Alternative Therapeutic Approach for the Management of Symptomatic Hyperammonemia Syndrome after Lung Transplantation

Purpose Symptomatic Hyperammonemia syndrome after Lung Transplantation (HSLT) is a fatal complication with a mortality rate exceeding 75%. The current management of HSLT consists of a multimodality approach that includes intravenous administration of an ammonia scavenger (Ammonul), with an estimated cost of $93,000 per day. Although the enteral formulation of an alternative ammonia scavenger (Buphenyl) costs far less, at $4,823 per day, its efficacy has not been established for treatment of HSLT. This study evaluated the efficacy of a multimodal approach to management of symptomatic HSLT using Buphenyl as a replacement for Ammonul (Table 1). Methods This was a retrospective chart review analysis of patients who underwent lung transplantation at UFHealth Shands Hospital, from May 01, 2016 till September 30, 2018. Results There were 129 lung transplants performed at UFHealth Shands Hospital during the study period. Six patients developed symptomatic HSLT and required treatment during this timeframe (Table 2). Fifty-percent developed severe neurological symptoms with hemodynamic instability and signs of multi-organ failure. The other 50% presented with altered mental status with no other systemic symptoms. One patient was treated with the Ammonul formula, and the remaining five patients were treated with the Buphenyl formula. All 6 patients were successfully treated with no reoccurrence of HSLT. Examination of etiological work-ups for HSLT, including urea cycle disorders, liver dysfunction, or infectious causes of HSLT were unrevealing. Conclusion The use of Buphenyl, as an alternative to Ammonul, is safe, efficacious, and cost-effective. Early diagnosis and implementation of a multi-modal approach are crucial for successful management of HSLT.