Factors that influence awakening in coronary artery bypass graft using propofol and remifentanil

The development of total intravenous anesthesia in coronary artery bypass graft (CABG) surgery has led to increased interest in the use of combination of propofol and remifentanil. Early extubation in post-cardiac surgery reduces the length of stay in intensive care unit and hospital and costs. The purpose of this study is to evaluate which anesthetic factors affect awakening time after anesthesia.

We enrolled twenty patients of ASA physical status II or III, scheduled for CABG in this study. All patients received a standardized propofol/remifentanil anesthesia as an effect site target controlled infusion. We recorded times to awakening and tracheal extubation, duration of cardiopulmonary bypass (CPB) period, total time of anesthesia and operation. Also, we recorded dose of propofol, remifentanil, fentanyl and minimum body temperature during CPB. To predict the factors that affect awakening time as a dependent variable, we considered all measured parameters as independent variables, and analyzed multiple linear regressions.

The mean time responded to verbal command was 216.5 +/- 124.8 minutes after end of surgery. Among several parameters, minimum body temperature during CPB (P = 0.001) and total time of anesthesia (P = 0.003) were considered as significant factors that influence awakening time after CABG.

Minimum body temperature during CPB and the duration of anesthesia influence awakening time after CABG, significantly.