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.
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?
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?
After converting a spontaneously breathing asthmatic to positive-pressure ventilation, blood pressure collapses and peak pressures are high. What are the first actions?