ALBUMIN-BASED SOLUTIONS FOR PERITONEAL-DIALYSIS - INVESTIGATIONS WITHA RAT MODEL

To evaluate albumin, an osmotic agent for peritoneal dialysis, the per itoneal fluid and solute transport were investigated during a 4-h sing le cycle peritoneal dialysis with albumin-based dialysis solutions. Tw o different albumin solutions were used in 15 normal Sprague-Dawley ra ts: isotonic 7.5% albumin solution (ADS 1, n = 7) and a combined 7.5% albumin and 1.36% glucose solution (ADS 2; n = 8). A standard 1.36% Di aneal solution was used to provide control values (n = 6). The rate of the intraperitoneal volume change (Q(v)) was positive during the init ial 90 min with ADS 2 and during the initial 60 min with Dianeal 1.36% solution but negative with ADS 1. The peritoneal bulk flow reabsorpti on rate, Q(a), was similar in all three groups. The estimated rate of transcapillary ultrafiltration (Q(u) = Q(v) + Q(a)) was positive with all three solutions throughout the dialysis. With ADS 1, Q(u) increase d gradually during the initial 90 min and then remained stable, but it decreased with ADS 2 and Dianeal 1.36% solution. Q(u) with ADS 2 did not differ from that with Dianeal 1.36% solution during the initial 60 min, but it was significantly higher during the latter part of dialys is. The value of Q(u) during the last 2 h of dialysis was 0.026 +/- 0. 010 and 0.025 +/- 0.009 ml/min with ADS 1 and ADS 2, respectively, and it was significantly higher than that with Dianeal 1.36% solution (0. 005 +/- 0.007 ml/min; p < 0.017). After 4 h of dialysis, 76.1 +/- 10.2 and 78.8 +/- 11.1% of the initial amount of albumin remained in the p eritoneal cavity with ADS 1 and ADS 2, respectively. Since a positive value of Q(u) was maintained for at least 4 h during dialysis with the two albumin-based solutions and was significantly higher after 4 h of dialysis than with the Dianeal 1.36% solution, and since Q(a) was sim ilar with the three solutions, the present findings indicate that the differences in the Q(v) values are due to the differences in the trans capillary ultrafiltration rate (Q(u)). Furthermore, ADS 2, a solution containing both crystalloid and colloid osmotic agents, resulted in hi gher and more prolonged ultrafiltration than did the conventional gluc ose solution. After 4 h of dialysis, about 20-25% of the initial amoun t of albumin was absorbed, indicating that albumin-based dialysis solu tions may compensate for the protein loss into dialysate in continuous ambulatory peritoneal dialysis (CAPD) patients. The results of the pr esent study may provide useful reference data in the evaluation of alt ernative osmotic agents.