Repeat peritonitis in peritoneal dialysis : A cohort study

Abstract

Introduction: The understanding of the pathophysiological mechanisms of repeat peritonitis, defined as the occurrence of peritonitis more than 4 weeks after the end of appropriate antibiotic treatment for a previous episode involving the same germ, remains limited.

Methods: We studied the outcomes of 26 episodes of repeat peritonitis between 2006 and 2024 (Repeat Group) and compared them with 23 episodes of relapsing peritonitis (Relapse Group) and 84 episodes of peritonitis preceded by 4 weeks or more by another episode with a different organism (Control Group).

Results: The majority of cases of repeat peritonitis are caused by gram-positive organisms (65.5%), predominantly Staphylococcus aureus (38.5%), whereas most episodes of relapsing peritonitis are culture-negative (69.5%), followed by gram-negative bacilli episodes (17.4%).
Exit site infection is significantly associated with PD peritonitis. Gram-positive cocci are responsible for 95.5% of exit site infections, mainly due to Staphylococcus aureus.
In the Repeat Group, 14 (66%) patients achieved primary response, and 10 (47%) of them reached complete cure. After the first episode of repeat peritonitis, 3 (14%) patients had their catheter removed and were transferred to long-term hemodialysis. ; however, the risk of developing relapsing peritonitis was 4.7%, and recurrent peritonitis was 9.5%.

Conclusion: The definition of repeat peritonitis is clear. Despite a favorable outcome with antibiotic treatment, the risk of further episodes of peritonitis remains high, threatening the time on peritoneal dialysis therapy and the life of the patient.

Introduction

Peritoneal dialysis (PD) associated-peritonitis is the most common and dreadful complication of PD.

Outcomes of peritonitis vary considerably from one country to another, ranging from cure with antibiotics (69.0-80.7%), catheter removal (10.8-20.4%), or mortality (1.8-6.0%)(Szeto, 2011).

On the other hand, mortality related to peritonitis was defined and reported differently in 55% of studies, with a prevalence ranging from 10% to 20%(Szeto, 2011)(Fried & Bernardini, 1996)(Ye & Zhou, 2017-06-05)(Hassan & Murali, 2022-11).

The International Society of Peritoneal Dialysis (ISPD) 2022 recommendations clearly define repeat peritonitis as an episode of peritonitis occurring more than 4 weeks after the end of antibiotic treatment for a previous episode with the same organism. In contrast, relapsing peritonitis is defined as an episode of peritonitis occurring within 4 weeks of the end of appropriate antibiotic treatment for a previous episode with the same organism, or a sterile episode, and a recurrent peritonitis as an episode that occurs within 4 weeks after completion of therapy but with a different organism(Li et al., 2022).

Regardless of the type of peritonitis, the occurrence of new episodes suggests persistence of infection and may be associated with an increased risk of infectious complications; the prognosis will depend on how quickly the cause is identified and treated.

The aim of this study is to identify patients at risk of developing repeat peritonitis, to understand the associated factors and to assess the outcomes in order to prolong the survival of the technique and to lower morbidity and mortality.

Materials and methods

Patient Selection

From the 2006 opening of our PD unit until January 2024, 235 patients were recruited in our unit.

All episodes of PD peritonitis during this period were carefully considered. (Figure 1)

Figure 1.Example caption for this image

Data was collected by reviewing the French Language Peritoneal Dialysis Registry (RDPLF) database, as well as each patient’s hospital records.

According to the ISPD guidelines(Li et al., 2022), PD peritonitis was diagnosed when at least two of the following are present : 1) abdominal pain and/or cloudy dialysis effluent; 2) dialysis effluent white cell count > 100/μL or > 0.1 x 109 /L (after a dwell time of at least 2 h), with > 50% polymorphonuclear leukocytes (PMN); 3) positive dialysis effluent culture.

In this study and according to ISPD guidelines , we defined repeat peritonitis as an episode that occurs more than 4 weeks after completion of therapy of a prior episode with the same organism.

In the 18 years of the study period, 378 episodes of PD peritonitis (in 9 389 patient-months of treatment) were recorded in our unit. 26 episodes (6.8%) were repeat peritonitis. The result is compared with 23 episodes of relapsing peritonitis during the same period (the Relapse Group), and 84 episodes of peritonitis which had been preceded by another episode caused by a different organism 4 weeks to 24 months (the Control Group). We excluded culture-negative and polymicrobial episodes while selecting the control episodes.

The demographic characteristics, underlying medical conditions, previous PD peritonitis, catheter removal, and clinical outcome were also examined.

Microbiological investigation

Bacterial culture of the dialysate fluid was performed on Chapman and/or chocolate agar, and on Cystine–lactose–electrolyte-deficient (CLED) and blood agar.

Clinical management

PD peritonitis episodes were treated according to the standard antibiotic protocol of our center at the time, which was systematically modified over time.

We initially administer Ceftazidime and Cefazolin IP or IV, plus an aminoglycoside. Antibiotic regimens for individual patients were modified when culture results were available, and the peritoneal dialysis effluent was regularly inspected. Antibiotic therapy was continued for a total of 14 days for episodes caused by Staphylococcus coagulase negative and 21 days for episodes caused by gram negative bacillus or Staphylococcus aureus.

Primary response was defined clinically as the resolution of abdominal pain, clarification of dialysate on day 5 with antibiotics alone.

Complete cure was defined as complete resolution of PD peritonitis with antibiotics alone without relapse or recurrence within 4 weeks after completion of treatment. The Tenckhoff catheter was removed only after staff discussion. If the catheter is removed, antibiotics are maintained for an additional two weeks . If reinsertion of a new catheter was contraindicated, we consider it as a technique failure and the patient transferred to long term hemodialysis.

Statistical Analysis

Qualitative variables were expressed as numbers and percentages, and compared using the chi-square test. Quantitative variables were expressed either as the mean ± standard deviation (SD)

if the distribution of the variable was normal, and compared using the t student or ANOVA , or as the median with the interquartile range if the distribution of the variable was asymmetric.

Statistical analyses were performed using Jamovi 2.3.21

Results

In our study, 96 patients were included ,with a sex ratio of 1.4 (M/F), while the mean age was 50 ±17,3 years.

While 79,2% of our patients were on Continuous ambulatory peritoneal dialysis (CAPD), 85.4% were autonomous.

Of all our patients, 21 (Repeat Group) developed a repeat peritonitis, 19 patients (Relapse Group) developed relapsing peritonitis, and 56 patients (Control Group) had an episode of peritonitis which had been preceded 4 weeks to 24 months by another episode caused by a different organism.

The baseline clinical characteristics at the time of PD peritonitis of the patients are summarized inTable I. There is no significant difference in the baseline clinical characteristics between groups.

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