airway management part 1

Airway ManagementPart 1

EMS Professions

Temple College

Topics for Discussion

Airway Maintenance Objectives Airway Anatomy & Physiology Review Causes of Respiratory Difficulty & Distress Assessing Respiratory Function Methods of Airway Management Methods of Ventilatory Management Common Out-of-Hospital Equipment Utilized Advanced Methods of Airway Management and

Ventilation Risks to the Paramedic

Objectives of Airway Management & Ventilation

Primary Objective: Ensure optimal ventilation

Deliver oxygen to bloodEliminate carbon dioxide (C02) from body

Definitions What is airway management? How does it differ from spontaneous,

manual or assisted ventilations?

Objectives of Airway Management & Ventilation

Why is this so important? Brain death occurs rapidly; other tissue

follows EMS providers can reduce additional

injury/disease by good airway, ventilation techniques

EMS providers often neglect BLS airway, ventilation skills

Airway Anatomy Review

Upper Airway AnatomyLower Airway AnatomyLung Capacities/VolumesPediatric Airway Differences

Anatomy of the Upper Airway

Upper Airway Anatomy

Functions: warm, filter, humidify airNasal cavity and nasopharynx

Formed by union of facial bones Nasal floor towards ear not eye Lined with mucous membranes, cilia Tissues are delicate, vascular Adenoids

Lymph tissue - filters bacteriaCommonly infected


Oral cavity and oropharynx Teeth Tongue

Attached at mandible, hyoid boneMost common airway obstruction cause

PalateRoof of mouthSeparates oropharynx and nasopharynxAnterior= hard palate; Posterior= soft palate


Oral cavity and oropharynx Tonsils

Lymph tissue - filters bacteriaCommonly infected

EpiglottisLeaf-like structureCloses during swallowingPrevents aspiration

Vallecula“Pocket” formed by base of tongue, epiglottis


Sinuses cavities formed by

cranial bones act as tributaries

for fluid to, from eustachian tubes, tear ducts

trap bacteria, commonly infected


Larynx Attached to hyoid bone

Horseshoe shaped boneSupports trachea

Thyroid cartilageLargest laryngeal cartilageShield-shapedCartilage anteriorly, smooth muscle posteriorly“Adam’s Apple”Glottic opening directly behind


Larynx Glottic opening

Adult airway’s narrowest pointDependent on muscle toneContains vocal bands

Arytenoid cartilagePosterior attachment of vocal bands


Larynx Cricoid ring

First tracheal ringCompletely cartilaginousCompression (Sellick maneuver) occludes

esophagus

Cricothyroid membraneMembrane between cricoid, thyroid cartilagesSite for surgical, needle airway placement


Larynx and Trachea Associated Structures

Thyroid gland• below cricoid cartilage• lies across trachea, up both sides

Carotid arteries• branch across, lie closely alongside trachea

Jugular veins• branch across and lie close to trachea


Pediatric vs Adult Upper Airway Larger tongue in comparison to size of

mouth Floppy epiglottis Delicate teeth, gums More superior larynx Funnel shaped larynx due to undeveloped

cricoid cartilage Narrowest point at cricoid ring before ~8

years old


From: CPEM, TRIPP, 1998

Glottic Opening

Lower Airway Anatomy

Function Exchange O2 , CO2 with blood

Location From glottic opening to alveolar-

capillary membrane


Trachea Bifurcates (divides) at carina Right, left mainstem bronchi Right mainstem bronchus shorter,

straighter Lined with mucous cells, beta-2

receptors


Bronchi Branch into secondary, tertiary bronchi

that branch into bronchiolesBronchioles

No cartilage in walls Small smooth muscle tubes Branch into alveolar ducts that end at

alveolar sacs


Alveoli “Balloon-like” clusters Site of gas exchange Lined with surfactant

Decreases surface tension eases expansion

surfactant atelectasis (focal collapse of alveoli0


Lungs Right lung = 3 lobes; Left lung = 2 lobes Parenchymal tissue Pleura

VisceralParietalPleural space


Occlusion of bronchioles Smooth muscle

contraction (bronchospasm

Mucus plugs Inflammatory

edema Foreign bodies

Lung Volumes/Capacities

Typical adult male total lung capacity = 6 liters

Tidal Volume (VT) Gas volume inhaled or exhaled during

single ventilatory cycle Usually 5-7 cc/kg (typically 500 cc)


Dead Space Air (VD) Air unavailable for gas exchange


Dead Space Air (VD) Anatomic dead space (~150cc)

TracheaBronchi

Physiologic dead spaceShunting

Pathological dead spaceFormed by factors like disease or obstructionExamples: COPD


Alveolar Air (alveolar volume) [VA] Air reaching alveoli for gas exchange Usually 350 cc


Minute Volume [Vmin](minute ventilation) Amount of gas moved in, out of respiratory

tract per minute Tidal volume X RR

Alveolar Minute Volume Amount of gas moved in, out of alveoli per

minute (tidal volume - dead space volume) X RR


Functional Reserve Capacity (FRC) After optimal inspiration, amount of air

that can be forced from lungs in single exhalation


Inspiratory Reserve Volume (IRV) Amount of gas that can be inspired in

addition to tidal volumeExpiratory Reserve Volume (ERV)

Amount of gas that can be expired after passive (relaxed) expiration

Ventilation

Movement of air in, out of lungsControl via:

Respiratory center in medulla Apneustic, pneumotaxic centers in pons

Ventilation Inspiration

Stimulus from respiratory center of brain (medulla) Transmitted via phrenic nerve to diaphragm, spinal

cord/intercostal nerves to intercostal muscles Diaphragm contracts, flattens Intercostal muscles contract; ribs move up and out Air spaces in lungs stretch, increase in size intrapulmonic pressure (pressure gradient) Air flows into airways, alveoli inflate until pressure

equalizes

Ventilation

Expiration Stretch receptors in lungs signal respiratory

center via vagus nerve to inhibit inspiration (Hering-Breuer reflex)

Natural elasticity of lungs pulls diaphragm, chest wall to resting position

Pulmonary air spaces decrease in size Intrapulmonary pressure rises Air flows out until pressure equalizes

Ventilation

Ventilation

Respiratory Drive Chemoreceptors in medulla Stimulated PaCO2 or pH

PaCO2 is normal neuroregulatory control of ventilations

Hypoxic Drive Chemoreceptors in aortic arch, carotid bodies Stimulated by PaO2

Back-up regulatory control

Ventilation

Other stimulants or depressants Body temp: fever; hypothermia Drugs/meds: increase or decrease Pain: increases, but occasionally

decreases Emotion: increases Acidosis: increases Sleep: decreases

Gas Measurements

Total Pressure Combined pressure of all atmospheric

gases 760 mm Hg (torr) at sea level

Partial Pressure Pressure exerted by each gas in a

mixture

Gas Measurements

Partial Pressures Atmospheric

Nitrogen 597.0 torr (78.62%); Oxygen 159.0 torr (20.84%); Carbon Dioxide 0.3 torr (0.04%); Water 3.7 torr (0.5%)

Alveolar Nitrogen 569.0 torr (74.9%); Oxygen 104.0

torr (13.7%); CO2 40.0 torr (5.2%); Water 47.0 torr (6.2%)

Respiration

Ventilation vs. RespirationExchange of gases between living

organism, environmentExternal Respiration

Exchange between lungs, blood cellsInternal Respiration

Exchange between blood cells, tissues

Respiration

How are O2, CO2 transported? Diffusion

Movement of gases along a concentration gradient

Gases dissolve in water, pass through alveolar membrane from areas of higher concentration to areas of lower concentration

FiO2

% oxygen in inspired air expressed as a decimal FiO2 of room air = 0.21

Respiration

Blood Oxygen Content dissolved O2 crosses capillary membrane,

binds to Hgb of RBC Transport = O2 bound to hemoglobin

(97%) or dissolved in plasma O2 Saturation

% of hemoglobin saturated with oxygen (usually carries >96% of total)

O2 content divided by O2 carrying capacity

Respiration

Oxygen saturation affected by: Low Hgb (anemia, hemorrhage) Inadequate oxygen availability at alveoli Poor diffusion across pulmonary membrane

(pneumonia, pulmonary edema, COPD) Ventilation/Perfusion (V/Q) mismatch

Blood moves past collapsed alveoli (shunting)Alveoli intact but blood flow impaired

Respiration

Blood Carbon Dioxide Content Byproduct of work (cellular respiration) Transported as bicarbonate (HCO3

- ion) 20-30% bound to hemoglobin Pressure gradient causes CO2 diffusion

into alveoli from blood Increased level = hypercarbia

Respiration

Alveoli PO2 100 & PCO2 40

PO2 40 & PCO2 46 - Pulmonary circulation - PO2 100 & PCO2 40

Heart

PO2 40 & PCO2 46 - Systemic circulation - PO2 100 & PCO2 40

Tissue cell PO2 <40 & PCO2 >46

Inspired Air: PO2 160 & PCO2 0.3

OxygenatedDeoxygenated

Diagnostic Testing

Pulse OximetryPeak Expiratory Flow TestingPulmonary Function TestingEnd-Tidal CO2 MonitoringLaboratory Testing of Blood

Arterial Venous

Causes of Hypoxemia

Lower partial pressure of atmospheric O2

Inadequate hemoglobin level in bloodHemoglobin bound by other gas (CO) pulmonary alveolar membrane distanceReduced surface area for gas exchangeDecreased mechanical effort

Causes of Airway/Ventilatory Compromise

Airway Obstruction Tongue Foreign body obstruction Anaphylaxis/angioedema Upper airway burn Maxillofacial/laryngeal/trachebronchial

trauma Epiglottitis Croup

Obstruction

Tongue Most common cause Snoring respirations Corrected by positioning

Foreign Body

Partial or FullSymptoms include

Choking Gagging Stridor Dyspnea Aphonia Dysphonia

Laryngeal Spasm

Spasmatic closure of vocal cordsFrequently caused by

Overly aggressive technique during intubation

Immediately upon extubation

Laryngeal Edema

Causes Angioedema Anaphylaxis Upper airway burns Epiglottitis Croup Trauma

Aspiration

Significantly increases mortality Obstructs Airway Destroys bronchial tissue Introduces pathogens Decreases ability to ventilate Frequently occult

Obstructive Airway Disease

Obstructive airway disease Asthma Emphysema Chronic Bronchitis

Gas Exchange Surface

Pulmonary edema Left-sided heart failure Toxic inhalation Near drowning

PneumoniaPulmonary embolism

Blood clots Amniotic fluid Fat embolism


Thoracic Bellows Chest trauma

Fib fracturesFlail chestPneumothoraxHemothoraxSucking chest woundDiaphragmatic hernia


Thoracic Bellows Pleural effusion Spinal cord trauma Morbid obesity (Pickwickian Syndrome) Neurological/neuromuscular disease

PoliomyelitisMyasthenia gravisMuscular dystrophyGullian-Barre syndrome


Control System Head trauma Cerebrovascular accident Depressant drug toxicity

NarcoticsSedative-HypnoticsEthanol

Assessment of Airway/Ventilatory Compromise

Respiratory Distress/Dyspnea = Possible Life Threat

Assess/Manage SimultaneouslyPriorities

Airway Breathing Circulation Disability


Airway Listen to patient talk/breathe Noisy breathing = Obstructed breathing But, all obstructed breathing is not noisy Adventitious sounds

Snoring = TongueStridor = “Tight” Upper Airway


Breathing Look

Symmetry of Chest ExpansionSigns of Increased EffortSkin Color

ListenMouth and NoseLung Fields

FeelMouth and NoseSymmetry of Expansion


Breathing Tachypnea Bradypnea Signs of distress

Nasal flaringTracheal tuggingRetractionsAccessory muscle useTripod positioning

Cyanosis


Circulation Don’t let respiratory failure distract

you!!! Tachycardia = Early hypoxia in adults Bradycardia = Early hypoxia in infants,

children; Late hypoxia in adults


Disability Restlessness, anxiety, combativeness =

hypoxia until proven otherwise Drowsiness, lethargy = hypercarbia

until proven otherwise When the fighting stops, a patient isn’t

always getting better


Focused Exam Respiratory Patterns

Cheyne-Stokes = diffuse cerebral cortex injury

Kussmaul = acidosisBiot’s (cluster) = increased ICP; pons, upper

medulla injuryCentral Neurogenic Hyperventilation =

increased ICP; mid-brain injuryAgonal = brain anoxia


Focused Exam Neck

Trachea mid-line?Jugular vein distension?Subcutaneous emphysema?Accessory muscle use?/hypertrophy?


Focused Exam Chest

Barrel chest?Deformity, discoloration, asymmetry?Flail segment, paradoxical movement?Adventitious breath sounds?Third heart sound?Subcutaneous emphysema?Fremitus?Dullness, hyperresonance to percussion?


Focused Exam Extremities

Edema?Nail bed color?Clubbing?


Mechanical Ventilation Increased resistance Changing compliance


Pulsus Paradoxus Systolic BP drops > 10 mm Hg

w/inspiration May detect change in pulse quality COPD, asthma, pericardial tamponade


History Onset gradual or sudden? What makes it worse, better? How long? Cough? Productive? Of what? Pain? What kind? Fever?


Past History Hypertension, AMI, diabetes Chronic cough, smoking, recurrent “colds” Allergies, acute/seasonal SOB Lower extremity trauma, recent surgery,

immobilization

Interventions Past admission? Ever admitted to ICU? Medications? Frequency of prn medication use? Ever intubated before?

BLS Airway/Ventilation Methods

Supplemental Oxygen Increased FiO2 increases available

oxygen Objective = Maximize hemoglobin

saturation

Oxygen Equipment

Oxygen source Compressed gas

Tank size• D 400L• E 660L• M 3450 L

Liquid oxygen

Oxygen Equipment

Regulators High Pressure

Cylinder to cylinder Low Pressure

Cylinder to patient

Humidifier

Delivery Devices

Nasal cannulaSimple face maskPartial rebreather maskNon-rebreather maskVenturi maskSmall volume nebulizer

Nasal Cannula

Optimal delivery 40% at 6 LPMIndication

Low FiO2

Long term therapyContraindications

Apnea Mouth breathing Need for High FiO2

Venturi Mask

Specific O2 Concentrations 24% 28% 35% 40%

Simple Face Mask

Range 40-60% at 10 LPMVolumes greater that 10 LPM does

not increase O2 deliveryIndications

Moderate FiO2

Contraindications Apnea Need for High FiO2

Non-Rebreather Mask

Range 80-95% at 15 LPMIndications

Delivery of high FiO2Contraindications

Apnea Poor respiratory effort

Partial Rebreather

Range 40 – 60%Indications

Moderate FiO2

Contraindications Apnea Need for High FiO2


Airway Maneuvers Head-tilt/Chin-lift Jaw thrust Sellick’s maneuver

Other Types Tracheostomy with tube Tracheostomy with stoma

Airway Devices Oropharyngeal airway Nasopharyngeal airway


Mouth-to-MouthMouth-to-NoseMouth-to-MaskOne-person BVMTwo-person BVMThree-person BVMFlow-restricted, gas powered ventilatorTransport ventilator


Mouth to MouthMouth to NoseMouth to Mask


One-Person BVM Difficult to master Mask seal often inadequate May result in inadequate tidal volume Gastric distention risk Ventilate only until see chest rise


Two-person BVM Most efficient method Useful in C-spine injury improved mask seal, tidal volume

Three-person BVM Less utilized Used when difficulty with mask seal Crowded


Flow-restricted, gas-powered ventilator Cardiac sphincter opens at 30 cm H2O High volume/high concentration Not recommended for children, poor

pulmonary compliance, or poor tidal volume

Oxygen delivered on inspiratory effort May cause barotrauma


Automatic transport ventilators Not like “real” ventilator Usually only controls volume, rate Useful during prolonged ventilation times Not useful in obstructed airway, increased

airway resistance Frees personnel Cannot respond to changes in airway

resistance, lung compliance


Pediatric considerations Mask seal force may obstruct airway Best if used with jaw thrust BVM sizes: neonate, infant=450 ml + Children > 8 y.o. require adult BVM Just enough volume to see chest rise Squeeze - Release - Release


Stoma patients Expose stoma Pocket mask BVM

Seal around stoma siteSeal mouth, nose if air leak is evident


Airway obstruction techniques Positioning Finger sweep with caution Suctioning Oral airway/nasal airway (tongue) Heimlich maneuver Chest thrusts Chest thrust/back blows for infants Direct laryngoscopy


Suctioning Manual or powered devices Suction catheters

RigidSoft


Gastric Distention Common when ventilating without

intubation Complications

Pressure on diaphragmResistance to BVM ventilationVomiting, aspiration

Increase BVM ventilation time

airway management part 1

Health & Medicine

bls airway ventilation methods

airway management

airway management

person bvm

respiratory center

o2 40

o2 100

mouth mouth