CAPD with an amino acid dialysis solution: a long-term, cross-over study.
This prospective cross-over study was undertaken to evaluate the safety and efficacy of a 1% amino acid dialysis solution on the nutritional and metabolic changes, plasma amino acid profiles and peritoneal membrane function of patients on CAPD. Six CAPD patients had one exchange a day with two liters of this solution over a six month period. Every month there was a medical examination, anthropometric measurements and dietary inquiry were made, blood biochemistry tests were done. Every three months renal function, peritoneal function, aminograms of plasma and dialysate and nitrogen balance were determined. Data were compared with those obtained one month prior to and three months after withdrawal of amino acid administration. Nitrogen balance, which was negative (-1.3 g/day) became positive (+3.1 g/day). Patients who were already overweight increased in weight, both in fat and lean mass. Plasma cholesterol and triglycerides significantly decreased and the amino acid profile moved towards normal; plasma urea levels increased and pH and bicarbonate decreased slightly but significantly (P less than 0.05). Plasma protein concentrations did not change. All the above parameters turned towards basal values when amino acids were discontinued. We conclude that amino acids can be used as osmotic agents for CAPD since they do not cause toxic effects or impair peritoneal membrane function. Moreover, they can help the nutritional status, provided that an increase in weight is prevented and the slight worsening of systemic acidosis is corrected.