Objectives: To compare the nutritional and biochemical effects of amino acid dialysis to dextrose dialysis in children receiving continuous ambulatory peritoneal dialysis (CAPD).
Design: Prospective randomized crossover study.
Setting: Pediatric Nephrology Unit in a tertiary care, teaching hospital of the University of Toronto.
Patients: Seven children aged 0.7-16.5 years receiving CAPD. All patients had poor linear growth, with 5 patients showing evidence of energy deficit.
Interventions: Each patient received either amino acid or dextrose dialysate for 3 months, then crossed over to the alternate regimen for a subsequent 3 months.
Main outcome measures: Nutritional and biochemical data were obtained on each patient during each dialysis regimen.
Results: Analysis of the patients' nutritional data showed comparable weight gain with both regimens but no significant improvement in lean body mass with either regimen. Appetite improved in most patients during amino acid dialysis. Biochemical data during amino acid dialysis showed a tendency to higher plasma potassium and urea levels with no clinical side effects or worsening of acidosis; however, there was a reduced anion gap and increased total plasma protein, due mostly to a rise in plasma albumin and a smaller increase in immunoglobulins. With the exception of tryptophan, fasting amino acid levels at the start and end of amino acid dialysis did not show any significant change. An interesting phenomenon of early blunting of the rise in amino acid levels, following a single amino acid dialysate exchange, was noticed at the end of the amino acid dialysis period. This newly described phenomenon could have been due to tolerance or hepatic enzyme induction.
Conclusions: Overall amino acid dialysis was comparable to dextrose dialysis with no additional proven nutritional benefit, was equally effective in ultrafiltration and creatinine clearance, and produced no adverse clinical or biochemical effects.