Comparison of Bispectral index-guided propofol and etomidate infusion for Supraglottic airway insertion

Abstract

IntroductionSupraglottic airway devices have become extremely popular for minor therapeutic and surgical procedures. Their insertion requires an adequate depth of anesthesia with suppression of pharyngeal reflexes. Propofol is the most commonly used agent, but has hemodynamic side-effects. Etomidate, although hemodynamically stable, does not suppress pharyngeal reflexes adequately. Moreover, the use of clinical signs to assess the depth of anesthesia has questionable accuracy. Using bispectral index (BIS) monitoring, the hypnotic component of the anesthetic can be measured, with values of 40–60 implying adequate depth of anesthesia. MethodsThis randomized controlled trial included 80 ASA I patients, divided into two groups of 40 patients. Each group received either propofol or etomidate infusion, with BIS monitoring. At BIS 50, infusions were stopped and SGA was inserted. Changes in hemodynamic parameters, time for SGA insertion, number of attempts, and SGA insertion scores were recorded. ResultsWhen BIS reached 50, a statistically significant fall in mean arterial pressure was observed in the propofol group. Time for SGA insertion was less in the propofol group (30.7 ± 8.0 s), with successful SGA insertion observed in 92.5% of patients on the first attempt, compared with 47.9 ± 9.1 s and 32.3% in the etomidate group. ConclusionIn comparison with etomidate, the use of propofol is associated with better conditions for SGA insertion but has the side-effect of hypotension, even with BIS-guided titration of dose for maintaining an adequate depth of anesthesia.