Differential protective effects of anaesthesia with sevoflurane or isoflurane: an animal experimental model simulating liver transplantation.

BACKGROUND: The mechanisms involved in organ protection by volatile anaesthetics are not completely understood. In the liver transplant setting, there is a lack of information in the literature about whether sevoflurane anaesthesia has a superior hepatoprotective effect when compared with isoflurane. OBJECTIVE: To compare the antioxidant and protective effects of isoflurane and sevoflurane. DESIGN: A randomised, comparative, experimental study. SETTING: The study was performed in the Animal Experimentation Unit of Hospital de Clínicas de Porto Alegre, Brazil. Twenty male Wistar rats weighing between 350 and 450 g were randomly assigned to one of two groups. INTERVENTION: Each group consisted of 10 animals that were exposed to one of two different volatile anaesthetics (sevoflurane or isoflurane). In both groups, five rats were used as 'donors' and another five as 'recipients'. In order to evaluate the effects of each anaesthetic agent, the same anaesthetic technique was used during procurement and reperfusion operations. MAIN OUTCOME MEASURES: Samples of the preservation solution were collected during cold ischaemia to measure aminotransferase and lactate dehydrogenase (LDH) concentrations. After 15 min of reperfusion, blood samples were taken to measure the levels of aminotransferases, LDH and thiobarbituric acid reactive substances (TBARS). The concentrations of TBARS, catalase and nitric oxide derivatives were measured in the liver tissue after reperfusion. RESULTS: Rats in the sevoflurane group had significantly lower concentrations of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and LDH in the samples obtained from the preservative solution after 6 h of cold ischaemia (P < 0.05). Serum TBARS concentrations were significantly lower in the group exposed to sevoflurane anaesthesia (P < 0.001). There were no significant differences in the tissue concentrations of TBARS and catalase (P = 0.089 and P = 0.24, respectively). However, the concentration of nitric oxide was significantly higher in the liver tissue of the rats exposed to sevoflurane anaesthesia (P < 0.05). CONCLUSION: These results suggest that sevoflurane anaesthesia seems to have superior protective and antioxidant effects to isoflurane anaesthesia, not only during cold preservation but also in the early phase of liver reperfusion.