Abstract: SA-PO369
Pharmacologic Management with Sodium Phenyl Acetate/Sodium Benzoate with or Without Dialysis for the Treatment of Hyperammonemia: A Case Study
Session Information
- Genetic and Diagnostic Trainee Case Reports
November 09, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Trainee Case Report
- 1300 Health Maintenance, Nutrition, and Metabolism
Authors
- Saeed Zafar, Zubair Barbacena, Yale University School of Medicine, New Haven, Connecticut, United States
- Papamarkakis, Kostas, Yale University, New Haven, Connecticut, United States
- Besse, Whitney E., Yale University School of Medicine, New Haven, Connecticut, United States
Introduction
Hyperammonemia is an underrecognized indication for emergent renal replacement therapy in patients with inborn errors of metabolism. Duration of hyperammonemia correlates with neurologic consequences: seizures, intracranial hypertension, cerebral edema, and herniation. Dialysis decreases ammonia levels acutely, but has associated risks. Additionally, sodium phenylacetate/sodium benzoate is an FDA approved ammonia scavenger for treatment of hyperammonemia in patients with inborn errors of metabolism. There is no current study comparing the effectiveness of ammonia scavengers and dialysis for the acute management of hyperammonemia in adult patients. We present a case in which both treatments were utilized.
Case Description
The patient is a 21-year-old man with a diagnosis of pyruvate decarboxylase deficiency type A on chronic tube feeds who presented with lethargy after one loose bowel movement. Initial workup revealed a lactic acid of 5mmol/L, ammonia level of 447mmol/L, and creatinine of 0.6mg/dL. On exam, the patient had no focal motor or sensory deficits but was agitated and combative. A central venous line was placed for dialysis access and he underwent 2.5 hours of hemodialysis followed by approximately 12 hours of central venovenous hemodiafiltration, in addition to IV dextrose-containing fluids. The ammonia level fell to 34mmol/L. In consultation with the Genetics service, intravenous sodium phenylacetate with sodium benzoate were started and maintained normal levels of ammonia while his home feeding regimen was adjusted. Two weeks later, the patient was readmitted to the ICU with a similar presentation and serum ammonia level of 338mmol/L. This time, sodium phenylacetate with sodium benzoate was initiated rapidly. Ammonia levels were decreased to 47mmol/L over 7 hours without requiring dialysis.
Discussion
This case highlights the potential effectiveness of sodium phenylacetate/sodium benzoate. These ammonia scavengers combine with amino acids to form alternative products for urinary nitrogen excretion. While therapy with hemodialysis should be pursued, patients with normal renal function may achieve rapid resolution of hyperammonemia with volume resuscitation, feeding, and administration of sodium phenylacetate/sodium benzoate as a low risk and cost-effective treatment strategy.