Late Pharmacologic Conditioning with Volatile Anesthetics after Cardiac Surgery

INTRODUCTION:

The aim of this randomized controlled trial was to
investigate whether volatile anesthetics used for postoperative sedation
have any beneficial effects on myocardial injury in cardiac surgery
patients after on-pump valve replacement.

METHODS:

Anesthesia
was performed with propofol. After arrival in the intensive care unit
(ICU), 117 patients were randomized to be sedated for at least 4 hours
with either propofol or sevoflurane. Sevoflurane was administered by
using the anesthetic-conserving device. Troponin T, creatine kinase,
creatine kinase from heart muscle tissue, myoglobin, and oxygenation
index were determined on arrival at the ICU, 4 hours after sedation, and
in the morning of the first postoperative day (POD1). Primary end
points were cardiac injury markers on POD1. As secondary end points
oxygenation, postoperative pulmonary complications, and ICU and hospital
stay were documented.

RESULTS:

Fifty-six patients were
analyzed in the propofol arm, and 46 patients in the sevoflurane arm.
Treatment groups were comparable with regard to patient demographics and
intraoperative characteristics. Concentration of troponin T as the most
sensitive marker for myocardial injury at POD1 was significantly lower
in the sevoflurane group compared with the propofol group (unadjusted
difference, -0.4; 95% CI, -0.7 to -0.1; P < 0.01; adjusted difference, -0.2; 95% CI, -0.4 to -0.02; P = 0.03, respectively).

CONCLUSIONS:

The
data presented in this investigation indicate that late
postconditioning with the volatile anesthetic sevoflurane might mediate
cardiac protection, even with a late, brief, and low-dose application.