6.4 Airway Complications
Key Takeaways
Unrecognized esophageal intubation is treated by removing the tube and oxygenating—waveform end-tidal carbon dioxide that never appears or fades is esophageal until proven otherwise.
Mainstem intubation, altitude or load dislodgement, and Boyle expansion of an air-filled cuff are flight-specific tube problems; recheck depth and cuff pressure after every climb and move.
Tube obstruction from secretions, kinking, or biting is an oxygenate-first emergency: pass a suction catheter, unkink, bite-block, and replace the tube if the waveform is gone.
Conversion to positive-pressure ventilation can drop venous return and convert a small pneumothorax into tension physiology; treat hypotension and a tense chest immediately.
Can't-intubate-can't-oxygenate means a front-of-neck airway; a false passage after cricothyrotomy has no waveform and a ballooning neck—stop bagging subcutaneous air.
An airway that was correct on the ramp can fail in the climb, the load, or the next five minutes of positive-pressure ventilation. Airway complications on the August 2026 Certified Flight Registered Nurse (CFRN) outline are recognized by physiology, not by hope. Use DOPE—Displacement, Obstruction, Pneumothorax, Equipment—then act. Waveform end-tidal carbon dioxide (ETCO2) that disappears is a crisis until you have a reason it should.
Displacement, cuff, and obstruction
Esophagus, mainstem, load, and rotor wash
Esophageal intubation presents as no waveform (or a waveform that fades in a few breaths), no chest rise, and progressive hypoxia. Immediate action: pull the tube, oxygenate with a two-person bag-valve-mask (BVM) or a supraglottic airway (SGA), then reattempt with a new plan. Do not wait for colorimetric paper.
Mainstem intubation is usually a right-mainstem: asymmetric rise, rising peak pressure, falling saturation, and a depth mark that migrated. Pull the tube back until the waveform and rise equalize. Children mainstem over one centimeter; adults mainstem when the tube slides during a sloppy load.
Dislodgement at altitude and during load is a flight-specific displacement. Stretchers tilt, helmets catch tape, and vibration walks a loosely secured tube out of the glottis. Two people move the patient: one owns the tube. Recheck depth and ETCO2 after the door, after climb, and after every bed transfer. Accidental extubation in rotor wash is the same injury with a crowd. If the tube comes out, oxygenate first, then replace. Cover the face, control the helmet bag, and do not crawl under a running rotor disk to chase a connector.
Cuff leak and tube obstruction
Cuff leak in flight is often Boyle's law. An air-filled cuff expands on climb (risking tracheal ischemia) and loses relative seal on descent. Monitor cuff pressure with a manometer, or fill the cuff with sterile water or saline as your program allows. A leak after descent is not automatically a tube that is too small until you recheck pressure.
Tube obstruction is secretions, kinking against a helmet or rail, or the patient biting. Pass a suction catheter. If it will not pass, unkink, insert a bite-block, and replace the tube if the waveform is gone. A circuit crushed under a seat belt is equipment, not bronchospasm.
| Complication | First clue | Immediate action |
|---|---|---|
| Esophageal intubation | No sustained waveform ETCO2 | Remove the tube; oxygenate; reattempt |
| Mainstem | Unilateral rise, deep depth mark | Withdraw to a mid-tracheal depth |
| Dislodgement / extubation | Waveform lost after a move or climb | Oxygenate; replace; two-person subsequent moves |
| Cuff leak (Boyle) | Leak after descent; rock-hard cuff after climb | Recheck cuff pressure or use a liquid-filled cuff |
| Obstruction | High pressure, catheter will not pass | Suction, unkink, bite-block, replace if needed |
| Tension pneumothorax | High pressure, shock, tracheal shift | Immediate decompression |
| Post-intubation hypotension | Pressure falls after the first breaths | Fluids or blood, pressor, lower intrathoracic pressure |
Soft tissue, failed airway, and positive pressure
Laryngospasm, aspiration, and CICO
Laryngospasm is a sudden closed glottis, often in the lightly anesthetized patient or in the child after suction. Apply a jaw thrust and positive pressure; deepen or paralyze per protocol. If you still cannot move air, you are on a can't-intubate-can't-oxygenate (CICO) clock.
Aspiration is prevented by suction, head-up positioning when the spine allows, and not bagging a stomach full of air. If it happens, suction, secure the airway, and expect desaturation. Do not flood the lungs with a washout. Dental trauma happens when a blade levers on the upper incisors—document broken teeth so they are not aspirated.
Failed airway means your planned attempts have not produced a tube. Stop stacking looks. Oxygenate with BVM or SGA. CICO means you cannot oxygenate either: that is a front-of-neck emergency, not a fourth look.
Positive-pressure shock and surgical-airway mishaps
Converting a spontaneously breathing patient to positive pressure can drop venous return and produce hypotension within a minute. It can also turn a small pneumothorax into tension physiology—especially as cabin altitude rises under Boyle's law. Immediate actions: disconnect and let auto-positive end-expiratory pressure (PEEP) out in the asthmatic, support MAP with blood or a pressor, and decompress a tense chest. Do not give a bigger breath to fix shock.
A cricothyrotomy can bleed, create a false passage, or damage the larynx. In a false passage there is no waveform and the neck insufflates. Stop, withdraw, re-identify the membrane, and do not keep bagging subcutaneous air. Hold pressure for bleeding. Needle airways in small children kink and dislodge; recheck them after every move.
- Lost waveform after a move is displacement until proven otherwise.
- Recheck cuff pressure on climb and descent.
- Suction a high-pressure tube before you assume bronchospasm.
- Treat post-intubation hypotension and tension pneumothorax as positive-pressure injuries.
- CICO means cut; a fourth look is not a plan.
These failure patterns show up in the CFRN practice bank. Shock after conversion to a ventilator is the same physiology the CCRN study guide teaches—then add altitude and rotor wash.
One minute after a reported successful intubation, there is no waveform end-tidal carbon dioxide, the chest is not rising, and saturation is falling. What is the immediate action?
Advance the tube another 4 cm to seat it past the carina
Remove the tube, oxygenate with a bag-mask or a supraglottic airway, then reattempt
Wait for the colorimetric paper to turn yellow on the next three breaths
Clamp the tube to raise mean airway pressure until a waveform appears
During climb in an unpressurized helicopter an air-filled endotracheal-tube cuff becomes rock-hard; after descent a leak appears. What is the best explanation and action?
The tube has kinked against a helmet; cut the tube shorter at the lips
The patient has laryngospasm; deepen narcotic sedation
The tube has migrated into the right mainstem; push it deeper
Boyle's law changed cuff volume with cabin altitude; recheck cuff pressure with a manometer or use a liquid-filled cuff per protocol
After converting a spontaneously breathing asthmatic to positive-pressure ventilation, blood pressure collapses and peak pressures are high. What are the first actions?
Disconnect the circuit to dump auto-PEEP, support mean arterial pressure, and consider tension pneumothorax
Double the respiratory rate to blow off carbon dioxide as fast as possible
Pull the tube immediately because high peak pressure always means esophageal placement
Add more air to the cuff until any leak disappears and then raise tidal volume
Sections you finish are checked off in the contents.