EVALUATION OF A NEW LASER-RESISTANT FABRIC AND COPPER FOIL-WRAPPED ENDOTRACHEAL-TUBE

The risk of an endotracheal tube's combustion during laser airway surg ery necessitates the use of special anesthetic techniques and equipmen t to prevent this complication. This study was designed to evaluate th e Laser-Trach(TM), a new laser-resistant rubber endotracheal tube for use during laser airway surgery.The Laser-Trach endotracheal tubes tha t were evaluated were size 6.0 mm internal diameter (ID) red rubber en dotracheal tubes which had been commercially wrapped by Kendall-Sherid an (Mansfield, Mass.) with copper foil tape and overwrapped with fabri c. The fabric layer was saturated with water prior to our tests, as re commended by the manufacturer, The Laser-Trach endotracheal tubes were compared with plain (bare) size 6.0 mm ID Rusch red rubber endotrache al tubes. The tubes under study were positioned horizontally on wet to wels in air and had 5 L . min(-1) of oxygen flowing through them. They were subjected to continuous laser radiation at 40 W from either a CO 2 or an Nd-YAG laser. The Nd-YAG laser was propagated via a 600-mu m f iber bundle, Each laser was directed perpendicularly at the shaft of t he endotracheal tube being studied, and its output was continued until a blowtorch fire occurred or 60 seconds had elapsed. Sixty seconds of CO2 laser fire did not ignite any of the eight Laser-Trach endotrache al tubes tested, However, blowtorch ignition of all eight bare rubber tubes tested occurred after 0.87 +/- 0.21 (mean +/-SD) seconds of CO2 laser fire, Nd-YAG; laser contact with the Laser-Trach endotracheal tu bes caused the perforation and blowtorch ignition of all eight tubes t ested after 18.79 +/- 7.83 seconds, This was a significantly (P<.05) l onger time than the 5.45 +/- 4.75 seconds required for the blowtorch i gnition of all eight plain rubber endotracheal tubes tested with the N d-YAG laser. Our results show that under the conditions of this study, the shafts of the Kendall-Sheridan Laser-Trach endotracheal tubes wer e resistant to the CO, laser. However, this endotracheal tube is not r ecommended for use with the Nd-YAG laser.