niv (non invasive mechanical ventilation)
TRANSCRIPT
NON INVASIVE VENTILATION ( NIV
)Mohammad Rezaei, MDPediatric Pulmonologist
DEFINITIONVENTILATORY SUPPORT
InvasiveNon Invasive
Noninvasive ventilation (NIV):refers to the administration of ventilatory support without using an invasive artificial airway (endotracheal tube or tracheostomy tube).
HISTORY OF MECHANICAL VENTILATION
HISTORY OF MECHANICAL VENTILATION An unknown philosopher stated “The
lungs are the center of the universe and the seat of the soul”.
The earliest reference for attempts to restore breathing was about 3150 BC when Egyptian physicians tried to save drowned victims by placing a reed in the throat and blowing into the lungs . The Chinese in 2000 BC described lien ch’i, as a transfer of inspired air into the “soul” (life): mouth positive pressure.
HISTORY OF MECHANICAL VENTILATION
Hippocrates (460−375 BC) wrote the first directions for intubation in “Treatise on Air” by placing a “cannula into the trachea along the jaw bone so that air can be drawn into the lungs.”
HISTORY OF MECHANICAL VENTILATIONFirst written idea of assisted ventilation by:
Claudius Galen, a physician, in 128 AD who followed on this by experimentation by breathing into a hollow reed placed in the throats of many different animals, and noted that their chests expanded.
HISTORY OF MECHANICAL VENTILATION The first recorded attempt of “mechanical”
ventilation was in 1550, attributed to Paracelsus, when he used a fire bellows as a device connected to a tube inserted in the patient’s mouth to blow air into the lungs to assist breathing, an “IPPB”.
HISTORY OF MECHANICAL VENTILATION
It was John Mayow, an English physician-scientist in 1673, who first conceived and built an external negative pressure ventilator, which consisted of a unit with a bellows and a bladder to pull and expel air, suggesting that this mimicked the action of the inspiratory muscles . While he was also the first to show the necessity of oxygen for life, preceding Priestley, he did not name it.
His work remained obscure until 1832.
HISTORY OF MECHANICAL VENTILATION
First modern negative pressure ventilator: John Dalziel (1832)
“tank respirator”: Patient sitting in an air tight box with head sticking out with manual bellows
Dr. Robert Lewins modified it. Alfred E. Jones from USA, following a similar
design, patented the first American tank respirator in 1864. He treated asthma and bronchitis with his device
HISTORY OFMECHANICALVENTILATION
first American
tank respirator
HISTORY OFMECHANICALVENTILATION
“Spirophore”
HISTORY OFMECHANICALVENTILATION
Alexander Graham Bell, the inventor of the telephone, and not a physician, after the death of his 1-day-old son in 1881 designed a metal vacuum jacket in 1882, which developed negative pressures with a separate hand pump to artificially “expand’ the lungs to save lives. It was a unit made of two rigid halves with soft linings held to the chest by a strap, with negative pressure provided by large bellows. He successfully experimented with healthy volunteers.
HISTORY OFMECHANICALVENTILATION
The first widely used negative pressure ventilator: The Drinker Respirator (aka Emerson
Iron Lung)
Designed by Philip Drinker and Louis Agassiz Shaw Jr. (1928), Powered by an electric motor and 2 air pumps from a vacuum cleaner.
The first clinical use of the Drinker respirator on a human was on October 12, 1928, at the Boston Children's Hospital. The subject was an eight-year-old girl who was nearly dead as a result of respiratory failure due to polio. Her dramatic recovery, within less than a minute of being placed in the chamber, helped popularize the new device.
An example of the Drinker and Shaw negative-pressure ventilator (IRON LUNG).
HISTORY OFMECHANICALVENTILATION
Boston Children’s Hospital 4 patient chamber ventilator
A Both cabinet respirator being used to treat a patient at the 110th Australian Military Hospital in 1943
EMERSON IRON LUNGIn 1931, John Haven Emerson (February 5, 1906 – February 4, 1997) introduced and improved upon a less expensive iron lung. The Emerson iron lung had a bed that could slide in and out of the cylinder as needed, and the tank had portal windows which allowed attendants to reach in and adjust limbs, sheets, or hot packs
Rancho Los Amigos Hospital, California (1953) Iron lung from the 1950s in the Gütersloh Town Museum
This iron lung was donated to the CDC’s Global Health Odyssey by the family of polio patient Mr. Barton Hebert of Covington, Louisiana, who’d used the device from the late 1950s until his death in 2003.
HISTORY OFMECHANICALVENTILATION In 1959, there were 1,200 people using tank
respirators in the United States, but by 2004 there were only 39. By 2014, there were only 10 people left with an iron lung
HISTORY OFMECHANICALVENTILATIONMovement away from negative pressure devices
(1960s) Large, taking up much space, difficult to access
patient No PEEP Significant leakage leading to patient cooling “Tank shock” – blood pooling in abdomen and lower
extremities
HISTORY OFMECHANICALVENTILATION
they were used for the first time in Blegdams Hospital, Copenhagen, Denmark, during a polio outbreak in 1952.[It proved a success and soon superseded the iron lung throughout Europe.
are now more common than negative pressure systems.
Positive pressure
ventilation
HISTORY OFMECHANICALVENTILATION In 1980s it was recognized that delivery of
continuous positive airway pressure by close fitting nasal masks for treatment of obstructive sleep apnea could also be used to deliver an intermittent positive pressure NIPPV
NIV Decreased incidence of nosocomial infections Improves patient comfort Minimal sedation requirement Less painful Accelerates weaning decreased ICU length of stay, mortality Decreased costs
Potential Benefits
NIV Negative pressure (NNPV):
Positive pressure (NIPPV): TECHNIQUES OF
APPLICATION
NEGATIVE PRESSURE VENTILATION These devices create negative pressure around the chest wall and augment the tidal volume.
NON INVASIVE POSITIVE PRESSURE VENTILATION
During NIPPV, air enters the nose, mouth or both through the interface, which in turn is connected, to Positive Pressure Ventilator.
NIPPVInterface
s
NIPPVInterface (Nasal)
NIV
Nasal masks (general advantages) Best suited for more cooperative patients Better in patients with a lower severity of illness Not claustrophobic Allows speaking, drinking, coughing, and secretion
clearance Less aspiration risk with emesis Generally better tolerated Nasal masks (cautions, disadvantages) More leaks possible (eg, mouth-breathing or edentulous
patients) Effectiveness limited in patients with nasal deformities or
blocked nasal passages
Interfaces
NIPPVInterfaces(OroNasal)
NIV
Orofacial masks (general advantages) Best suited for less cooperative patients Better in patients with a higher severity of illness Better for patients with mouth-breathing or pursed-lips
breathing Better in edentulous patients Generally more effective ventilation Orofacial masks (cautions, disadvantages) Claustrophobic Hinder speaking and coughing Risk of aspiration with emesis
Interfaces
NIPPVInterfaces (Helmet)
NIPPVInterface
s
Variables Nasal OroNasalComfort +++ ++Claustrophobia + ++Rebreathing + ++Permits expectoration ++ +Permits speech ++ +Permits eating + -Function if nose obstructed - +
INTERFACES
Clinical trials have not demonstrated the superiority of any interface
Although:• the nasal mask may be more effective in patients
with a lower severity of illness.
• In patients with a higher severity of illness the orofacial mask and total face mask appear to result in comparable outcomes.
NIV
Coma Cardiac arrest Respiratory arrest Any condition requiring immediate intubation Cardiac instability
Shock and need for pressor support Ventricular dysrhythmias Complicated acute myocardial infarction
GI bleeding - Intractable emesis and/or uncontrollable bleeding Inability to protect airway
Impaired cough or swallowing Poor clearance of secretions Depressed sensorium and lethargy
Status epilepticus Inability to fix the interface
facial -abnormalities, burns, trauma, anomalies Potential for upper airway obstruction
Extensive head and neck tumors Any other tumor with extrinsic airway compression Angioedema or anaphylaxis causing airway compromise
Non availability of trained medical personnel
CONTRAINDICATIONS
NIV
Patient cooperation (an essential component that excludes agitated, belligerent, or comatose patients)
Dyspnea (moderate to severe, but short of respiratory failure)
Tachypnea Increased work of breathing (accessory muscle use,
pursed-lips breathing) Hypercapnic respiratory acidosis (pH range 7.10-7.35) Hypoxemia (PaO 2/FIO 2 < 200 mm Hg, best in rapidly
reversible causes of hypoxemia)
Patient inclusion criteria
NIV1. A co-operative patient who can control their airway and secretions with an adequate cough reflex. The patient should be able to co-ordinate breathing with the ventilator and breathe unaided for several minutes.
2. Hemodynamically stable
Requirements for
SuccessfulNIV support
NIV
Chronic obstructive pulmonary disease Cardiogenic pulmonary edema After discontinuation of mechanical ventilation (COPD) Community-acquired pneumonia (and COPD) Asthma Immunocompromised state Postoperative respiratory distress and respiratory failure Do-not-intubate status Neuromuscular respiratory failure Decompensated obstructive sleep apnea/cor pulmonale Cystic fibrosis Mild Pneumocystic carinii pneumonia
Suitable Clinical
Conditions for NIV
NIPPVVolume ventilatorPressure-controlled
Choosing the initial mode of ventilation is based on:past experiencecapability of ventilators availablecondition being treated
Modes of ventilation
NIPPV Controlled mechanical ventilation:
No patient effort Referred as Timed (T) mode Similar to PCV
Assist mode: Ventilatory support to patients effort. No backup Referred to spont. (S) mode Similar to PSV
Assist control ventilation: Ventilatory support in response to pt. effort and backup safety
rate if pt. does not trigger Referred as spontaneous/timed (S/T) mode Similar to PS with apnea backup with PC breaths
Modes of ventilation
NIPPV CPAP:
A constant pressure is applied to airway throughout the cycle
Used primarily to correct hypoxemia Not a ventilatory mode Main indication- cardiogenic pulmonary edema, OSA, …
Modes of ventilation
NIPPV Proportional Assist Ventilation (PAV)
By instantaneously tracking patient inspiratory flow and its integral (volume) using an in-line pneumotochograph, this mode has the capability of responding rapidly to the patient’s ventilatory effort.
By adjusting the gain on the flow and volume signals, one can select the proportion of breathing work that is to be assisted.
Modes of ventilation
NIPPVOther Modes of Noninvasive Ventilatory Assistance Modes of
ventilation
NIPPVMost patients who are provided noninvasive
ventilation are provided support with pressure ventilation, with continuous positive airway pressure (CPAP), which is the most basic level of support.
CPAP may be especially useful in patients with congestive heart failure or obstructive sleep apnea
Modes of ventilation
NIVPressure
Waveform CPAP
0
PRESSURE
NIPPVBilevel positive airway pressure (BiPAP) is
probably the most common mode noninvasive positive pressure ventilation and requires provisions for inspiratory positive airway pressure (IPAP) and expiratory positive airway pressure (EPAP).
The difference between IPAP and EPAP is a reflection of the amount of pressure support ventilation provided to the patient, and EPAP is synonymous with positive end-expiratory pressure (PEEP).
Modes of ventilation
NIVBi-PAP and Changes in
EPAP Pressure5 cm
Delta P 10 cm
10 cm
15 cm
Delta pressure 5 cm
EPAP increased to 10 cm
IPAP increased to 20 cm
Delta P returned to 10 cm
PRESSURE
Decreasing delta pressure will usually result in lower Vt
NIV
recognize that certain parameters may predict successful noninvasive ventilation or failure of noninvasive ventilation. reflection of the patient's ability to cooperate with noninvasive
ventilation, patient-ventilatory synchrony, noninvasive ventilation effectiveness
Trials of noninvasive ventilation are usually 1-2 hours in length and are useful to determine if a patient can be treated with noninvasive ventilation. Extended trials without significant improvement are not recommended because this
only delays intubation and mechanical ventilation
Predictors of successful
noninvasive ventilation
NIVPredictors of success - Response to trial of NIV (1-2 h)
Decrease in PaCO2 greater than 8 mm Hg Improvement in pH greater than 0.06 Correction of respiratory acidosis
Predictors of successful
noninvasive ventilation
NIVfailure to NIV
No improvement in gas exchange or dyspnea progressively increases
Deterioration or no change in the mental condition of the hypercapnic patients
Need for airway protection Hemodynamic instability Fresh MI or arrhythmias Patient unable to tolerate the mask
When to intubate during NIV???
NIV
Facial and nasal pressure injury and sores Result of tight mask seals used to attain adequate inspiratory volumes Minimize pressure by intermittent application of noninvasive ventilation Schedule breaks (30-90 min) to minimize effects of mask pressure Balance strap tension to minimize mask leaks without excessive mask pressures Cover vulnerable areas (erythematous points of contact) with protective dressings
Gastric distension Rarely a problem Avoid by limiting peak inspiratory pressures to less than 25 cm water Nasogastric tubes can be placed but can worsen leaks from the mask Nasogastric tube also bypasses the lower esophageal sphincter and permits reflux
Dry mucous membranes and thick secretions Seen in patients with extended use of noninvasive ventilation Provide humidification for noninvasive ventilation devices Provide daily oral care
Aspiration of gastric contents Especially if emesis during noninvasive ventilation Avoid noninvasive ventilation in patient with ongoing emesis or hematemesis
Complications of
Noninvasive Ventilation
NIVComplications of both noninvasive and invasive ventilation
Barotrauma (significantly less risk with noninvasive ventilation)
Hypotension related to positive intrathoracic pressure (support with fluids)
Complications of
Noninvasive Ventilation
NIVComplications Avoided by Noninvasive Ventilation
Ventilator-associated pneumonia Sinusitis Reduction in need for sedative agents - Sedatives used in
less than 15% of noninvasive ventilation patients in one survey
Complications Avoided
by Noninvasive Ventilation
BIPHASIC CUIRASS VENTILATION (BCV)
BCV is a modern development of the iron lung, consisting of a wearable rigid upper-body shell (a cuirass) which functions as a negative pressure ventilator. The ventilation is biphasic because the cuirass is attached to a pump which actively controls both the inspiratory and expiratory phases of the respiratory cycle. This method is a modern improvement of 'negative pressure ventilation' (NPV), which could only control inspiratory breathing, relying on passive recoil for exhalation. BCV was developed by Dr Zamir Hayek, a pioneer in the field of assisted ventilation.
* Patient selection is crucial
1. Appropriately monitored location, oximetry, respiratory impedance, vital signs as clinically indicated
2. Patient in bed or chair at >30 angle
3. Select and fit interface
4. Select ventilator
5. Apply headgear; avoid excessive strap tension (one or two fingers under strap)
6. Connect interface to ventilator tubing and turn on ventilator
7. Start with low pressure in spontaneously triggered mode with backup rate; (pressure limited: 8 to 12 cm H2O inspiratory pressure; 3 to 5 cm H2O expiratory pressure)
8. Gradually increase inspiratory pressure (10 to 20 cm H2O) as tolerated to achieve alleviation of dyspnea, decreased respiratory rate, increased tidal volume (if being monitored), and good patient-ventilator synchrony
9. Provide O2 supplementation as need to keep O2 sat >90 percent
10. Check for air leaks, readjust straps as needed
11. Add humidifier as indicated
12. Consider mild sedation (eg, intravenously administered lorazepam 0.5 mg) in agitated patients
13. Encouragement, reassurance, and frequent checks and adjustments as needed
14. Monitor occasional blood gases (within 1 to 2 hours) and then as needed
Protocol for initiation of noninvasive positive pressure ventilation
THANK YOU FOR YOUR ATTENTION