#1262 Risk factors of peritoneal dialysis associated peritonitis caused by gram-negative bacteria: a single-center retrospective study over 16 years
Authors: Liang Qichen , Zhao Huiping , Wu Bei , Niu Qingyu , Lu Lixia , Qiao Jie , Men Chuncui , He Yuting , Chu Xinxin , Zuo Li , Wang Mei 
Published: May 2024

Abstract

Background and Aims
To analyse the clinical characteristics, pathogen distribution, and treatment outcomes of peritoneal dialysis associated peritonitis (PDAP) caused by gram-negative bacteria, and explore the risk factors for the occurrence and treatment failure of gram-negative bacterial peritonitis.

Method
We performed a single-center retrospective study included 544 PD patients who underwent regular follow-up between January 1, 2007, and December 31, 2022. After excluding culture-negative peritonitis, fungal peritonitis, and tuberculous peritonitis, based on the pathogens, all episodes were divided into the gram-negative peritonitis group (GNP) and the non-gram-negative peritonitis group (non-GNP). Demographic characteristics, laboratory examinations, pathogenic bacteria, and treatment outcomes were collected and compared between the two groups of peritonitis.

Results
Over the course of 16 years, 297 episodes of peritonitis occurred in 179 patients. Although the overall incidence of peritonitis is showing a year-on-year downward trend, the incidence of GNP has not changed significantly. However, the percentage of GNP cases among all peritonitis cases is on the rise. After excluding episodes of culture-negative peritonitis, fungal peritonitis, and tuberculous peritonitis, a total of 226 cases of peritonitis were included in the study. Among them, females accounted for 50.0%, with an average age of 63.04 ± 11.58 years and a median PD duration of 42 (21, 73) months. Escherichia coli was the main pathogen responsible for gram-negative bacterial peritonitis in our center (37/80, 46.3%), followed by Klebsiella pneumoniae (9/80, 11.3%). The GNP group had significantly higher white blood cell counts in peritoneal effluent on day 0, day 3, and day 5 after peritonitis onset compared to the non-GNP group (p &lt; 0.001 for all). In terms of treatment outcomes, the GNP group had significantly higher rates of developing refractory peritonitis, treatment failure, and peritonitis-associated death compared to the non-GNP group (p &lt; 0.001 for all). Multivariate logistic regression analysis revealed that enteric infection was an independent risk factor for GNP occurrence (OR = 6.315, 95% CI 3.364-11.854, p &lt; 0.001). White blood cell counts on day 3 of peritoneal effluent (OR = 2.666, 95% CI 1.099-6.469, p = 0.030) and post-PDAP blood white blood cell counts (OR = 1.389, 95% CI 1.060-1.820, p = 0.017) were independent risk factors for treatment failure in GNP.

Conclusion
Over the past 16 years, the incidence rate of GNP in our center has shown no significant decrease, and the proportion of GNP cases has been increasing year by year. Escherichia coli is the main pathogen responsible for GNP in our center. GNP cases are more difficult to treat and have a poorer prognosis compared to non-GNP cases. Therefore, it is important to strengthen preventive measures for peritoneal dialysis patients, reduce the risk of enteric infection, and actively treat patients who have already developed gram-negative bacterial peritonitis to avoid adverse outcomes.