Assessment of rate, causative organisms, and pharmacological management of peritonitis among patients on chronic peritoneal dialysis at a tertiary hospital, Limpopo Province, South Africa

Abstract

Introduction: Dialysis-associated peritonitis remains a major peritoneal dialysis (PD) complication. The peritonitis rate is a vital tool for quality control in measuring the performance of PD programs in a facility. This study adopted the definitions, recommendations, and outcomes from the International Society for Peritoneal Dialysis (ISPD) 2022 guidelines. Aim: To assess the rate, causative organisms, and pharmacological management of peritonitis among patients on chronic PD at Tertiary Hospital- Renal Unit (TH-RU), South Africa. Methods: A single-centre, quantitative study using a retrospective descriptive cross-sectional design was performed in TH-RU, from 1st January 2023 to 31st December 2023. It included 121 End-Stage Kidney Disease (ESKD) patients on chronic PD. Medical records or charts of ESKD patients were used to collect the demographic and clinical data, dates of peritonitis infection, causative organisms, and pharmacological treatment given. Data was captured using Microsoft Excel®, and statistical analysis was performed using the Statistical Package for the Social Sciences (SPSS, version 29). Descriptive statistics performed included frequencies, percentages, mean, and standard deviations. Inferential statistics determined the association between demographic characteristics and clinical parameters using Pearson’s chi-square test and t-test. The statistical significance was set at p˂ 0.05 and a 95% confidence interval. Results: The peritonitis rate in TH-RU, for 2023 is 0.64 episodes per patient year. The peritonitis rate varied every season, with the highest peritonitis rate of 0.83 episodes per patient-year observed in Autumn, and the lowest peritonitis rate of 0.48 episodes per patient-year in Spring. A total of 61 peritonitis episodes were observed during the study period. The causative organisms observed out of the 61 episodes were the gram-positive bacteria with 37.7% (n = 23) episodes, followed by 34.4% (n = 21) culture-negative, 26.2% (n = 16) gram-negative bacteria, and 1.64% (n = 1) mycobacteria. The leading pathogens amongst the gram-positive and gram-negative bacteria were coagulase-negative Staphylococcus (CoNS) with 56.5% (n = 13) and Pseudomonas aeruginosa with 37.5% (n = 6), respectively. CoNS was the most frequent amongst the gram-positives, and among all the 61 peritonitis episodes recorded. The empirical treatment was intraperitoneal (IP) Cefazolin 1.5g and Gentamicin 60mg daily for 5-7 days for each peritonitis suspect case. Once the culture and sensitivity results were made available, the subsequent treatment of the most gram-positive peritonitis, due to CoNS, was either cefazolin IP 1g/1.5g daily for 7 days or vancomycin IP 500mg/1g daily for 14 days. Peritonitis due to Pseudomonas aeruginosa was treated with IP Gentamicin 40mg/80mg with either IP Ceftazidime 1g/2g or IP Cefepime 1g/2g at night for 21 days. Of the 56 treatment outcomes noted, there were 46.4% (n = 26) medical cures, 5.4% (n = 3) recurrent,16.1% (n = 9) relapses, 5.4% (n = 3) repeat, 3.6% (n = 2) other episode,14.3% (n = 8) transfers to HD and 8.9% (n = 5) PD-associated death. The Pearson chi-square test results indicated a strong association between peritonitis cases (n = 44) and HIV (p-value 0.004). Conclusion: The peritonitis rate of 0.64 episodes per patient year is higher than the recommended ISPD value (target < 0.40 episodes per patient-year). Therefore, measures must be established to lower the peritonitis rate. CoNS was the most frequently isolated pathogen, suggesting that stringent aseptic technique steps should be applied during PD exchange. The high rate of culture-negatives was more than twice the ISPD target (˂15.0%); therefore, a review of culture techniques is recommended to reduce the culture-negative rates. Generally, the peritonitis treatment at TH-RU followed the current ISPD guidelines.