Risk Factors and Clinical Features of Ultrafiltration Failure in CAPD Patients; Case-control Study

Yoon, Soo Young; Choi, So Rae; Yoon, Do Sik; Park, Hyeong Cheon; Kang, Shin Wook; Choi, Kyu Hun; Lee, Ho Yung; Han, Dae Suk

Abstract

PURPOSE
Ultrafiltration (UF) failure is one of the most important causes of CAPD withdrawal accounting for up to 20% of CAPD catheter removal. Factors contributing to UF failure are; severe and multiple peritonitis, continuous exposure to nonphysiologic dialysis solution, and use of beta-blockers. We evaluated clinical features of patients with UF failure and assessed the risk factors for UF failure in CAPD patients. METHODS: CAPD data of our institution from Jan 1990 to Dec 2000 were analyzed and a subgroup of 191 patients whose CAPD catheters were removed were collected. Nineteen patients, whose CAPD catheters were removed due to UF failure, were selected from the subgroup as the case group. Seventy-six hospital controls without ultrafiltration failure matched for age, sex, and time of CAPD initiation who were currently maintained on CAPD were selected as the control group. Peritoneal equilibration test (PET) was done within 3 months of initiation of CAPD and at the diagnosis of UF failure, respectively. Peritoneal glucose load was estimated for the first two years. Incidence of peritonitis, accumulated days of peritoneal inflammation (APID), causative organisms of peritonitis, and history of beta-blocker use were evaluated. Peritoneal function was determined by daily net ultrafiltration and mass transfer area coefficient (MTAC) for creatinine. Serum albumin, normalized protein catabolic rate (nPCR) and Kt/Vurea were also evaluated. RESULTS: There was no difference between cases and controls in etiology of ESRD, peritonitis incidence, APID and causative organisms of peritonitis. The case group included more high transporters at the time of the diagnosis of UF failure. The patients with UF failure showed lower nPCR and higher CRP than controls. Serum albumin level was similar at start of CAPD, but decreased faster in UF failure group. Use of beta-blockers and decline in RRF were not different between the two groups. UF fail ure group had higher MTAC for creatinine and more peritoneal glucose load compared to control group. By logistic regression analysis, peritoneal glucose load and increment in glucose load were independent factors associated with UF failure. CONCLUSION: Peritoneal glucose load and increment of glucose load were found to be important risk factors for UF failure in our study. Therefore, various efforts to reduce peritoneal glucose load in CAPD patients are needed for prevention of UF failure.