Cardioprotective effects of desflurane: Effect of timing and duration of adminstration in rat myocardium

Abstract

Background. We compared the cardioprotective effects of 1 minimum alveolar concentration (MAC) desflurane administered before, during or after ischaemia, or throughout the experiment (before, during and after ischaemia) on myocardial infarct size following 30 min occlusion of the left anterior descending coronary artery and 3 h reperfusion in adult rats. Methods. Fifty male Sprague-Dawley rats were anaesthetized with pentobarbital, intubated and mechanically ventilated. Blood gases, pH and body temperature (37.5-38°C) were controlled. Heart rate and arterial pressure were measured continuously. Animals were randomly assigned to the following groups (n=10 in each group): pentobarbital only ('Pento'); 15 min desflurane administration followed by 10 min of washout before 30 min ischaemia and 3 h reperfusion ('Precond'); 30 min desflurane administration during ischaemia period ('Isch'); desflurane administration during the 15 first min of reperfusion ('Reperf) and desflurane administration throughout the experiment (before, during and after ischaemia; 'Long'). Volumes at risk and infarct sizes were assessed by Indian ink and with 2,3,5-triphenyltetrazolium chloride staining, respectively. Results. Physiological parameters and volumes at risk were not significantly different between groups. In the Pento group, mean myocardial infarct size was 65 (SD 15)% of the volume at risk; myocardial infarct size was reduced to a significant and comparable extent in the desflurane-treated groups (Precond 42 (14)%; Isch 34 (11)%; Reperf 41 (15)%; Long 33 (10)%; P<0.0002 vs Pento group). Conclusions. In rats, desflurane I MAC significantly decreased myocardial infarct size whatever the period and duration of administration. © The Board of Management and Trustees of the British Journal of Anaesthesia 2004.