[The effect of the number of peritonitis episodes on peritoneal membrane function].

INTRODUCTION: The problem of an adequate peritoneal dialysis has attracted attention in the recent years. The monitoring and adjustment of intraperitoneal dialysis liquid volume and dialysis duration between the filling and emptying, contributed to individualization of dialysis, improvement of its quality and prolongation of its application. Causes of decline of peritoneal dialyses adequacy have been recently the subject of many clinical studies. The aim of this study was to determine whether the number of peritonitis episodes and duration of treatment with continuous ambulatory peritoneal dialysis (CAPD) influence dysfunction of the peritoneal membrane.

PATIENTS AND METHODS: We analysed 10 patients (4 females and 6 males), aged 27 to 77 years (60.1 +/- 13.9 years), who had been on CAPD for more than two years. All patients were tested at the beginning of CAPD, after one year and after two years of CAPD treatment (using 8 L exchanges per day): dialytic solute urea and creatinine clearance, daily and weekly; KT/V, daily and weekly; residual urea and creatinine clearance; and sum urea and creatinine clearance. The results are expressed as mean +/- SD and the differences between groups were studied by T-test and linear correlation coefficient.

RESULTS: Daily and weekly KT/V declined during time, but was not statistically significant (Table 1). Decline of diuresis influenced the residual and sum creatinine and urea clearance, with no statistical significance (Table 1). Positive correlation was established between decline of diuresis and sum creatinine and urea clearance after one year of CAPD treatment (rcr = 0.7705; rur = 0.7782), as well as after two years (rcr = 0.6332; rur = 0.6852), with statistical significance (p < 0.05). During the first year of the study our patients had 20 episodes of peritonitis (2.00 +/- 1.65) and after two years this number increased to 51 (4.42 +/- 1.72). Negative correlation was evidenced between the number of peritonitis episodes and daily and weekly KT/V, with no statistical significance after one year (rd = -0.2462; rw = -0.2371), but with statistical significance after two years (rd = -0.6332; rw = -0.6852) of CAPD treatment (p < 0.05) (Graph 1).

DISCUSSION: In order to achieve a better prognosis and longer CAPD therapy, we must take into account the patients age, nutrition, catabolism of proteins, residual renal function, and adequacy of dialysis. The consequences of an inadequate therapy can be reflected on morbidity and mortality in these patients. In spite of many discussions, the problem of an adequate peritoneal dialysis, and the value of daily and weekly KT/V are still controversial. Burkat recommends a daily KT/V above 0.24 as adequate and we found this KT/V value as appropriate in one half of our patients. The other authors found that adequate dialysis was achieved with KT/V above 0.29, what we found in two of our patients. The mean daily KT/V was 0.27 at the beginning of the study, and 0.26 after one year of treatment (Table 1); this finding is the the same as in the study of Gotch, and better than reported by Teehan et al. After two years of CAPD the mean daily KT/V was 0.23, what was better than in the study of Teehan et al. Many authors agree that weekly KT/V has to be at least 1.7 for an adequate dialysis; we found the same in one half of our patients in each time interval. Recently, many authors found that the optimal weekly KT/V was over 2, what we found in two of our patients. The mean weekly KT/V at the beginning of the study and after one year of CAPD was above the minimum of adequacy (Table 1). However, after two years of dialysis the mean weekly KT/V was 1.62; this was below the minimum of adequacy. At the beginning of dialysis the residual renal function declines, what we observed in our patients, but without statistical significance (Table 1). The decline of diuresis reflects on the residual and sum creatinine and urea clearance. (ABSTRACT TRUNCATED)