Clinical Analysis of Elevated Serum AST Level in Emergency Patients

ABSTRACT

PURPOSE: Serum aspartate aminotransferase (AST) is an enzyme widly used in the diagnosis of acute liver disease. It is also highly sensitive in cases of myocardial infarction and muscular injury. This study is designed to ascertain the utility of AST for diagnosis in emergency room. METHODS: From July 2001 to September 2002, 98 patients with AST greater than ten times (400 U/L) the normal range were identified by the biochemistry laboratory in the Emergency Medical Center of Chonnam National University Hospital. The patients 'clinical records were studied to determine the diagnosis, the clinical course, the physical finding on arrival, the past history, other serological and imaging studies, etc. RESULTS: The most common cause of elevated AST level was hepatic in origin (74 cases, 75.5%). Other causes were soft tissue injury (13 cases, 13.3%) and myocardial infarction (11 cases, 11.2%). In group with hepatic causes for raised AST, 21 (28.3%) patients had pancreaticobiliary desease, 20 (27.0%) patients were in conditions producing hepatic ischemia, 18 (24.3%) patients had hepatocellular desease, 6 (8.1%) patients had traumatic liver injury, and 4 (5.4%) patients had malignancy. The hepatic ischemia was caused by sepsis (6 cases, 30.0%), heart failure (6 cases, 30.0%), hypoxia (5 cases, 25.0%), and prolonged hypotension (3 cases, 15.0%). CONCLUSION: The main cause of a notably increased serum AST level is known to be hepatocellular disease, but this study for emergency patients revealed that other causes, such as hepatic ischemia, traumatic liver injury, and muscular disease, were also remarkable. When the level of serum AST is abnormally high, the clinician must consider not only hepatocellular disease but also prolonged hypotension, circulatory collapse, hypoxia, traumatic liver injury, etc.