SHM Converge Scientific Abstract ePoster Gallery-Chasing the Waste: Unraveling the Mystery of Non-Cirrhotic Hyperammonemia-Induced Encephalopathy

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A 78-year-old woman with breast and pancreatic cancer developed recurrent episodes of altered mental status after starting capecitabine and a high-protein diet while severely malnourished. During her third admission, she was somnolent, constipated for two days, and had an elevated ammonia level of 126 µmol/L. Extensive workup ruled out infection, metabolic abnormalities, seizures, intracranial pathology, cirrhosis, and portal vein thrombosis. Brain imaging was unrevealing except for age-related changes, and EEG showed generalized slowing consistent with encephalopathy.<br /><br />She improved rapidly after lactulose enemas, and rifaximin was added to maintain bowel movements and prevent recurrence. She was discharged on both therapies without further episodes.<br /><br />The case highlights non-cirrhotic hyperammonemic encephalopathy as a rare but important complication of fluoropyrimidine chemotherapy, including capecitabine. Reported risk is low but recognized, and episodes are often triggered by factors such as constipation, dehydration, infection, muscle loss, or increased protein load. In this patient, the combination of capecitabine, severe malnutrition, constipation, and a high-protein diet likely created the “perfect storm” for ammonia accumulation and encephalopathy.<br /><br />The authors emphasize the need for a thorough diagnostic evaluation in any non-cirrhotic patient with hyperammonemia to identify reversible causes and distinguish drug-related toxicity from other etiologies.

Asset Subtitle

Karishma D. Narain

Meta Tag

Author List Anesha White, Craigh Bryan, Danielle Pope, Devon Scott, Karishma D. Narain, Kemar O. Barrett, Rayan Elhag, Tanganyika Barnes, Youran Gao

Category Clinical Vignettes

Concept Non-cirrhotic Hyperammonemic Encephalopathy

Concept Hyperammonemia

Concept Altered Mental Status

Concept Fluoropyrimidine

Concept Capecitabine

Distinguished Non-Finalist

Presenter Organization Englewood Health

Presenting Author Karishma D. Narain

Track Adult

Keywords

capecitabine

hyperammonemia

encephalopathy

non-cirrhotic

fluoropyrimidine toxicity

breast cancer

pancreatic cancer

lactulose

rifaximin

malnutrition

Non-cirrhotic Hyperammonemic Encephalopathy

Hyperammonemia

Altered Mental Status

Fluoropyrimidine

Capecitabine