Adequacy of Dialysis in Automated Peritoneal Dialysis: A Clinical Experience

Abstract

Objectives To compare the peritoneal clearances of urea and creatinine in continuous ambulatory peritoneal dialysis (CAPD) with three types of automated peritoneal dialysis (APD): continuous cycling peritoneal dialysis (CCPD), 50% tidal peritoneal dialysis (TPD), and 25% TPD and to assess the usefulness of the peritoneal equilibration test (PET) in predicting peritoneal clearances in overnight APD. Patients Eleven uremic patients (mean age 44.5 ± 15.45 years with a mean time on dialysis of 42.63 ± 25.62 months) were included in the study. Measurements PET for urea and creatinine following Twardowski's method. Peritoneal clearances for urea and creatinine CAPD: samples of blood and dialysate within 24 hours. APD: blood mean levels of urea and creatinine before and after nighttime dialysis. Dialysate: urea and creatinine in nocturnal and daytime dialysate. Results Peritoneal clearance of creatinine was 38.14 ± 9.99 L/week/1.73 m2 in CAPD, 44.28 ± 12.4 L/week/1.73 m2 in CCPD, 50.07 ± 17.86 L/week/1.73 m2 in 50% TPD (p < 0.05) and 40.18 ± 6.65 L/week/1.73 m2 in 25% TPD. Peritoneal clearance of urea improved significantly in the three modalities of APD: 51.91 ± 12.58 L/week/1.73 m2 in CAPD; 66.7 ± 9.9 L/week/1. 73 m2 in CCPD (p < 0.05); 76.3 ± 14.5 L/week/1. 73 m2 in 50% TPD (p < 0.001) and 64.3 ± 11.4 L/week/1.73 m2 in 25% TPD (p < 0.05). The dialysatel plasma (DIP) ratio of creatinine at 30,60, 120,180, and 240 minutes showed significant correlation with nighttime APD clearance. Nevertheless, only the DIP ratio of urea at 30, 60, and 120 minutes correlated with overnight APD clearance. Conclusions A remarkable improvement was observed with APD regarding the clearance of urea mainly when 50% tidal peritoneal dialysis was used, whereas it was less noticeable in the clearance of creatinine. The PET is a helpful tool in predicting overnight peritoneal clearances of creatinine but it is less useful in predicting urea clearance.

Advantages of Tidal Peritoneal Dialysis

“…Much higher dialysis solution volumes were used in high flow rate TPD compared to CCPD (6). Comparisons made with continuous ambulatory peritoneal dialysis (CAPD) revealed similar results (7)(8)(9).…”

The Effect of Small Solute Clearances on Survival of Anuric Peritoneal Dialysis Patients

“…In comparison to CAPD, improved peritoneal clearances of small solutes can be achieved by APD (21). However, such dialysis appears to better achieve urea clearance targets than CCr targets, probably because of the short dwell exchanges and the slow equilibration of creatinine.…”

Automated Peritoneal Dialysis Symposium: Determinants in APD Selection

“…APD has been shown to be advantageous compared to CAPD in reducing complications related to catheter infections and peritonitis, and associated hospitalizations. APD, then, may be a cost-effective alternative to CAPD when considering the total costs of care for such patients (9,22). It has also been suggested that APD therapy is more successful in keeping patients vocationally and socially active, which may justify any higher direct costs associated with this modality (5).…”

“…Peritonitis is the most frequent complication in all forms of PD, although peritonitis rates have fallen steadily, with most PD units achieving a peritonitis rate of 0.5 episodes per 12 patient-months. Early observations provided conflicting reports regarding which modality had lower peritonitis incidence rates, but recent clinical trials have shown a trend toward lower peritonitis rates in APD compared to CAPD (5,22).…”