Fatal hyperammonemia after orthotopic lung transplantation.

BACKGROUND

A case of fatal hyperammonemia complicating orthotopic lung transplantation was previously reported.

OBJECTIVE

To describe the incidence, clinical features, and treatment of hyperammonemia associated with orthotopic lung transplantation.

DESIGN

Retrospective cohort analysis.

SETTING

Academic medical center and lung transplantation center in Philadelphia, Pennsylvania.

PATIENTS: 145 sequential adult patients who underwent orthotopic lung transplantation.

MEASUREMENTS: Plasma ammonium levels.

RESULTS

Six of the 145 patients who had had orthotopic lung transplantation developed hyperammonemia, all within the first 26 days after transplantation. The 30-day post-transplantation mortality rate was 67% for patients with hyperammonemia compared with 17% for those without hyperammonemia (P = 0.01). Development of major gastrointestinal complications (P = 0.03), use of total parenteral nutrition (P < 0.001), and lung transplantation for primary pulmonary hypertension (P = 0.045) were associated with hyperammonemia.

CONCLUSIONS

Hyperammonemia is a potentially fatal event occurring after orthotopic lung transplantation. It is associated with high nitrogen load, concurrent medical stressors, primary pulmonary hypertension, and hepatic glutamine synthetase deficiency.