Continuous ambulatory peritoneal dialysis peritonitis: Microbiology and outcomes

Context: Continuous ambulatory peritoneal dialysis (CAPD) is now a preferred mode of the treatment in patients with end-stage renal disease, but peritonitis remains to be a shortcoming of CAPD. High-culture negativity, emerging drug resistance and peritoneal dialysis (PD)-related morbidity and mortality have been a challenge to tackle. Aims: The present study was taken up to compare the the various culture methods and to identify the spectrum of organisms causing CAPD peritonitis and their outcome. Settings and Design: A prospective, observational, cross-sectional study was conducted at a tertiary care teaching hospital in Hyderabad over a period of 1 year. Subjects and Methods: Dialysate fluid from 100 episodes of clinically suspected peritonitis in 75 patients was processed by conventional centrifuging, water lysis, direct inoculation and addition of centrifuged pellet into brain-heart infusion broth and by automated blood culture system. Identification and antibiotic susceptibility of organisms was done, and the outcome of PD-related peritonitis was analysed. Statistical Analysis Used: The categorical data and continuous data were analysed using the Chi-square test and Student's t-test, respectively. P < 0.05 was considered statistically significant. Results: Of the 100 PD fluids, 87 were culture positive. Automated blood culture systems detected 87 episodes, whereas conventional centrifuge method detected only 53 episodes (P = 0.00001). Peritonitis due to Gram-negative organisms (62.3%) was higher than that of Gram-positive peritonitis (31.1%) and fungi (6.4%). Nineteen per cent episodes were constituted by relapse (9), refractory (4), recurrent (4) and repeat (2) peritonitis. Outcomes were analysed as recovery (77%), catheter removal (15%) and death (2.6%). Conclusions: Direct inoculation of peritoneal fluid into automated blood culture bottles increases the positivity rate and also aids in the early detection of CAPD peritonitis, helping reduce morbidity and mortality of PD patients.