Perioperative Risk Management on Remote Organ Injury following Liver Transplantation
Date Issued
2016
Date
2016
Author(s)
Chan, Kuang-Cheng
Abstract
Liver transplantation is the treatment of choice for a variety of irreversible end-stage liver disease. The results of liver transplantation have improved in recent years due to advances in perioperative technique, a better understanding of the course of several liver disease, improved immune-suppressive therapy and more effective postoperative care. However, despite substantial technological, medical and surgical advances, liver transplantation remains a complex procedure that is accompanied by significant morbidity and mortality. The main complications in the postoperative period are related to surgical techniques and systemic medical problems such as pulmonary and cardiovascular complications. The risk of developing early postoperative complications is associated with the patient’s preoperative condition, the quality of the donor and recipient procedure, and perioperative anesthesiological and intensive care management. The morbidity associated with liver transplantation is partly a result of ischemia and reperfusion (I/R) injury. As an anesthesiologist, the first aim of this thesis is to investigate the relationship of oxidative injury and remote respiratory function by an I/R maneuver of the liver in a rat model. Furthermore, we also investigated the commonly seen pulmonary complications following liver transplantation and to determine the relationship between postoperative acute lung injury and extravascular lung water index following liver transplantation by using pulse contour cardiac output (PiCCO) system. The PiCCO system uses the transpulmonary thermodilution technique to determine the cardiac index (CI) and thoracic fluid indices such as the intrathoracic blood volume index (ITBVI), extravascular lung water index (EVLWI), and pulmonary vascular permeability index (PVPI), all of which may reflect pulmonary fluid and injury status. Moreover, to further clarify that whether the thoracic fluid indices are potential risk factors to postoperative ALI, we calculated a multiple logistic regression model which aimed to include possible risk factors in our patients. 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, whereas volatile anesthetics can reduce the oxidative damage through anesthetic preconditioning. The second aim of this thesis is to investigate the different anesthetic strategy on remote lung injury following hepatic I/R and liver transplantation. Cirrhotic cardiomyopathy is a clinical condition in liver cirrhosis consisting of systolic incompetence under condition of stress, diastolic dysfunction related to altered diastolic relaxation, and electrophysiological abnormalities in the absence of any known cardiac disease. The third aim of this thesis is to evaluate the cardiac electrophysiological abnormalities of transplantation candidates with end-stage liver disease by using heart rate multiscale entropy (MSE) before and after liver transplantation. Lastly, we hypothesized that sufficient heart rate variability (HRV, as represented by the deceleration capacity (DC) value) and heart rate complexity (HRC) are suggestive of better cardiac responsiveness and survival for liver transplant recipients. The results of animal research of remote lung injury following hepatic I/R revealed that dynamic compliance was significantly decreased with time after reperfusion, which may be associated with the production of reactive oxygen species (ROS). The results of clinical research of liver transplantation revealed that pretransplant EVLWI and PVPI are higher in recipients who develop postoperative ALI. Monitoring thoracic indices perioperatively may provide clinicians with helpful information facilitating their delivery of postoperative care. The results of clinical research of risk factors of postoperative pulmonary complication following liver transplantation revealed that recipients with the pretransplant PVPI > 1.7 may be at higher risk to develop postoperative ALI. The results of animal research of anesthetic strategy on remote lung injury following hepatic I/R revealed that Propofol infusion was shown to attenuate remote pulmonary dysfunction through an initial reduction of ROS production from the reperfused liver. The results of clinical research of anesthetic strategy on pulmonary complication following liver transplantation revealed that the clinical outcome of the two commonly used anesthetics group were comparable and the ROS production didn’t change significantly during the period of investigation in both groups. The results of clinical research of cardiac electrophysiological abnormalities of transplantation candidates revealed that cardiac electrophysiological alterations in end stage liver disease can be assessed by MSE. MSE may be a more sensitive method to evaluate autonomic dysfunction in end stage liver disease than conventional linear HRV analysis. MSE in patients with MELD score ≧ 25 can improve with no difference compared to MELD < 25 in 7 days. The results of clinical research of HRV analysis in liver transplant recipients revealed that adding cardiovascular biomarkers including DC value and HRC to MELD score improved the ability of the model to predict one-year survival after liver transplantation. Thus, knowledge of complications that emerge during follow up period, early and accurate establishment of diagnosis, and prompt institution of appropriate interventions are essential for optimal patient and graft outcome.
Subjects
Liver transplantation
hepatic ischemia reperfusion
remote organ injury
extravascular lung water index
pulmonary vascular permeability index
Type
thesis
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