The accumulation of toxic metabolites in children with
inborn errors of metabolism may cause acute metabolic crises and result in long-term neurological dysfunction or death.
Peritoneal dialysis often provides insufficient clearance to protect against these complications, while intermittent haemodialysis cannot prevent reaccumulation of metabolites between dialysis sessions. We describe the use of continuous venovenous haemofiltration (CVVH) or haemodiafiltration (
CVVHD) in three infants with
maple syrup urine disease (MSUD) and one child with
carbamyl phosphate synthetase (CPS) deficiency. All children with MSUD had a satisfactory reduction in
branched-chain amino acids within 24 h of onset of haemofiltration, and are now neurologically normal. The child with CPS deficiency had an
ammonia level of < 100 mumol/l within 24 h of onset of
therapy, but died 3 days later from unrelated cardiovascular complications. Complications of the
therapy included the clotting of one haemofilter and the replacement of two vascular access
catheters per patient on average per
therapy. Two patients required
blood transfusion. We report the successful use of CVVH and
CVVHD in the acute management of metabolic crises associated with
inborn errors of metabolism, and believe that these may be the optimal techniques for the acute clearance of toxic metabolites.