Emergency Medical Minute

Contributor: Alec Coston, MD Educational Pearls: Hepatic encephalopathy (HE) is defined as a disruption in brain function that results from impaired liver function or portosystemic shunting. Manifests as various neurologic and psychiatric symptoms such as confusion, inattention, and cognitive dysfunction Although ammonia levels have historically been recognized as important criteria for HE, the diagnosis is ultimately made clinically. An elevated ammonia level lacks sensitivity and specificity for HE Trends in ammonia levels do not correlate with disease improvement or resolution A 2020 study published in the American Journal of Gastroenterology evaluated 551 patients diagnosed with hepatic encephalopathy and treated with standard therapy Only 60% of patients had an elevated ammonia level, demonstrating the limitations of ammonia levels However, a normal ammonia level in a patient with concern for HE should raise suspicion for other pathology. In patients with cirrhosis presenting with neuropsychiat