Advantage of rubber over plastic endotracheal tubes for rapid extubation in a laser fire

The occurrence of airway fires during laser airway surgery necessitates the use of special techniques to improve patient safety. For example, it is recommended that the endotracheal tube cuff be inflated with saline. However, in the event of an endotracheal tube fire, the tube must be quickly removed. This study was designed to determine the time necessary for red rubber (RR) or polyvinylchloride (PVC) endotracheal tubes to be removed from a model airway after inflating the cuffs with saline. A model larynx and trachea was suspended vertically. It was intubated with either 7.0 RR or PVC endotracheal tubes. Six milliliters of saline was used to inflate the endotracheal tube cuffs. After inflation, a clamp was used to occlude the pilot tube on the RR endotracheal tubes. A 4-lb weight was then suspended from the endotracheal tube. The time to spontaneous extubation of the model trachea after unclamping the pilot tubes on 12 RR endotracheal tubes was determined. For the PVC endotracheal tubes, the times to spontaneous extubation using the 4-lb weight were determined in 12 endotracheal tubes after cutting the pilot tube and in 12 by maximum aspiration of the saline from the endotracheal tube cuff with a 10-ml syringe. A time of 0.94 +/- 0.10 sec (mean +/- SD) was required for spontaneous extubation of the RR endotracheal tubes after unclamping the pilot tube. For the PVC endotracheal tubes, extubation occurred 3.28 +/- 1.08 and 1.81 +/- 0.60 sec after cutting the pilot tube or deflating the cuff with a syringe, respectively. The mean times for each of the 3 groups were significantly different (p < 0.05) from each other as determined by the ANOVA. This study shows that if PVC endotracheal tubes are used, deflation of the saline-filled cuff by aspiration with a 10-ml syringe is faster than cutting the pilot tube. Unclamping the pilot tube on the RR endotracheal tubes resulted in the fastest time to endotracheal extubation.