Assessing patients with liver disease for surgery is one of the most common reasons for hepatology consultation in the hospital. This review focuses on practical aspects of evaluating patients with known or suspected liver disease and provides guidance for determining whether it is safe to proceed with surgery in such patients. I begin with a case study to introduce some common clinical challenges and then revisit the case—with relevant teaching points—at the end.
CASE: A MIDDLE-AGED MAN WITH LIVER DISEASE SCHEDULED FOR CARDIAC SURGERY
A 57-year-old man with a history of liver disease is referred for preoperative assessment. It is 6:30 pm, and the patient has just arrived in the hospital; he is scheduled for coronary artery bypass graft surgery (CABG) early tomorrow morning for ischemic heart disease. Ten years ago, he was diagnosed with hepatitis C virus infection; 2 years later, he had a cholecystectomy. He has a remote history of intravenous drug use.
The sub-intern asks for an assessment of operative risk as well as advice on the type of anesthesia to be used.
HEPATIC EFFECTS OF ANESTHESIA
Anesthesiologists are keenly aware of the hepatic effects of anesthesia and that they must carefully choose anesthetics for patients with liver disease. There are a number of at least theoretical concerns about using particular anesthetics:
- Inhaled anesthetics, such as isoflurane, cause systemic vasodilation and depress cardiac output. These effects are of concern since many patients with advanced liver disease already have a hyperdynamic circulation because of peripheral vasodilation.
- Spinal or epidural anesthetics may reduce mean arterial pressure, which is of concern for similar reasons.
- Nitrous oxide has less of a depressive effect unless the patient has concomitant hypercapnia.
Another consideration is the hepatic metabolism of anesthetic agents. Use of halothane, which is 20% metabolized by the liver, is now uncommon, particularly if there is any concern about liver disease. In contrast, enflurane is only 4% metabolized by the liver. Numerous other anesthetics—including isoflurane, desflurane, and sevoflurane—have only minimal hepatic metabolism (< 0.2%), which makes them, along with nitrous oxide, the best anesthetic choices for patients with liver disease.
ASSESSING OPERATIVE RISK
The more important issue in the consultation for our patient is the degree of operative risk associated with his underlying liver disease. A number of factors are pertinent, including the etiology and severity of the liver disease and the type of surgery planned.
Acute liver disease has higher operative risk
Literature dating back 40 years has associated acute viral and alcoholic hepatitis with poor outcomes in surgical patients. Major elective surgery for a patient with suspected acute hepatitis A, for example, should be deferred until the patient has recovered, barring some compelling reason for greater urgency, such as a perforated viscus.