A COMPARATIVE STUDY BETWEEN SEVOFLURANE VERSUSPROPOFOL AS A PRECONDITIONING TO PREVENT ISCHEMIAREPERFUSION INJURY IN PATIENTS UNDERGOING LOWER LIMBORTHOPEDIC SURGERIES UNDER TOURNIQUET

Background: Ischemia contributes to the pathophysiology of many conditions faced by anesthesiologists, including myocardial infarction, peripheral vascular insufficiencyias orthopedic surgeries under tourniquet), stroke, and hypovolemic shock. Although restoration of blood flow to an ischemic organ is essential to prevent irreversible cellular injury, reperfusion per se may augment tissue injury in excess of that produced by ischemia alone. Aim of the study: This study aimed at evaluation of the preconditioning effect of sevoflurane anesthesia in reducing ischemia reperfusion injury in skeletal muscle and compare this with propofol anesthesia. Methods: This study was conducted on sixty patients of both sexes, ages between 17 and 25 years, and ASA physical status I II selected from those admitted in the orthopedic department units of Ain Shams University hospitals, who were scheduled for surgical procedures of the lower limb under tourniquet. Informed written consents were taken from all patients after approval of Ain Shams University medical ethics committee. The 60 patients were then randomly allocated into three groups. Group A {sevoflurane }; twenty patients were subjected to sevoflurane for induction and maintenance of anesthesia. Group B {propofol}; twenty patients received propofol for induction and maintenance of anesthesia. Group C {spinal} twenty patients received spinal anesthesia. Blood samples were obtained and analyzed for lactate, pyruvate, glucose and creatine kinase. Results: Blood samples during ischemia showed that the sevoflurane group had a higher levels of lactate and pyruvate while the propofol group showed minimal increase of lactate level and reduced pyruvate level. During ischemia there was no change in glucose level in the sevoflurane group, while the level was reduced in the propofol group. The elevation of the creatine kinase level during ischemia was higher in the propofol group than the sevoflurane group and spinal group. During reperfusion lactate, pyruvate, glucose were significantly higher in sevoflurane group than the propofol group, the creatine kinase level was lower in the sevoflurane group than the propofol group. Conclusion: our results indicate that sevoflurane used as protective drug before skeletal muscle tourniquet induced I/R optimizes interstitial release of energy metabolic substrates (glucose, pyruvate, lactate ) and decrease creatine kinase production. In contrast, propofol seems to impair the energy metabolic response of skeletal muscle to tourniquet-induced I/R. These findings may have some importance for the choice of anesthetics in patients undergoing limb surgery with a tourniquet.