syndrome.


Br J Anaesth. 2001 Feb;86(2):254-66.Loadsman JA, Hillman DR.Department of Anaesthetics, Royal Prince Alfred Hospital, Camperdown NSW,Australia.

Sleep disordered breathing is a common problem affecting all age groups, particularly inassociation with certain other medical conditions and syndromes. The pathologicalconsequences of the disorder may be severe, with significant implications for theperioperative management of sufferers. Research into the effects of surgery andanaesthesia on sleep is very much in its infancy. Understanding of the implications ofsleep disturbance and sleep disordered breathing for perioperative morbidity andmortality is limited. While several observations have led to considerable speculation inthe literature, evidence of a causal relationship is still largely lacking.

Anaesthetists are ideally placed to screen large numbers of people for sleep disorderedbreathing, a source of considerable community morbidity. Recognizing the symptoms,signs and associations of the condition during the preoperative visit is important inplanning management, as is recognition of the likelihood of OSA in patients who present

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difficulty with tracheal intubation or airway maintenance. Particular care is required inthe perioperative management of patients with diagnosed or suspected sleep apnoea.


Laryngoscope. 1989 Nov;99(11):1125-9.Perioperative complications and risk factors in the surgical treatment ofobstructive sleep apnea syndrome.Esclamado RM, Glenn MG, McCulloch TM, Cummings CW.Department of Otolaryngology--Head and Neck Surgery, University ofWashington, Seattle.

A retrospective review of 135 patients surgically treated for obstructive sleep apneasyndrome (OSAS) from 1982 to 1987 was performed to identify perioperativecomplications and potential risk factors.

The incidence of complications was 13% (18/135). Airway problems comprised 77%(14/18) of these complications, resulting in one death. There were three postoperativehemorrhages and one postoperative arrhythmia. Comparison of the complication groupversus the noncomplication group showed a statistically significant difference in theminimum oxygen saturation (66% vs. 79%) and apnea index (75 vs. 57) on the pre-operative sleep study and in the amount of narcotic administered intraoperatively.

Patients with intubation complications tended to be heavier, whereas patients withextubation complications received significantly more narcotic analgesia intraoperatively.Risk for a perioperative complication was not related to age, type of obstructivesymptoms, medical problems, or concurrent septoplasty/tonsillectomy. A protocol forperioperative airway management is presented.

Chest. 1995 Feb;107(2):367-74.Nasal continuous positive airway pressure in the perioperative management ofpatients with obstructive sleep apnea submitted to surgery.Rennotte MT, Baele P, Aubert G, Rodenstein DO.Department of Anesthesiology, Cliniques Universitaires Saint-Luc, UniversiteCatholique de Louvain, Brussels, Belgium.

Anesthetic, sedative, and analgesic drugs have been shown in animals and humans toselectively impair upper airway muscle activity. In patients with an already compromisedupper airway, these drugs may further jeopardize upper airway patency, especiallyduring sleep. Thus, patients with obstructive sleep apnea syndrome (OSAS) are at highrisk for surgery because of the use of the aforementioned drugs in the perioperativeperiod. It has been recommended that such drugs should be avoided or used withextreme caution in patients with OSAS submitted to surgery.

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We report herein on 16 adult patients with documented OSAS undergoing various typesof surgical procedures, including coronary artery bypass surgery. Anesthesia was carriedon with the usual type of drugs for each type of surgery. Postoperative opioid analgesiaand sedation were not restricted. The first patient, whose OSAS was diagnosed but nottreated, died after various complications, including a respiratory arrest in the ward. Thesecond patient experienced serious postoperative complications until a treatment forOSAS with nasal continuous positive airway pressure (N-CPAP) was instituted, andthereafter he made an uneventful recovery. The 14 following patients were started on N-CPAP before surgery, were put on N-CPAP as soon as extubated, on a near-continuousbasis, for 24 to 48 h and thereafter for all sleep periods. None of them had majorcomplications. The intensive care unit and hospital stays were the normal ones for eachtype of surgery in our institution.

CONCLUSION: We conclude that N-CPAP started before surgery and resumedimmediately after extubation allowed us to safely manage a variety of surgicalprocedures in patients with OSAS, and to freely use sedative, analgesic, and anestheticdrugs without major complications.Every effort should be made to identify patients with OSAS and institute N-CPAP therapybefore surgery.


Anesth Analg. 2003 May;96(5):1328-35, table of contents.The diagnosis of obstructive sleep apnea as a risk factor for unanticipatedadmissions in outpatient surgery.Sabers C, Plevak DJ, Schroeder DR, Warner DO.Anesthesia Clinical Research Unit, Department of Anesthesiology, Mayo Clinic,Rochester, Minnesota, USA.

The goal of this study was to determine whether the preoperative diagnosis ofobstructive sleep apnea (OSA) is an independent risk factor for perioperativecomplications in patients undergoing nonotorhinolaryngologic outpatient surgicalprocedures.

We used existing databases to identify 234 patients with polysomnography-confirmedOSA who had outpatient surgical procedures in the years 1997 through 2000. Controlpatients were matched for type of anesthesia, age, sex, body mass index, surgicalprocedure, and surgical date. Their perioperative medical records were reviewed. Therewas no significant difference in the intraoperative management of OSA and controlpatients, except that the laryngeal mask airway was less likely to be used in OSApatients. There was no significant difference in the rate of unplanned hospital admissions(23.9% versus 18.8%; odds ratio, 1.4; 95% confidence interval, 0.8-2.5) or otheradverse events (2.1% versus 1.3%; odds ratio, 1.7; 95% confidence interval, 0.4-7.0)between OSA and non-OSA patients.

Further, when admission did occur, it was generally unrelated to cardiac or respiratoryevents. In this retrospective analysis, the preoperative diagnosis of OSA was not a risk

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factor for either unanticipated hospital admission or for other adverse events amongpatients undergoing outpatient surgical procedures in a tertiary referral center.

IMPLICATIONS: In patients scheduled for outpatient surgery in a large academicpractice, the diagnosis of obstructive sleep apnea confirmed by polysomnography wasnot an independent risk factor for unanticipated hospital admission or for other adverseperioperative events.

Articles Children & Sleep Apnea

Anaesthesia. 1998 Jun;53(6):571-9.Obstructive sleep apnoea syndrome in children.Warwick JP, Mason DG.Nuffield Department of Anaesthetics, John Radcliffe Hospital, Oxford, UK.

Obstructive sleep apnoea syndrome in children is a complex disorder characterised byrepeated nocturnal episodes of increased upper airway resistive load. It is mostcommonly associated with adenotonsillar hypertrophy and more children are nowpresenting for adenotonsillectomy. These children may pose different anaestheticproblems to those having surgery for recurrent infection alone and anaesthetic morbidityand mortality has been reported. In addition, due to the varied symptomatology of thecondition, children with unrecognised obstructive sleep apnoea syndrome may presentfor incidental surgery. This is of importance as patients with undiagnosed obstructivesleep apnoea syndrome may experience additional peri-operative morbidity whenundergoing incidental surgery. This article aims to review the aetiology,pathophysiology, clinical presentation and anaesthetic management of children withobstructive sleep apnoea syndrome.

Publication Types: Review Review, Academic

Articles Oral Appliances & Sleep Apnea

Sleep. 1995 Jul;18(6):501-10.Oral appliances for the treatment of snoring and obstructive sleep apnea: areview.Schmidt-Nowara W, Lowe A, Wiegand L, Cartwright R, Perez-Guerra F, Menn S.Department of Medicine, University of New Mexico, Albuquerque 87131, USA.

This paper, which has been reviewed and approved by the Board of Directors of theAmerican Sleep Disorders Association, provides the background for the Standards ofPractice Committee's parameters for the practice of sleep medicine in North America.The 21 publications selected for this review describe 320 patients treated with oralappliances for snoring and obstructive sleep apnea. The appliances modify the upperairway by changing the posture of the mandible and tongue. Despite considerablevariation in the design of these appliances, the clinical effects are remarkably consistent.Snoring is improved and often eliminated in almost all patients who use oral appliances.

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Obstructive sleep apnea improves in the majority of patients; the mean apnea-hypopneaindex (AHI) in this group of patients was reduced from 47 to 19. Approximately half oftreated patients achieved an AHI of < 10; however, as many as 40% of those treatedwere left with significantly elevated AHIs. Improvement in sleep quality and sleepinessreflects the effect on breathing. Limited follow-up data indicate that oral discomfort is acommon but tolerable side effect, that dental and mandibular complications appear to beuncommon and that long-term compliance varies from 50% to 100% of patients.Comparison of the risk and benefit of oral appliance therapy with the other availabletreatments suggests that oral appliances present a useful alternative to continuouspositive airway pressure (CPAP), especially for patients with simple snoring and patientswith obstructive sleep apnea who cannot tolerate CPAP therapy.


Thorax. 1998 Aug;53 Suppl 2:S58-64.Oral appliances for the management of snoring and obstructive sleep apnoea.Bennett LS, Davies RJ, Stradling JR.Oxford Sleep Unit, Churchill Hospital, Osler Chest Unit, UK.

BACKGROUND: Although oral appliances are effective in some patients with obstructivesleep apnoea (OSA), they are not universally effective. A novel anterior mandibularpositioner (AMP) has been developed with an adjustable hinge that allows progressiveadvancement of the mandible. The objective of this prospective crossover study was tocompare efficacy, side effects, patient compliance, and preference between AMP andnasal continuous positive airway pressure (nCPAP) in patients with symptomatic mild tomoderate OSA.

METHODS: Twenty four patients of mean (SD) age 44.0 (10.6) years were recruited witha mean (SD) body mass index of 32.0 (8.2) kg/m2, Epworth sleepiness score 10.7(3.4), and apnoea/hypopnoea index 26.8 (11.9)/hour. There was a two week wash-inand a two week wash-out period and two treatment periods (AMP and nCPAP) each offour months. Efficacy, side effects, compliance, and preference were evaluated by aquestionnaire and home sleep monitoring.

RESULTS: One patient dropped out early in the study and three refused to cross over sotreatment results are presented on the remaining 20 patients. The apnoea/hypopnoeaindex (AHI) was lower with nasal CPAP 4.2 (2.2)/hour than with the AMP 13.6(14.5)/hour (p < 0.01). Eleven of the 20 patients (55%) who used the AMP weretreatment successes (reduction of AHI to < 10/hour and relief of symptoms), one (5%)was a compliance failure (unable or unwilling to use the treatment), and eight (40%)were treatment failures (failure to reduce AHI to < 10/hour and/or failure to relievesymptoms). Fourteen of the 20 patients (70%) who used nCPAP were treatmentsuccesses, six (30%) were compliance failures, and there were no treatment failures.There was greater patient satisfaction with the AMP (p < 0.01) than with nCPAP but nodifference in reported side effects or compliance.

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CONCLUSIONS: AMP is an effective treatment in some patients with mild to moderateOSA and is associated with greater patient satisfaction than nCPAP.


Thorax. 1997 Apr;52(4):362-8.A short-term controlled trial of an adjustable oral appliance for the treatmentof mild to moderate obstructive sleep apnoea.Ferguson KA, Ono T, Lowe AA, al-Majed S, Love LL, Fleetham JA.Division of Respiratory Medicine, University of British Columbia, Vancouver,Canada.

BACKGROUND: Although oral appliances are effective in some patients with obstructivesleep apnoea (OSA), they are not universally effective. A novel anterior mandibularpositioner (AMP) has been developed with an adjustable hinge that allows progressiveadvancement of the mandible. The objective of this prospective crossover study was tocompare efficacy, side effects, patient compliance, and preference between AMP andnasal continuous positive airway pressure (nCPAP) in patients with symptomatic mild tomoderate OSA.

METHODS: Twenty four patients of mean (SD) age 44.0 (10.6) years were recruited witha mean (SD) body mass index of 32.0 (8.2) kg/m2, Epworth sleepiness score 10.7(3.4), and apnoea/hypopnoea index 26.8 (11.9)/hour. There was a two week wash-inand a two week wash-out period and two treatment periods (AMP and nCPAP) each offour months. Efficacy, side effects, compliance, and preference were evaluated by aquestionnaire and home sleep monitoring.

RESULTS: One patient dropped out early in the study and three refused to cross over sotreatment results are presented on the remaining 20 patients. The apnoea/hypopnoeaindex (AHI) was lower with nasal CPAP 4.2 (2.2)/hour than with the AMP 13.6(14.5)/hour (p < 0.01). Eleven of the 20 patients (55%) who used the AMP weretreatment successes (reduction of AHI to < 10/hour and relief of symptoms), one (5%)was a compliance failure (unable or unwilling to use the treatment), and eight (40%)were treatment failures (failure to reduce AHI to < 10/hour and/or failure to relievesymptoms). Fourteen of the 20 patients (70%) who used nCPAP were treatmentsuccesses, six (30%) were compliance failures, and there were no treatment failures.There was greater patient satisfaction with the AMP (p < 0.01) than with nCPAP but nodifference in reported side effects or compliance.

CONCLUSIONS: AMP is an effective treatment in some patients with mild to moderateOSA and is associated with greater patient satisfaction than nCPAP.

Publication Types: Clinical Trial Controlled Clinical Trial

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Chest. 1996 May;109(5):1269-75.A randomized crossover study of an oral appliance vs nasal-continuous positiveairway pressure in the treatment of mild-moderate obstructive sleep apnea.Ferguson KA, Ono T, Lowe AA, Keenan SP, Fleetham JA.Department of Clinical Dental Sciences, University of British Columbia,Vancouver, BC, Canada.

STUDY OBJECTIVE: To compare efficacy, side effects, patient compliance, andpreference between oral appliance (OA) therapy and nasal-continuous positive airwaypressure (N-CPAP) therapy. DESIGN: Randomized, prospective, crossover study.

SETTING: University hospital and tertiary sleep referral center.

PATIENTS: Twenty-seven unselected patients with mild-moderate obstructive sleepapnea (OSA).

INTERVENTIONS: There was a 2-week wash-in and a 2-week wash-out period, and 2 x4-month treatment periods (OA and N-CPAP). Efficacy, side effects, compliance, andpreference were evaluated by a questionnaire and home sleep monitoring.

MEASUREMENTS AND RESULTS: Two patients dropped out early in the study andtreatment results are presented on the remaining 25 patients. The apnea/hypopneaindex was lower with N-CPAP (3.5 +/- 1.6) (mean +/- SD) than with the OA (9.7 +/-7.3) (p < 0.05). Twelve of the 25 patients who used the OA (48%) were treatmentsuccesses (reduction of apnea/hypopnea to <10/h and relief of symptoms), 6 (24%)were compliance failures (unable or unwilling to use the treatment), and 7 (28%) weretreatment failures (failure to reduce apnea/hypopnea index to <10/h and/or failure torelieve symptoms). Four people refused to use N-CPAP after using the OA. Thirteen ofthe 21 patients who used N-CPAP were overall treatment successes (62%), 8 werecompliance failures (38%), and there were no treatment failures. Side effects were morecommon and the patients were less satisfied with N-CPAP (p < 0.005). Seven patientswere treatment successes with both treatments, six of these patients preferred OA, andone preferred N-CPAP as a long-term treatment.

CONCLUSIONS: We conclude that OA is an effective treatment in some patients withmild-moderate OSA and is associated with fewer side effects and greater patientsatisfaction than N-CPAP.

FAQ’s

What Causes Sleep Apnea?Mechanical and structural problems in the airway cause the interruptions in breathingduring sleep.

Apnea occurs when the throat muscles and tongue relax during sleep andpartially block the opening of the airway. When the muscles of the soft palate

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at the base of the tongue and the uvula (the small fleshy tissue hanging fromthe center of the back of the throat) relax and sag, the airway becomesblocked, making breathing labored and noisy and even stopping it altogether.

Apnea also occurs when there is an excess amount of tissue in the airwaycausing it to be narrowed. With a narrowed airway, the person continues hisor her efforts to breathe, but air cannot easily flow into or out of the nose ormouth.

Ingestion of alcohol and sleeping pills increases the frequency andduration of breathing pauses in people with sleep apnea

Who Gets Sleep Apnea?Sleep apnea occurs in all age groups and both sexes but is more common in men (it maybe under diagnosed in women). It has been estimated that as many as 20 millionAmericans have sleep apnea.

Research estimates that 4% of middle-aged men and 2% of middle-aged women havesleep apnea along with excessive daytime sleepiness. People most likely to have ordevelop sleep apnea include:

Those who snore loudly or gasp during the night. Those who are overweight. Those who have high blood pressure. Those who have some physical abnormality in the nose, throat, or other

parts of the upper airway. Sleep apnea seems to run in some families, suggesting a possible genetic basis.

How is Normal Breathing Restored During Sleep?

During an apneic event, you are unable to breathe in oxygen and to exhale carbondioxide, resulting in low levels of oxygen and increased levels of carbon dioxide in theblood. The reduction in oxygen and increase in carbon dioxide alert the brain toresume breathing and cause an arousal.

With each arousal, a signal is sent from the brain to the upper airway muscles to openthe airway; breathing is resumed, often with a loud snort or gasp. Frequent arousals,although necessary for breathing to restart, prevent the patient from getting enoughrestorative, deep sleep.

When Should Sleep Apnea be Suspected? Heavy snoring A struggle to breath during sleep Overweight Waking up tired or unrested Falling asleep during the day (while driving, working, talking, watching TV, etc…)

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