Efficacy of peritoneal dialysis in neonates presenting with hyperammonaemia due to urea cycle defects and organic...

Newborns with inborn errors of metabolism can present with hyperammonaemic coma. In this study, we evaluated the effect of peritoneal dialysis on plasma ammonium levels and on the short-term outcome in neonatal patients with urea cycle defects and organic acidaemia.

Data from infants with hyperammonaemia due to urea cycle defects or organic acidaemia treated with dialysis were collected and retrospectively analyzed. The results of patient groups (group I, survived; and group II, died) were compared.

Fourteen neonates were enrolled in this study. In group I, plasma ammonium levels before dialysis were median (IQR) 1652 μg/dL (1165-2098 μg/dL); in group II, they were 1289 μg/dL (1070-5550 μg/dL). There was no statistically significant difference. Urea cycle defects were diagnosed in eight, and organic acidaemia in six patients. The duration of a blood ammonia level >200 μg/dL was longer in group II (P = 0.04). A <60.8% decline in the ammonia level from the beginning of dialysis to the 12th hour of dialysis carried a 3.33-fold higher risk of mortality, when compared with a greater decline. Five patients with urea cycle defects, and one with organic acidaemia, died. The mortality risk was 8.33-fold (95% CI = 0.63-90.86) higher for patients with urea cycle defects than for those with organic acidaemia.

In patients with hyperammonaemia treated with peritoneal dialysis, the rate of ammonia removal and the underlying aetiology appear to be important prognostic factors. Neonates with organic acidaemia who are admitted to centres without continuous renal replacement therapy facilities can be effectively treated with peritoneal dialysis.