Chapter 17 - Liver disease

Summary

Introduction

Due to the critical synthetic and metabolic functions of the liver, patients with underlying liver disease are at increased risk of morbidity and mortality during the perioperative period. Previously undiagnosed liver disease is estimated to be present in 1 in 700 otherwise healthy surgical candidates [1,2]. Failure to recognize the presence of underlying liver disease during preoperative evaluation can lead to postoperative morbidity and significantly increased mortality [3]. Identification of these patients prior to surgery will aid in proper risk stratification and management.

Classification of patients with liver disease involves determination of the degree of hepatic damage and the type of abnormality. It is equally important to consider the type of surgery that the patient will undergo. Hepatic complications in the perioperative period may also occur, which are frequently related to use of hepatotoxic medications, development of ischemia, or infection.

Preoperative evaluation

The preoperative evaluation should assess the patient for evidence of acute or chronic liver disease. Special attention should be paid to family history of liver disease as well as risk factors for liver disease such as alcohol abuse, distant receipt of blood transfusions, or illicit drug use. The physical exam should include evaluation for signs of chronic liver disease including spider nevi, temporal and/or muscle wasting, ascites, palmar erythema, and hepatosplenomegaly. Jaundice is rare in the absence of liver pathology (< 1% of patients) and raises concern for more significant liver disease [4]. A careful review of the patient’s blood work may reveal abnormalities suggestive of an underlying liver condition. While many blood tests may reflect liver diseases, the most clinically relevant are the liver enzymes aspartate aminotransferase (AST), alanine aminotransferase (ALT), as well as bilirubin, albumin, and coagulation tests (prothrombin time, INR). Elevation of gammaglutamyltranspeptidase (GGT) or alkaline phosphatase may reflect underlying cholestatic liver disease; however, the significance of their abnormalities during the preoperative evaluation is directly proportional to the finding of other evidence of chronic hepatic dysfunction.