Sepsis-Induced Hyperammonemia

Mechanisms and Clinical Significance

Septic shock can impair renal function, reducing ammonia excretion, as noted by the National Kidney Foundation 1, 2
Systemic inflammation and hyperammonemia act synergistically in the development of encephalopathy, according to the European Association for the Study of the Liver 3

Consider hyperammonemia in any septic patient with unexplained neurological symptoms, including confusion, as recommended by the American College of Critical Care Medicine 1, 4
Normal ammonia levels are ≤35 μmol/L (≤60 μg/dL) in adults, as defined by the American Association for Clinical Chemistry 4
Hyperammonemia is defined as ≥50 μmol/L (85 μg/dL) in adults, according to the National Institute of Diabetes and Digestive and Kidney Diseases 4
Levels >200 μmol/L (341 μg/dL) are associated with poor neurological outcomes, as reported by the Neurocritical Care Society 4

For patients with short bowel syndrome and hyperammonemia, arginine supplementation may help correct the condition by supporting the urea cycle, as suggested by the American Gastroenterological Association 1, 5
In severe cases with neurological symptoms, renal replacement therapy (hemodialysis) may be necessary to rapidly reduce ammonia levels, as recommended by the National Kidney Foundation 2
Monitor ammonia levels every 3 hours during acute management, as advised by the Society of Critical Care Medicine 2

Patients with short bowel syndrome are at higher risk due to reduced capacity to manufacture citrulline needed for ammonia detoxification, as noted by the European Society for Clinical Nutrition and Metabolism 1, 5
Concomitant renal impairment worsens hyperammonemia as excess ammonia cannot be excreted, according to the International Society of Nephrology 1, 5