Risk Factors and Outcomes of Early-Onset Peritonitis in Chinese Peritoneal Dialysis Patients.

Background/aims: Studies on the risk factors and outcomes of peritonitis within the first 6 months in peritoneal dialysis patients are sparse. This study aims to investigate the risk factors associated with early-onset peritonitis (EOP) and its influence on patients' technique survival and mortality.

Methods: This is a retrospective observational cohort study. A total of 483 patients who had at least one episode of peritonitis were enrolled and followed from March 1, 2002, to August 31, 2016, at our center. According to the time to first peritonitis, we divided patients into two groups: EOP (≤ 6 months, n=167) and late-onset peritonitis (LOP, >6 months, n=316). Logistic regression was used to analyze the factors associated with EOP. A Cox proportional hazards model was constructed to examine the influence of EOP on clinical outcomes.

Results: Of the 483 patients, 167 (34.6%) patients developed their first episode of peritonitis within the first 6 months. The EOP patient group had more male patients, a shorter time on peritoneal dialysis (PD), lower serum albumin levels at the time of PD initiation and a higher peritonitis rate (P<0.05). The EOP patient group had fewer infections with Gram-negative organisms (P=0.013) and more culture-negative peritonitis (P=0.014) than the LOP patient group for the first episode of peritonitis. The multivariate logistic regression analysis showed that factors associated with EOP included male gender (odds ratio (OR) 1.920, 95% confidence interval (CI) 1.272-2.897, P=0.002) and a low serum albumin level at the start of PD (OR 0.950, 95% CI 0.914-0.986, P=0.007). In the Cox proportional hazards model, EOP was a significant predictor of all-cause mortality (hazard ratio (HR) 2.766, 95% CI 1.561-4.900, P<0.001). There were no differences between EOP and LOP for technique failure. However, in continuous analyses, a negative correlation was observed between the time to first peritonitis and technique failure (HR 0.988, 95% CI 0.980-0.997, P=0.006). In the Spearman analysis, the time to first peritonitis was negatively correlated with the peritonitis rate (r=-0.573, P<0.001).

Conclusion: Male gender and a low serum albumin level before PD were strongly associated with EOP. Additionally, EOP patients had a higher risk of poor clinical outcomes. More importantly, an early peritonitis onset was associated with a high peritonitis rate.