7.4 Non-Invasive Ventilation
Key Takeaways
Continuous positive airway pressure is one pressure for flash pulmonary edema; bilevel positive airway pressure adds inspiratory support for cooperative hypercapnic chronic obstructive pulmonary disease.
Non-invasive ventilation is contraindicated in vomiting, an unprotected airway, facial trauma, untreated pneumothorax, arrest, and altered mental status that will not tolerate a mask.
High-flow nasal cannula treats hypoxemia; it is not a carbon dioxide-clearance substitute for bilevel support.
Mask leak, battery, and oxygen consumption fail non-invasive therapy in flight even when the indication was right.
Non-invasive ventilation is a short reversible bridge; a tiring or vomiting patient should have been intubated on the ground.
Not every failing lung needs a tube before lift. Domain 2 of the August 2026 Board of Certification for Emergency Nursing (BCEN) Certified Flight Registered Nurse (CFRN) outline tests non-invasive ventilation (NIV) as an indication, a contraindication, and an oxygen-and-power problem. Continuous positive airway pressure (CPAP) and bilevel positive airway pressure (BiPAP) keep some patients off a laryngoscope. They also drown a vomiting patient and empty a medical aircraft's oxygen in twenty minutes if you do not do the math.
CPAP, BiPAP, and high-flow nasal cannula
What each device actually does
CPAP is one pressure all the time. It recruits flooded alveoli, raises functional residual capacity (FRC), and unloads the left ventricle by cutting preload and afterload. That is why it is first-line for flash pulmonary edema once nitroglycerin and blood pressure allow. It does not give a large inspiratory boost, so a tiring chronic obstructive pulmonary disease (COPD) patient may still fail.
BiPAP (the common transport NIV mode) sets an inspiratory positive airway pressure (IPAP) and an expiratory positive airway pressure (EPAP). The difference is pressure support. EPAP is the positive end-expiratory pressure (PEEP). BiPAP is the usual choice for COPD or asthma with hypercapnic respiratory failure who is still protecting the airway. Typical adult starting ranges many programs teach—clinical teaching, not BCEN numbers—are EPAP 5 cm H2O and IPAP 10–15 cm H2O, then titrate to work of breathing and exhaled carbon dioxide.
High-flow nasal cannula (HFNC) delivers heated, humidified oxygen at 30–60 L/min in adults, with a small amount of PEEP if the mouth stays closed. It is a hypoxemia tool. It is not a substitute for BiPAP when the problem is carbon dioxide clearance.
| Therapy | Best flight indication | Weakness |
|---|---|---|
| CPAP | Flash cardiogenic pulmonary edema, still awake | Little help for a tiring carbon dioxide retainer |
| BiPAP / NIV | COPD or asthma with hypercapnia, protecting the airway | Fails if the mask leaks or the patient vomits |
| HFNC | Isolated hypoxemia, bridge off a mask | Poor carbon dioxide clearance; eats oxygen at high flow |
On the ramp, wet lungs plus hypertension point toward edema and CPAP. A long smoker with a tight chest and a rising end-tidal carbon dioxide (ETCO2) points toward COPD and BiPAP.
Indications and hard stops
NIV is for the awake patient with pulmonary edema or COPD who can sit up, protect the airway, and cooperate with a mask. It is not for cardiac arrest, a post-ictal coma, or the maybe-they-will-wake-up-in-the-cabin overdose.
Contraindications you must not fly past:
- Vomiting, hematemesis, or a bowel obstruction—NIV is an aspiration machine.
- An unprotected airway or altered mental status (AMS) that will not tolerate the mask.
- Facial trauma, burns, or recent upper-airway surgery that wrecks the seal or the anatomy.
- An untreated pneumothorax—positive pressure can tension it.
- Cardiac or respiratory arrest.
- Copious secretions you cannot clear.
If any of those are present, the airway decision is intubation on the ground, not a tighter mask strap.
In-flight practicalities: leak, power, oxygen, and the bridge
A helmeted, bearded, or restless patient leaks. Every leak dumps pressure and dumps oxygen into the cabin. Reseat the mask, try a different size, or abandon NIV. You cannot hear a leak over rotor noise—watch the leak graphic, the chest, and the saturation. If you cannot sit the patient up in a 24-inch rotor cabin, you may not have an NIV patient.
NIV and HFNC are oxygen-consumption problems. A BiPAP running a high fraction of inspired oxygen (FiO2) or an HFNC at 50 L/min will empty portable tanks far faster than a nonrebreather. Calculate duration before launch. If the numbers do not reach the receiving pad with a reserve, NIV is not a transport plan.
Power matters. A turbine NIV device on battery and a compressor that needs aircraft inverter power fail at different times. Know which failure dumps the patient to room air. Carry a bag-valve mask. A dead battery at 3,000 feet is an unplanned rapid sequence intubation (RSI) in the worst possible room.
Bridge versus you should have intubated
NIV is a bridge when the physiology is reversible on a short clock: nitroglycerin and CPAP for flash edema, bronchodilators and BiPAP for COPD, a short hop to a catheterization laboratory. NIV is a delay when the patient is tiring, the pH is crashing, the mask will not stay on, or the cabin will steal your only easy look. If you would not trust this mask for forty minutes of vibration, intubate on the ramp.
Do not launch a failing NIV patient to save scene time. A tube on the ground is cleaner than a vomit-filled mask at 3,000 feet. Recheck work of breathing, mental status, and the waveform after loading; if the patient is still using accessory muscles or is becoming sleepy, you do not have a bridge—you have a late airway.
Inhaled pulmonary vasodilators for right-ventricular failure belong in Chapter 16; they are not a substitute for deciding whether this mask is even safe.
- Use CPAP for flash pulmonary edema and BiPAP for cooperative hypercapnic COPD.
- Stop NIV for vomiting, an unprotected airway, facial trauma, untreated pneumothorax, arrest, or intolerant AMS.
- Treat HFNC as a hypoxemia tool, not a carbon dioxide tool.
- Do the oxygen and power math before lift.
- Intubate on the ground when NIV is already failing.
Practice these stems in the CFRN practice bank. Emergency-department NIV habits from the CEN study guide still apply—then add tank duration and a mask you cannot hear leak.
Which patient is the best bilevel non-invasive candidate on the ramp?
A vomiting upper-gastrointestinal bleeder with a falling saturation
An alert chronic obstructive pulmonary disease patient with hypercapnic respiratory failure who is protecting the airway
An unconscious opioid overdose with pinpoint pupils and a rate of four
A patient with open midface fractures and blood in the oropharynx
A patient on continuous positive airway pressure for flash pulmonary edema starts vomiting and becoming sleepy. What is the best next action?
Increase inspiratory pressure and strap the mask tighter so alveolar recruitment continues
Switch to high-flow nasal cannula and launch, because high flow will clear the vomitus
Give a midazolam bolus so the patient tolerates the mask for the flight
Remove the mask, protect the airway, and intubate on the ground rather than fly a failing non-invasive patient
What is the biggest operational threat to in-flight non-invasive ventilation when the indication was otherwise correct?
Mask leak, battery failure, and oxygen consumption can silently drop delivered pressure and empty the tanks
Non-invasive ventilation never consumes more oxygen than a nonrebreather, so tank math is optional
Continuous positive airway pressure is contraindicated in flash pulmonary edema, so the device should not be on the aircraft
High-flow nasal cannula is identical to bilevel support for carbon dioxide clearance
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