Feasibility of standard mechanical ventilation with low FiO2 and small endotracheal tubes during laser microlaryngeal surgery

Background. No technique can be considered as a gold standard for ventilation during direct laser CO2 laryngeal microsurgery. We evaluated the feasibility of standard ventilation with laser-safe endotracheal tubes (ETTs) and inspired O2 fraction (FiO2) = 0.21 during direct microlaryngoscopy. Methods. During total intravenous anesthesia, standard mechanical normoventilation was set with FiO2 = 0.21 and 50 mm Hg peak inspiratory pressure limit. If SpO2 was <90% for >2 minutes, FiO2 was increased to 0.3; after 4 minutes it was increased to 0.4; after another 4 minutes, positive endexpiratory pressure (PEEP) could be set at 5 cm H2O; and after another 4 minutes, surgery was stopped if SpO2 remained <90%. Results. We studied 111 consecutive direct microlaryngoscopies on different patients. Four patients (3.6%) suffered minor intraoperative desaturation. Barotrauma was not observed, PEEP was never applied, and surgery was never stopped. Body mass index was independently predictive of the occurrence of intraoperative desaturation. Conclusions. Standard mechanical ventilation with FiO2 = 0.21 through laser-safe ETTs is feasible during direct microlaryngoscopy. © 2009 Wiley Periodicals, Inc.