7.4 Non-Invasive Ventilation

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.

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.

CFRN practice bankPractice questions with detailed explanations