Incidence of airway fire during laser surgery is traditionally quoted to be ~ 1%, although a large retrospective series of CO2 laser suggested that it may be closer to 0.1%. The data on PVC (clear) vs. red rubber tubes is conflicting. PVC absorbs CO2 lasers (and heats up), which are in the near infrared range, but lets Nd:YAG and visible laser light pass through (although Nd:YAG and other lasers still burn blood and debris). Armored tubes may be a better alternative (ex. Laser Flex [stainless steel spiral] tube by Mallincrodt, Bivona Fome-Cuf [aluminum spiral tube] by Smith’s medical). In lieu of armored ETTs, consider taping (ex. 3M aluminum tape). Also, keep in mind that armored tubes, while more difficult to ignite, can still burn after ~ 6 seconds of laser
While O2 should be minimized, so too should be N2O (which is also highly flammable). Air should be maximized.
Strategies for Preventing Airway Fires
- Minimize oxygen use (and maximize air use)
- Decrease the flammability of the ETT
- Bypass the area being lasered (ex. with a jet ventilator)