The resistance to carbon dioxide laser ignition of a new endotracheal tube: Xomed laser-shield II

Abstract

Study Objective: To assess the resistance of a new endotracheal tube to penetration and ignition by a carbon dioxide (CO 2 laser at a clinically relevant power setting. Design: An unblinded, in vitro trial simulating clinical conditions. Setting: The operating room at a university medical center. Patients: None. Interventions: A CO 2 laser at 20W with a beam diameter of 1 mm was directed onto the Xomed Laser-Shield II at several points: both perpendicular and tangential to the portion of the tube covered by the protective wrap, to the unwrapped silicone tubing just proximal to the cuff, to the cuff filled with saline and methylene blue, and to the unwrapped silicone tubing distal to the cuff. Trials were performed with or without supplemental oxygen (O 2) blown onto the study site and with a 6 L/min flow through the tube containing one of four concentrations of O 2 in O 2-air admixtures: 21 %, 30%, 40%, and 100%. Measurements and Main Results: Under all conditions, the laser did not penetrate the protective wrap, but the overlying polytetrafuoroethylene (Teflon) sheet was vaporized to an area equal to the size of beam application. The cuff was penetrated by the laser within 5 seconds. The unprotected silicone portion of the tube was penetrated by the laser in approximately 5 seconds, and time to formation of a blowtorch phenomenon shortened with increasing the percentage of O 2 flowing through the tube. Conclusions: The protective coating of the Xomed Laser-Shield II is laser-resistant, but the unprotected silicone proximal and distal to the cuff is laser-vulnerable and can, under certain conditions, promote a blowtorch phenomenon. This tube would be acceptable for use in oral and pharyngeal laser surgery, but we recommend its use only in well-ventilated areas, out of concern for exposure to the products of the pyrolysis of Teflon, specifically the development of polymer fume fever.