To the Editor:—
Airway fire is an uncommon but potentially damaging complication during tracheostomy. Although the airway fire management protocol calls for immediate removal of the endotracheal tube (ETT), 1we may be faced with a situation of irreversible loss of the airway with removal of the ETT or further thermal or chemical damage if it is left in the trachea. 2
A 54-yr-old woman with obesity (120 kg), congenital heart disease (two previous aortic valve replacements), amiodarone-induced interstitial lung disease, pulmonary hypertension, Cushing syndrome, and recurrent congestive heart failure underwent elective tracheostomy. Anesthesia was induced with 160 mg propofol, 100 μg fentanyl, 8 mg vecuronium, and air-oxygen-desflurane. She underwent ventilation via the existing polyvinyl chloride ETT. Oxygen, 100%, was utilized 5 min before incision of the trachea. The trachea was incised with a scalpel, and hemostasis was achieved with diathermy. Ventilation was then discontinued, the cuff of the ETT deflated, and the ETT was withdrawn until its tip was above the tracheal opening. Further diathermy to a bleeding vessel in the subcutaneous fat resulted in a 10-cm flame jetting from the incision, which was extinguished with placement of moist gauze directly over it. After ensuring that there were no further flames, the endotracheostomy tube was inserted into the trachea without incident, and there was no apparent distal airway burn injury on fiberoptic bronchoscopy. The patient had superficial burns to the skin around the tracheostomy site. After the airway was secured with the endotracheostomy tube, the extracted ETT was inspected and found to be undamaged.
This case illustrates two points regarding tracheostomies. First, use of diathermy in the proximity of a 100% oxygen gaseous environment is contraindicated. Both surgeon and anesthesiologist must be aware of this, communicate with one another, and be vigilant to prevent its occurrence. Second, immediate extubation is not always the best response to tracheostomy fires in every circumstance. When the fire is immediately extinguished, when there is concern about potential loss of the airway, and when there is reason to believe that the ETT is not involved in the fire, then the risk-benefit analysis may favor securement of the airway as a priority, superseding removal of the ETT.
The ETT was not removed at the time because it had already been withdrawn beyond the tracheal incision before the use of electrocautery, and the site of the flame was believed to be the trachea and subcutaneous tissue. The deep tracheostomy wound in this obese patient may have contributed to formation of the fire in the fatty tissue. 3If the ETT had been on fire or if there were any doubt that the fire had not been completely extinguished, we would advocate removal of the ETT without delay. In this patient, the benefits of leaving the ETT outweighed the risk of losing the airway if the surgeon had been unable to insert the endotracheostomy tube because of extensive burn damage to the tracheal incision site. Immediate extubation during any airway fire is appropriate as a general guideline, but the importance of an individualized risk-benefit judgment in patients with potentially difficult airways is emphasized. 2