Tissue effects from laser-induced endotracheal tube fires

With the use of the CO₂ laser for endoscopic laryngeal surgery there have been reports of laser ignited endotracheal tube fires. These fires were quickly extinguished, and the extent of injury to the upper airway was evaluated by direct laryngoscopy and bronchoscopy. However, the extent of the injury to the lungs or bronchi could not be determined. Recent experience has shown that the CO₂ laser has become a popular tool for laryngeal endoscopic surgery. Many new instruments have been designed to facilitate precise careful laser surgery. As the use of the laser continues to increase, the chance for accidental laser ignition of an endotracheal tube will increase also. Others have examined the effect of laser energy impacted on endotracheal tubes in vitro. However, no information is available on the laser ignition of endotracheal tubes in vivo. A study was undertaken to examine the injury from laser ignited endotracheal tubes in the canine larynx, distal bronchi and lungs. Three endotracheal tubes were tested; the Rusch red rubber, the PVC polyvinylchloride and silicone. Two types of endotracheal tube fires were studied - those produced by extraluminal and those prodcued by intraluminal ignition.