Desflurane preconditioning in coronary artery bypass graft surgery: a double-blinded, randomised and placebo-controlled study

Abstract

Background: Recent clinical and experimental data indicate that volatile anaesthetics may precondition myocardium against ischaemia and infarction. The present clinical trial was designed to verify the cardioprotective effects of desflurane in patients undergoing elective coronary artery bypass surgery. It was hypothesized that desflurane preconditioning would decrease postoperative release of troponin I and brain natriuretic peptide (NT-proBNP). Besides, we have hypothesized that desflurane preconditioning would preserve the myocardium from the dysfunction following cardioplegic arrest.

Methods: Twenty-eight patients were randomly divided into two groups: Control group (14 patients) and Desflurane group (14 patients). In Desflurane group (DS) patients, preconditioning was elicited after the onset of cardiopulmonary bypass via a 5-min exposure to desflurane (2.5 minimum alveolar concentration), followed by a 10-min washout before aortic cross-clamping and cardioplegic arrest. The control group (C) patients underwent an equivalent period (15 min) of pre-arrest desflurane-free bypass. Haemodynamic measurements were obtained at six different times. The biochemistry markers of cellular damage and myocardial dysfunction (troponin I, NT-proBNP) were determined. Left ventricular (LV) function was assessed using tissue Doppler imaging (TDI) of mitral annulus. Two-factor repeated-measures analysis of variance was used to evaluate differences over time between groups for all parameters determined in plasma samples and for all TDI-derived variables.

Results: After surgery, both the troponin I values (2.04+/-1.09 ng/ml vs 1.44+/-0.77 ng/ml, p<0.01 after 24h and 1.62+/-0.96 ng/ml vs 1.00+/-0.24 ng/ml, p<0.01 after 72 h respectively) and those of the NT-proBNP (2187+/-282.9 ng/l vs 885.4+/-117.35 ng/l, p<0.01 after 24h and 3097.9+/-226.2 vs 1393.6+/-312.07 ng/l, p<0.01 after 72 h respectively) were less in the desflurane-treated patients. The values of TDI of mitral annulus were constantly better in desflurane-treated patients.

Conclusions: We can conclude that the use of desflurane in these patients provides a pharmacological preconditioning so as to reduce myocardial necrosis and improve the cardiac performance in the postoperative period.