OP 1 - Incidence of peritonitis, associated factors, and microbiological spectrum among chronic ambulatory peritoneal dialysis (CAPD) patients at National Hospital, Kandy

Kannangara SK, Abeywardena M, Abeykoon MNational Hospital, Kandy, Sri Lanka

Abstract

Introduction

Peritonitis is a major complication of chronic ambulatory peritoneal dialysis (CAPD), contributing to morbidity and treatment failure. Determining its incidence, microbiological profile, and antimicrobial susceptibility is important for improving patient care and infection prevention.

 Objectives

To determine the incidence of peritonitis, associated factors, causative microorganisms, and antibiotic susceptibility patterns among CAPD patients at National Hospital, Kandy (NHK).

 Design, setting, and methods

A descriptive cross-sectional study was conducted among 167 patients with end-stage renal failure registered at the CAPD

Unit, NHK. Data were collected using an interviewer-administered questionnaire. CAPD fluid samples from patients with clinical features of peritonitis were processed according to standard microbiological guidelines. Organisms were identified by Gram staining, biochemical tests, and the VITEK 2 system for Gram-negative isolates. Antibiotic susceptibility testing followed CLSI-M100 (34th edition) guidelines.

 Results

Among the 167 CAPD patients, 58 developed peritonitis, accounting for 86 episodes during the 7-month study period. The incidence was 0.883 episodes per patient-year (95% CI: 0.70 –1.08). Of these episodes, 57.0% (n=49) were culture-positive and 43.0% (n=37) were culture-negative. No significant associated factors were identified. Diabetes mellitus showed a trend toward increased risk (OR: 1.678, 95% CI: 0.882–3.190), while liver disease showed reduced odds (OR: 0.520, 95% CI: 0.105–2.590). Mean serum bicarbonate levels were significantly lower in patients with peritonitis than in those without (t=2.43, p=0.01). Culture-positive peritonitis was predominantly caused by Gram-positive organisms, mainly coagulase negative staphylococci (CONS) (22.1%, n=19) and Diphtheroids (5.8%, n=5). MRSA was not found.  The most common Gram-negative isolates were Pseudomonas aeruginosa (7.0%, n=6) and Escherichia coli (7.0%, n=6). Gram-positive isolates showed high resistance to penicillin (93.5%, n=29) and amoxicillin (87.1%, n=27), while all remained susceptible to vancomycin, teicoplanin, and linezolid (100%, n=31). Among Gram-negative bacilli, meropenem showed the highest susceptibility (87.5%, n=14), followed by piperacillin–tazobactam (70.6%, n=12).

 Conclusions

CAPD-associated peritonitis remains a significant complication. Lower serum bicarbonate levels were significantly associated with peritonitis. Gram-positive organisms, particularly CONS, were the predominant pathogens. Continuous surveillance, strengthened preventive strategies, and improved diagnostic methods are important for optimizing CAPD care and reducing the burden of peritonitis.