PT - JOURNAL ARTICLE AU - Borrie, Adrienne Elizabeth AU - Pike, Meghan AU - Villeneuve, Stephanie AU - Verma, Neeraj TI - Severe non-hepatic hyperammonaemic encephalopathy in an immunocompromised adolescent with enterocolitis AID - 10.1136/bcr-2023-256225 DP - 2024 Jun 01 TA - BMJ Case Reports PG - e256225 VI - 17 IP - 6 4099 - http://casereports.bmj.com/content/17/6/e256225.short 4100 - http://casereports.bmj.com/content/17/6/e256225.full SO - BMJ Case Reports2024 Jun 01; 17 AB - Non-hepatic causes of hyperammonaemia are uncommon relative to hepatic aetiologies. An adolescent female was admitted to the hospital with a diagnosis of very severe aplastic anaemia. During her treatment with immunosuppressive therapy, she developed neutropenic enterocolitis, pseudomonal bacteraemia and hyperammonaemia. A combination of intermittent haemodialysis and high-volume continuous veno-venous haemodiafiltration (CVVHDF) was required to manage the hyperammonaemia. Despite a thorough investigation, there were no hepatic, metabolic or genetic aetiologies identified that explained the hyperammonaemia. The hyperammonaemia resolved only after the surgical resection of her inflamed colon, following which she was successfully weaned off from the renal support. This is a novel case report of hyperammonaemia of non-hepatic origin secondary to widespread inflammation of the colon requiring surgical resection in an immunocompromised patient. This case also highlights the role of high-volume CVVHDF in augmenting haemodialysis in the management of severe refractory hyperammonaemia.