Usefulness of continuous oxygen insufflation into trachea for management of upper airway obstruction during anesthesia

Background: Severe complications associated with upper airway obstruction o ften occur during the perioperative period. Development of a simple and rel iable technique far reversing the impaired airway patency may improve ah-ma y management. The purpose of the current study is to evaluate the usefulnes s of transtracheal oxygen insufflation (TTI) far management of upper airway obstruction during anesthesia and to explore the mechanisms of TTI in deta il. Methods: During propofol anesthesia in eight spontaneously breathing patien ts, the upper airway cross-sectional area and pressure-flow measurements du ring neck flexion with TTI were compared with those during triple airway ma neuvers (TAM) without TTI. Blood gas analyses assessed efficacy of CO2 elim ination during TTI in an additional nine patients. Results: TTI achieved adequate Pa-CO2 and Pa-O2 levels equivalent to those during TAM. In addition to a significantly smaller cross-sectional area dur ing TTI, the location and slope of the pressure-flow relation during TTI co mpletely differed from those during TAM, indicating that upper airway resis tance was much higher during TTI. Notably, minute ventilation during TTI wa s significantly smaller than that during TAM, suggesting reduced dead space or other mechanisms for CO2 elimination. Conclusions: TTI is capable of maintaining adequate blood gases through mec hanisms different from those of conventional airway support in anesthetized subjects with upper airway obstruction.