The Child-Pugh and MELD scoring systems predict the risk of surgery for patients with liver disease. The Child-Pugh system requires knowledge of the patient's international normalized ratio (INR), plasma bilirubin level, plasma albumin level, degree of encephalopathy, and volume of ascites. The MELD system uses only creatinine, total bilrubin and INR.
The leading causes of perioperative death or complications for patients with advanced liver disease include hemorrhage secondary to coagulopathy, elevated intracranial pressure, sepsis secondary to peritonitis or pneumonitis, an ascites fluid leak at the site of surgical incision, and acute renal failure secondary to hemodynamic instability or hepatorenal syndrome.
Serious but rare complications of chronic liver disease include the hepatorenal syndrome, the hepatopulmonary syndrome, and portopulmonary hypertension. These may resolve after liver transplantation.
Most forms of chronic liver disease lead to cirrhosis, a histologic diagnosis that is characterized by fibronodular hyperplasia leading to compression and obstruction of sinusoidal capillaries and bile canaliculi. These histologic findings account for the development of portal hypertension that is manifested by ascites, esophageal varices, and hypersplenism.
Inflammatory cellular mechanisms play a role in the development of most forms of liver disease. Inflammatory mechanisms initiate hepatocellular dysfunction, hepatocyte necrosis, and portal fibrosis.
Laboratory testing for the evaluation of liver disease includes tests of synthetic function (INR, serum albumin, and other serum proteins), excretory function (plasma bilirubin levels), and metabolic function (blood glucose, cholesterol, lipoprotein levels), as well as evaluation of bile duct obstruction (plasma alkaline phosphatase) and hepatocellular injury (plasma aspartate aminotransferase and alanine aminotransferase levels). Ultrasonography, computed tomography, and magnetic resonance imaging contribute to establishing an anatomic cause of liver dysfunction.
Transmission of viral infection by means of blood product administration has become rare because of routine immunologic and molecular screening of donors for various infectious diseases. Transmission to health care workers continues to be a hazard because of the lack of immunization against hepatitis C. Health care workers who are carriers of hepatitis B or C should limit the risk of transmitting their disease to their patients.
Nonalcoholic fatty liver disease is emerging as a leading cause of liver disease in the United States. Its prevalence is tied to the frequency of type 2 diabetes and the increasing problem of morbid obesity.
Preoperative attention to the control of ascites, correction of coagulopathy, control of encephalopathy, optimization of renal and pulmonary function, and reduction in the risk of sepsis will decrease the risk of postoperative complications and improve survival rates after surgery in patients with liver disease.
Anesthesia-related drugs such as sedatives and vasopressors should be used with increased caution in patients with liver disease. Benzodiazepines may unmask a subclinical encephalopathy. Vasopressors may decrease total hepatic blood flow, inducing ischemia and potential acute liver failure.
The liver is a unique vital organ because it serves multiple, independent functions, each of which is necessary for sustaining life. These include synthesis of proteins required for coagulation (fibrinogen, prothrombin, factor VII) and fluid volume homeostasis (albumin), conjugation and excretion of ...