Cardiac outcome after sevoflurane versus propofol sedation following coronary bypass surgery: a pilot study

Studies of volatile anesthetic administration during coronary artery bypass grafting (CABG) report reduced serum levels of post-operative cardiac troponin-T (cTnT). Our primary objective was to evaluate whether short-term sedation with sevoflurane in the intensive care unit (ICU)--after CABG--could affect the release of cTnT, compared with propofol sedation.

Following isolated CABG with cardiopulmonary bypass, 100 patients were randomized to either sevoflurane via the Anesthetic Conserving Device (AnaConDa(®)) or propofol for ICU sedation. Study drugs were administered for 2 h during mechanical ventilation and thereafter until extubation criteria were met. The primary endpoint was cTnT 12 h post-operatively. Crude cTnT data were not normally distributed and therefore compared with the Mann-Whitney U-test. Because of the skewed pre-operative and post-operative cTnT data, we performed a post hoc analysis of the change in cTnT between pre-operative values and 12 h post-operatively.

There was no statistically significant difference between groups in the primary endpoint cTnT values at 12 h post-operatively, cardiac events or the need for hemodynamic support. In the post hoc analysis, the cTnT increase from pre-operative values to 12 h post-operatively was less pronounced in the sevoflurane group (P=0.008).

Post-operative short-term sevoflurane sedation following CABG, in comparison with propofol, did not affect the cTnT values at 12 h post-operatively and clinical outcome was equal between groups. The result from the post hoc analysis, with less cTnT change over time, is nevertheless hypothesis-generating and warrants a larger study.