Non-cirrhotic Hyperammonemia—When High Ammonia Is not Always from Cirrhosis

Abstract

Though elevated ammonia is often associated with the presence of intrinsic liver disease, several other causes need to be considered. Elevated ammonia can either be related to increased production of ammonia due to a catabolic state (e.g., protein degradation) or due to decreased clearance. Diagnostic workup of elevated ammonia levels involves consideration of the following questions: (1) Is there evidence of underlying liver disease? (2) Is hyperammonemia due to increased production or decreased clearance of ammonia? (3) Is elevated ammonia simply a bystander to obvious clinical scenarios (e.g., septic shock), or does it imply the need for further workup of unrecognized entities (e.g., urea cycle defect) that need prompt attention?