Anesthetic Methods and Liver Transplantation

Overview

Postoperative pulmonary complications are not uncommon after liver transplantation. They can not only prolong the stay in intensive care unit and in hospital but also increase the morbidity and mortality rate. The underlying mechanisms are multifactorial, however, oxidative stress following hepatic ischemia reperfusion and the ensuing pulmonary leukocyte infiltration play an important part in the pulmonary complications. Various drugs and methods such as ischemic preconditioning have been used to lessen the production of oxidative free radicals following hepatic ischemia reperfusion. The choice of different anesthetic agents could aslo change the degree of production of oxygen species and antioxidant capacity during the operation. Volatile and intravenous anesthetic agents can decrease oxidative injuries through different mechanisms, however, which is better in preventing the pulmonary leukocyte infiltration is still unknown. We attempt the compare the oxidative stress and cytokine level in liver transplant recipients under desflurane or propofol anesthesia to evaluate which kind of anesthetic agent is better in this kind of surgery.

The occurrence of postoperative pulmonary complications after hepatic reperfusion, such as in patients undergoing liver transplantation, is a major concern in the intensive care unit. Not only neutrophil infiltration, but also oxidative injuries, have been demonstrated after intra-operative hepatic ischemia/reperfusion (I/R) management. Previous studies have shown that reactive oxygen species (ROS) paly a major role in the ensuing damage, although I/R-induced remote organ injury is a complex and multifactorial process. Methods to reduce ROS generation, such as ischemic preconditioning, attenuate both liver and lung damage after hepatic I/R. Considering the intra-operative ROS production occurs after hepatic reperfusion , the choice of anesthetics may alter the magnitude of ROS production and the antioxidant capacity. Volatile and non-volatile anesthetics can exert their antioxidant capacity through different mechanisms. Propofol (2,6-diisopropylphenol) has been reported to provide antioxidant capacity by scavenging free radicals. However, volatile anesthetics such as isoflurane, desflurane or sevoflurane can reduce the oxidative damage through anesthetic preconditioning. Several animal studies demonstrate that volatile anesthetics offer more protection against ischemia-reperfusion injury than intravenous anesthetics. On the contrary, intravenous anesthetics may be more protective against sepsis-induced hepatic injury than volatile anesthetics. However, there are few investigations concerning the effects of different anesthetics on remote pulmonary injuries in clinical settings. In this study, propofol and desflurane will be used for the maintenance of anesthesia during liver transplantation. The heart function, respiratory function, liver function, kidney function, the oxidative injuries and inflammatory mediators will be compared between the two groups.