Use of pure bicarbonate-buffered peritoneal dialysis fluid reduces the incidence of CAPD peritonitis

Background. Advances in bag connection technology have reduced the incidence of peritonitis in CAPD patients but there is little information on the effect of the new peritoneal dialysis fluids. Methods. We studied the incidence of CAPD peritonitis for about 3 years in 100 incident patients-50 patients dialysed with lactate-buffered solution, pH 5.5 and containing glucose degradation products (GDP) (lactate group) and 50 patients with pure bicarbonate-buffered solution, pH 7.4 and low GDP (bicarbonate group). Patients in both groups were similar in age, sex, length of time on CAPD, connection technology and handling of dialysis. Results. In the lactate group, 74 episodes of peritonitis were recorded compared with 43 in the bicarbonate group, i.e. one episode per 21 patient-months with the lactate dialysis fluid and one episode per 36 patient-months with the bicarbonate dialysis fluid (OR 0.58, 95% CI 0.37-0.91, P=0.017). A total of 3369 exchanges per episode of peritonitis were recorded for bicarbonate compared with 2004 exchanges per episode of peritonitis in the lactate group. The majority of organisms isolated in both groups were Gram-positive bacteria, with a predominance of the oropharyngeal and cutaneous endogenous flora. Three episodes of fungal peritonitis occurred in the lactate group and none in the bicarbonate group. Conclusions. Our results suggest that the pure bicarbonate-buffered peritoneal dialysis fluid appears to reduce the frequency of peritonitis in CAPD patients possibly in relation to greater biocompatibility and maintenance of peritoneal membrane structural integrity. Similar results can probably relate to all low-GDP solutions.