Effects of Amino Acid Dialysis Solution on the Nutrition of Continuous Ambulatory Peritoneal Dialysis Patients

Abstract

Objective To evaluate the influence of 1.1% amino acid dialysis solution (AADS) on parameters of nutrition in continuous ambulatory peritoneal dialysis (CAPD) patients. Study Design Studies were performed in 8 men, using AADS for the overnight exchange. Before starting AADS, food intake, nutritional status, and laboratory indices were evaluated and compared to the respective parameters obtained after 3 and 6 months of treatment with AADS, as well as after 3 months of AADS withdrawal. With the start of AADS, doses of antacids were increased and modified during AADS administration; the modified doses were continued through 3 months after cessation of AADS. Another group of CAPD patients using standard dialysis solutions served as controls. In these patients the same parameters were evaluated four times at 3-month intervals. Results Administration of AADS resulted in: (1) 91% absorption of amino acids and improvement of serum amino acid pattern; (2) no change in nutritional intake during the treatment, but after the 3 months of AADS therapy, levels of nutrient intake were lower than those 3 months after withdrawal of AADS with correction of metabolic acidosis; (3) no change in indices of nutritional status, but 3 months after AADS discontinuation, total body weight, lean body mass, and body mass index were significantly higher than those shown after 3 months of treatment; (4) an increase in hemoglobin concentration, hematocrit, BUN, and blood H+. The examined parameters were not significantly changed in patients treated for 9 months with standard dialysis solutions exclusively. The values of nitrogen balance obtained during AADS administration and after 3 months of AADS withdrawal were significantly higher than those obtained in the respective periods in the control group. The blood pH, pCO2, and HCO3– in the last period of the study were higher in the AADS group than in the control group. Conclusion In relatively well-nourished CAPD patients, overnight AADS administration results in increased serum concentration of amino acids without changes in other nutritional parameters. The use of AADS should be associated with increased doses of antacid medication, which abolishes the metabolic effects of acidosis that develop during AADS administration and facilitates positive nitrogen balance.