A 67-year-old woman with a history of chronic obstructive pulmonary disease (COPD) with a home oxygen requirement of 3 L/min by nasal cannula and coronary artery disease was admitted to the burn unit. She had been involved in a house fire after falling asleep while smoking and dropping her cigarette. She sustained an inhalation injury and was intubated in the intensive care unit (ICU) for 2 weeks before coming to the operating room (OR) for a tracheostomy. The procedure was done using the in situ polyvinyl chloride endotracheal tube. During the procedure, you had trouble maintaining her blood pressure under anesthesia and were reluctant to use pressors due to recent skin grafts. Because she was tolerating only about 0.6% isoflurane and not much midazolam, you added 20% nitrous oxide to her inspired oxygen.

Unfortunately, she suffered desaturation of her SpO₂ and ST segment changes with attempts to further lower the FiO₂. As the airway was entered with electrocautery at the tracheostomy site, a flame was noted that flashed from the tracheostomy. What might have been done to decrease this risk? Now that a fire has occurred, what should be done?

One of the primary responsibilities of the anesthesia provider is the management of the airway, including anticipating the airway problems that may arise during surgery. Airway fires are complications that are both dramatic and critical when they occur. Selecting an anesthetic plan that decreases the risk of fire is one of the first priorities in airway management. If an airway fire does occur, an anesthesia provider must know what to do to minimize harm to the patient.

The risk of fire occurs whenever the fire triad is present. The fire triad consists of an ignition source, fuel, and oxidizer. It must be recognized that these elements are nearly always present in the OR! During head and neck surgery, these elements are not only present but in close proximity. The oxidizer, oxygen or nitrous oxide, is provided by the anesthesiologist through the endotracheal tube into the surgical site. The ignition source is provided by the surgeon, usually in the form of an electrocautery device or laser. The fuel in airway fires may be the endotracheal tube, packing in the airway, and necrotic or charred tissue. If an endotracheal tube is ignited in a patient,
the flow of gas through the tube can create a “blowtorch”-type flame that can injure more distal structures. Fires that occur at tracheostomy sites as the airway is entered have been reported to cause more local injury and flames that enter the OR environment instead of the distal lungs. Oral and pharyngeal procedures performed in children with uncuffed tubes may result in airway fire because of the leak of oxygen-rich gas into the site on surgery.

The endotracheal tube is the fuel source that is most consistently present in the airway. It has been shown that red rubber, polyvinyl chloride, and silicone endotracheal tubes are all flammable at <26% oxygen. To decrease the risk of combustion, anesthesiologists historically wrapped the endotracheal tubes in metal tape. This practice is not often used today because the tape may loosen, thereby exposing areas of the tubing, it does not cover the cuff, and the tubes may kink easily. Commercially available “laser-resistant” tubes are flexible metal tubes that are more resistant to combustion and may be a better choice for airway surgery. However, these tubes are more bulky and may be more difficult to place. The cuff of the endotracheal tube may be filled with methylene blue; in the event of a cuff perforation, the color change will notify the surgeon. The necessity for an endotracheal tube should be discussed with the surgeon as well. Some procedures may be done with intermittent apnea, although this may require a higher FiO₂ during episodes of ventilation.