Elevated liver enzymes in a German tertiary-care hospital: Distribution, diagnostic steps and diagnosis groups.

Background: The determination of liver blood tests is frequently performed in hospitalized patients, and abnormal values require further diagnostics. Yet, analyses considering the management of elevated liver enzymes are missing. Therefore, this study aimed to analyze the distribution of abnormal liver function tests and the subsequent diagnostic steps across different medical specialties.

Methods: From our Hannover liver-injury database, we identified 63,300 cases of patients who were hospitalized between January 2008 and July 2021 with AST or ALT > 3 ULN or AP or TBI > 2 ULN at any time point during hospitalization. Of these, 29,547 cases fulfilled the inclusion criteria and were subjected to further analysis. Cases were analyzed according to the three groups: internal medicine, surgery and others. Analyses were performed regarding baseline characteristics, liver-related diagnostics and factors influencing hospital mortality.

Results: Elevated liver blood tests were mainly observed in internal medicine (n=17,762, 60.1%), followed by the surgery department 34.2% (n=10,105). Notably, 40.2% (n=11,896) developed liver enzyme elevation above the cut-offs during the hospital stay. Testing for hepatitis B and C was more often performed in the surgery department compared to in internal medicine. In total, 5.6% of the cases (n=1,640) had a liver biopsy. Hyperbilirubinemia (total bilirubine ≥ 2ULN) and AST/ALT ratios >2 were associated with in-hospital mortality.

Conclusion: Clinicians are often faced with elevated liver enzymes. However, diagnostic steps differ between different specialties. Physicians should be aware of the increased in-hospital mortality in cases with hyperbilirubinemia or elevated AST/ALT ratios.