CONTINUOUS VENOVENOUS HEMODIAFILTRATION IN THE ACUTE-PHASE OF NEONATAL MAPLE-SYRUP-URINE-DISEASE

Maple syrup urine disease results in accumulation of leucine and its m etabolites, which may lead in the long term to neurological dysfunctio n. In acute neonatal crises, large amounts of leucine may be removed b y continuous venovenous haemofiltration. This extracorporeal technique has its risks and hazards, which increase with duration of treatment. We report three neonates in life-threatening conditions due to maple syrup urine disease, treated for not more than 12h with various contin uous venovenous techniques: continuous haemofiltration, haemodiafiltra tion and haemodialysis. The efficiency of and tolerance to these techn iques was evaluated. For all three patients, plasma leucine levels dec reased dramatically from 2186, 3818 and 2536 mu mol/L to 1131, 1275 an d 488 mu mol/L, respectively. Leucine clearance obtained was 4.28 ml/m in in haemodiafiltration. Their patients' neurological status improved rapidly and they have a normal developmental quotient at 22 months, 1 3 months, and 11 months of age, respectively. Tolerance was good excep t for hypothermia and drop in haematocrit in all cases. Haemodiafiltra tion management was more cumbersome and time consuming because it requ ired continual adjustment of the substitution fluid flow rate to preci sely balance inflow and outflow rates. We recommend continuous venoven ous haemodialysis as the therapy of choice. It might be anticipated th at improvement of this technique, by increasing dialysate flow rate an d blood flow rate, will allow leucine concentration to be decreased be low 1000 mu mol/L within 6-8h, whatever the initial level.