engleski

Possibilities of cardioprotection with sevoflurane usage

OBJECTIVE. In this study we evaluated a cardioprotective effect of sevoflurane in patients underwent coronary artery bypass grafting on a beating heart with normal or moderately decreased preoperative left ventricular function. METHODS. Study included 40 patients induced in anesthesia with 8 vol.% sevoflurane within high 100% oxygen flow (5 L/min) throughout ten minutes. After this period, patients were randomized by computer program into two groups: sevoflurane group (n=20) in which anesthesia continued with 0.5-2 vol.% end tidal sevoflurane to reach approximately 1 MAC of end-tidal concentration, and propofol group (n=20), in which anesthesia maintained with continuous propofol infusion in doses of 2 to 3 mg/kg/h. Pulmonary artery catheter and thermodilution method used for the consecutive hemodynamic measurements. Cardiac index, heart rate, mean arterial pressure and central venous pressure were measured 5 minutes after induction in anesthesia, on the beginning of ischemia, 15 minutes after ischemia and 15 minutes after sternum closure. Inclusion criteria in study were angiographically verified coronary artery disease and left ventricular ejection fraction equal or higher than 40%. Exclusion criteria were any atrioventricular conduction disturbances ; atrial fibrillation with rapid ventricular response, myocardial infarction within last 6 months, and diabetes mellitus. In statistical analysis, we used t-test for analyzing unequal variance within each group. For analysis between groups and time- points, a two-way analysis of variance (ANOVA) was performed and only p<0.05 was considered statistically significant. RESULTS. There were no differences within group and between groups for the heart rate, mean arterial pressure and central venous pressure during surgery. There were no significant differences in values of cardiac index within sevoflurane group. In propofol group significant decrease of cardiac index was estimated at the beginning of ischemia (p<0.001). Furthermore, there were observed significant between-group differences in cardiac index values on the beginning of ischemia (p=0.002) and 15 minutes after ischemia (p=0.011). CONCLUSION. Usage of sevoflurane anesthesia during coronary artery bypass grafting surgery preserved cardiac function in patients with normal or moderately decreased preoperative left ventricular function comparing with patients treated with propofol. Cardioprotective response can be explained with favorable effect of volatile anesthetics on oxygen balance in myocardium. The effect of myocardial contractility associated with the administration of volatile anesthetics is advantageous during coronary revascularization procedures if the decrease in myocardial oxygen consumption is greater than the regional decrease in myocardial perfusion caused by anesthetic. On that way, volatile anesthetics reduce myocardial needs for oxygen and produce antiischemic effect. Independently of hemodynamic effect, volatile anesthetics have and create important cardioprotective effect during myocardial ischemia and reperfusion. Avoiding or at least attenuating ischemic stress impose on the myocardium is an issue of paramount importance in perioperative period.

Cardioprotection ; Sevoflurane ; Cardiac Anesthesiology

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