Gram-positive Peritonitis Research Articles

#5871 PERITONEAL DIALYSIS INFECTIONS IN MALTA: AN OVERVIEW OF THIRTEEN YEARS

Abstract Background and Aims Peritoneal dialysis (PD)-related infections are still associated with an increased risk of morbidity and mortality. We describe an overview of PD peritonitis and catheter-related infection (CRI) rates in Malta over a period of thirteen years. Method All patients undergoing PD in Malta from 2008 to 2020 were included. Data from 2008 to 2012 was retrospective (shown as mean), whilst data from 2013 to 2020 was prospective. ISPD guidelines and definitions were followed. Results Study population sizes from 2008 to 2020 were as follows: 137 (2008-2012), 91, 80, 126, 117, 102, 103, 101, and 101 respectively. PD peritonitis rates from 2008 to 2020 were 0.38, 0.31, 0.35, 0.46, 0.43, 0.57, 0.54, 0.43, 0.39, 0.40, 0.46, 0.37, and 0.29 episodes/patient/year respectively. Gram-positive peritonitis episodes predominated, the majority of which were Staphylococcal infections. Methicillin-resistant Staphylococcus aureus (MRSA) rates have overall decreased from 0.03 episodes/patient in 2008–2012 to 0.01 episodes/patient in 2020, to no cases in 2016, 2017 and 2019. Coagulase-negative Staphylococcal (CNS) rates also decreased from 0.26 episodes/patient in 2013 to 0.03 in 2017, 0.11 in 2018, 0.04 in 2019, and 0.08 in 2020. With regards to Gram-negative peritonitis, Pseudomonas rates declined from 0.06 episodes/patient in 2008–2012 to 0.03 in 2018. No cases were recorded in 2016, 2019 and 2020. The rate of Escherichia coli-associated peritonitis was 0.03 episodes/patient/year in 2020, and no cases were found in 2016, 2017, 2018, and 2019. Fungal peritonitis rates varied from 0.03 in 2008–2012 to 0.01 episodes/patient/year in 2013, 2018, 2019 and 2020 with no cases being recorded in 2016 and 2017. CRI rates were as follows: 0.39 (2008-2012), 0.35, 0.91, 0.37, 0.38, 0.25, 0.50, 0.29, and 0.22 episodes/patient/year respectively. The incidence of Gram-negative infections from 2013 to 2020 was 49, 51, 52, 65, 58, 66, 48, 41% respectively, with an average rate of 54%. Gram-positive CRIs were mostly Staphylococcal, peaking in 2014 at 0.38 episodes/patient, down to 0.14 in 2019, and 0.10 in 2020. MRSA rates decreased from 0.15 episodes/patient/year in 2014 to 0.01 in 2018, no cases in 2019, and 0.04 in 2020. CRI Pseudomonas rates have overall improved from 0.12 (2008-2012), to 0.06, 0.09, 0.09, 0.14, 0.03, 0.17, 0.06, 0.04 episodes/patient/year from 2013 to 2020. Conclusion The Maltese PD cohort has been achieving ISPD target requirements. Both PD peritonitis and catheter-related infection rates declined over the last thirteen years. There was no MRSA peritonitis in 2016, 2017 and 2019, no Pseudomonas peritonitis in 2016, 2019 and 2020, no E. coli in 2016,2017, 2018 and 2019 and no fungal PD peritonitis in 2016 and 2017. Overall CRIs were predominantly Gram-negative, but not in 2019 and 2020.

Calculated inflammatory markers derived from complete blood count results, along with routine laboratory and clinical data, predict treatment failure of acute peritonitis in chronic peritoneal dialysis patients

Background & Aims Complete blood count (CBC)-derived inflammatory markers are predictive biomarkers for the prognosis of many diseases. However, there was no study on patients with peritoneal dialysis-associated peritonitis (PDAP). We aimed to investigate the value of these markers in predicting treatment failure of acute peritonitis in chronic PD patients. Methods The records of 138 peritonitis episodes were reviewed and divided into treatment success or failure groups in a single center for 10 years. CBC-derived markers and other routine data were recorded before peritonitis treatment was initiated. Univariate and multivariate regression analyses and the receiver operating characteristic (ROC) curve about the predictors of treatment outcomes were performed. Results Neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), systemic immune-inflammation index (SII), and derived NLR were significantly higher in the failure group. Univariate logistic regression results showed that NLR and PLR were risk factors of treatment outcomes. The backward stepwise multivariate logistic regression results demonstrated that NLR [adjusted odds ratio (aOR), 1.376; 95% confidence intervals (CI), 1.105–1.713; p = .004], PLR (aOR, 1.010; 95%CI, 1.004–1.017; p = .002) were risk factors, but hemoglobin-to-lymphocyte ratio (HLR) (aOR, 0.977; 95%CI, 0.963–0.991; p = .001), and SII (aOR, 0.999; 95%CI, 0.998–1.000; p = .040) were protective factors. A combination of age, PD vintage, Gram-positive peritonitis, staphylococcus aureus, culture-negative, NLR, PLR, HLR, and SII would improve prognostic performance. The area under this ROC curve was 0.85, higher than other factors. Conclusions NLR, PLR, HLR, and SII were associated with PDAP outcomes. Age, PD vintage, NLR, and PLR were significant risk factors in PDAP patients.

Exploration of the correlation between intestinal flora and peritoneal dialysis-related peritonitis.

Peritonitis is a serious complication of peritoneal dialysis (PD). Gut microbiota alterations occur in end-stage renal disease (ESRD) patients. The relationship between the gut microbiota and PD-related peritonitis (PRP) is still poorly understood. It is unclear whether the intestinal flora is involved in the pathogenesis of PRP. We collected fecal samples from PRP patients and normal group (NG) PD patients. 16S rRNA sequencing was used to analyze the gut microbiota of PRP and NG patients while also comparing the gram-positive peritonitis (GPP), Escherichia coli peritonitis (EP) and culture-negative peritonitis (CNP) groups in the subgroup analysis. The demographic data and clinical indicators of all patients were collected. Seventeen PRP patients and 28 NG patients were recruited for this study. The analysis of fecal community diversity with 16S rDNA sequencing showed an obvious change in the microbial structure of PRP patients, where Bacteroidetes and Synergistetes were upregulated at different levels, while Bacilli and Lactobacillus were downregulated at different levels compared to levels in the NG group. In the subgroup analysis, Saccharimonadaceae was significantly increased in the GPP group compared to the EP and CNP group. In addition, decreased gene function associated with metabolic pathways was observed in PRP patients. Bacteroidetes and Synergistetes were the dominant orders in PRP patients. The altered composition of the gut microbiota in PRP patients provided deeper insights into the pathogenesis of PRP, and these biomarkers might be established as potential therapeutic targets that deserve further exploration.

POS-725 DOES EARLY ONSET PERITONITIS ASSOCIATED WITH TECHNIQUE FAILURE AND ALL-CAUSE MORTALITY?

Several studies have shown early peritonitis onset are associated with poor technique survival and increased long-term mortality. However, there was no consensus at this moment to define early versus late onset of peritonitis. Thus, we aimed to look for associated risk factors and outcomes such as technique failure and mortality in incident peritoneal dialysis (PD) patients following first episodes of peritonitis either early onset (EOP) versus late onset (LOP). This was observational retrospective single center study recruiting all incident peritoneal dialysis patients from 1st January 2017 to 31stDecember 2020 and followed up till 30 June 2021. First episode of peritonitis was recorded and divided into EOP and LOP. EOP defined as first onset peritonitis before 6 months after initiating PD while LOP was first onset peritonitis after 6 months of PD. Baseline demographic, clinical and laboratory data were collected. The outcomes were technique survival and all-cause mortality at the end of study period. SPSS Version 26.0 was used to analyze descriptive and categorical data. Total 228 peritonitis episodes were recorded during this study period; 101 cases were first episode of peritonitis. EOP occurred in 39 patients while 62 patients in LOP group. In EOP group, 19 (48.7%) were male, 20 (51.3%) female versus LOP group 38 (61.3%) were male, 24 (38.7%) were female, p=0.15. The mean age between EOP and LOP was 53.2(±12.3) and 54.2(±12.2), p=0.62. The mean duration from PD initiation to first onset peritonitis was 2.2±1.7 months in EOP group compared to 17.0±10.1 months in LOP group, p <0.01. There was no significant difference in demographic, clinical or laboratory data between the groups. There was higher incidence of culture negative in EOP group compared to LOP group, 16/39(41.0%) versus 19/62(30.6%), p=0.22 and gram-negative peritonitis in EOP group, 13/39(33.3%) versus 18/62 (29.0%), P=0.22. LOP group observed higher incidence of gram-positive peritonitis 19/62(30.6%) compared to EOP group 9/39(23.1%), p=0.22. In term outcome, higher rate of catheter salvage in EOP group 32/39 (82.1%) compared to LOP 35/62 (56.5%), p=0.07. There was also higher incidence transfer to hemodialysis (HD) amongst LOP group 17/62 (27.4%) versus EOP group 5/39 (12.8%), p=0.01. Till follow up period, there was no significant difference in Kaplan Meier survival curve in term technique failure and all-cause mortality between EOP and LOP. In our cohort patients, EOP was not significantly associated with technique failure and all-cause mortality as compared to LOP. Higher incidence of PD dropped out following peritonitis episodes in LOP group need further evaluation.

Variation in Peritoneal Dialysis–Related Peritonitis Outcomes in the Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS)

Peritoneal dialysis (PD)-associated peritonitis is a significant PD-related complication. We describe the likelihood of cure after a peritonitis episode, exploring its association with various patient, peritonitis, and treatment characteristics. Observational prospective cohort study. 1,631 peritonitis episodes (1,190 patients, 126 facilities) in Australia, New Zealand, Canada, Japan, Thailand, the United Kingdom, and the United States. Patient characteristics (demographics, patient history, laboratory values), peritonitis characteristics (organism category, concomitant exit-site infection), dialysis center characteristics (use of icodextrin and low glucose degradation product solutions, policies regarding antibiotic self-administration), and peritonitis treatment characteristics (antibiotic used). Cure, defined as absence of death, transfer to hemodialysis (HD), PD catheter removal, relapse, or recurrent peritonitis within 50 days of a peritonitis episode. Mixed-effects logistic models. Overall, 65% of episodes resulted in a cure. Adjusted odds ratios (AOR) for cure were similar across countries (range, 54%-68%), by age, sex, dialysis vintage, and diabetes status. Compared with Gram-positive peritonitis, the odds of cure were lower for Gram-negative (AOR, 0.41 [95% CI, 0.30-0.57]), polymicrobial (AOR, 0.30 [95% CI, 0.20-0.47]), and fungal (AOR, 0.01 [95% CI, 0.00-0.07]) peritonitis. Odds of cure were higher with automated PD versus continuous ambulatory PD (AOR, 1.36 [95% CI, 1.02-1.82]), facility icodextrin use (AOR per 10% greater icodextrin use, 1.06 [95% CI, 1.01-1.12]), empirical aminoglycoside use (AOR, 3.95 [95% CI, 1.23-12.68]), and ciprofloxacin use versus ceftazidime use for Gram-negative peritonitis (AOR, 5.73 [95% CI, 1.07-30.61]). Prior peritonitis episodes (AOR, 0.85 [95% CI, 0.74-0.99]) and concomitant exit-site infection (AOR, 0.41 [95% CI, 0.26-0.64]) were associated with a lower odds of cure. Sample selection may be biased and generalizability may be limited. Residual confounding and confounding by indication limit inferences. Use of facility-level treatment variables may not capture patient-level treatments. Outcomes after peritonitis vary by patient characteristics, peritonitis characteristics, and modifiable peritonitis treatment practices. Differences in the odds of cure across infecting organisms and antibiotic regimens suggest that organism-specific treatment considerations warrant further investigation.

POS-643 PERITONEAL DIALYSIS RELATED PERITONITIS: A SINGLE CENTRE EXPERIENCE IN BORNEO, MALAYSIA

Peritoneal dialysis (PD) - related peritonitis is a common complication and a major cause of conversion to haemodialysis (HD). We aimed to determine the demographic characteristics of our patients, and to evaluate the microbiology and clinical outcomes among PD patients with peritonitis A retrospective observational cohort study enrolling all patients who had been treated with continuous ambulatory PD (CAPD) or automated PD (APD) for at least 90 days and developed peritonitis at Hospital Queen Elizabeth, Sabah, Malaysia from January 2014 until June 2020. Relevant demographic, biochemical and clinical data were collected. A total of 369 episodes of peritonitis were recorded in 194 patients. The median age of patients were 46.41± 16.2 years (range from 8 to 84 years); 85 (43.8%) were male. 71 (36.6%) had diabetes as the primary disease. The overall peritonitis rate was 0.384 episodes per patient-year. Gram-positive organism was the predominant organism from the cultures, 156 episodes (42.28%), followed by Gram-negative organism (88 episodes, 23.85%), fungal (19 episodes, 5.15%), mycobacterium (4 episodes, 1.08%), polymicrobial (5 episodes, 1.36%), and culture negative (97 episodes, 26.29%). Coagulase negative Staphylococcus (CONS) was the most common organism among the gram-positive peritonitis while Escherichia coli was the most common organism in gram-negative peritonitis. The PD catheter were removed in 109 episodes (29.54%). Mycobacterium and fungal had higher risk of catheter loss (100% and 89.5% respectively). The catheter loss rate was significantly higher in gram-negative peritonitis, as compared to gram-positive (38.6% VS 15.4%, p<0.001). Seven patients died due to PD peritonitis (2 from gram-positive, 3 gram-negative, 1 culture negative and 1 polymicrobial). The high rates of culture negative PD peritonitis needs further evaluation and improvement on identification of the organisms. Retraining, exit site care, improved microbiology sensitivity, appropriate antimicrobial treatment and response and early removal of the catheter are warranted to further improve the PD-related peritonitis technique failure and mortality.

Repeat and Relapsing Peritonitis Microbiological Trends and Outcomes: A 21-Year Single-Center Experience.

Peritonitis is a major peritoneal dialysis complication. Despite a high cure rate, relapsing and repeat peritonitis is associated with Tenckhoff catheter biofilm and multiple episodes of peritoneal damage. In relapsing peritonitis, prompt catheter removal is mandatory; otherwise, in repeat peritonitis, there is not a clear indication for catheter removal. It is questionable if the approach to removal should be different. There are few recent data on repeat and relapsing peritonitis microbiology and clinical outcomes since most studies are from the past decade. This study evaluates the microbiology, clinical outcomes, and impact of relapsing and repeat peritonitis on technique survival and the impact of catheter removal in development of further peritonitis episodes by the same microorganism. We developed a single-center retrospective study from 1998 to 2019 that compared repeat and relapsing peritonitis with a control group in terms of causative microorganisms, cure rate, catheter removal, and permanent and temporary transfer to hemodialysis. We also compared repeat and relapsing peritonitis clinical outcomes when Tenckhoff catheter was not removed. Comparing to the control group, the repeat/relapsing group had a higher cure rate (80.4% versus 74.5%, p=0.01) and lower rate of hospitalization (10.9% versus 27.7%, p=0.01). Technique survival was superior in the repeat/relapsing group (log rank = 4.5, p=0.03). Gram-positive peritonitis was more common in the repeat/relapsing group especially Streptococci viridans (43.5% versus 21.3%, p=0.01) and Gram-negatives in the control group (26.6% vs 9.0%, p=0.02). When the Tenckhoff catheter was not removed after a repeat episode, 58.6% developed a new repeat/relapsing episode versus 60.0% in the relapsing group. Although repeat and relapsing peritonitis have a higher cure rate, it leads to further episodes of peritonitis and consequent morbidity. When Tenckhoff catheter was not removed, the probability of another peritonitis episode by the same microorganism is similar in repeat and relapsing peritonitis.

P1224ROLE OF DIAGNOSTIC IMAGING DURING PERITONITIS IN PERITONEAL DIALYSIS PATIENTS

Abstract Background and Aims Peritonitis in peritoneal dialysis (PD) patients can be directly related to PD or secondary to intrabdominal infection (secondary peritonitis). The indication and role of imaging of abdomen during peritonitis in PD patients is unclear. Method This was a single center, retrospective study, including all the first episode of peritonitis in incident PD patients from the period of January 2013 to October 2017. Primary aim of the study was to identify the incidence of secondary peritonitis diagnosed by imaging of abdomen (defined as positive scan finding of intraabdominal lesions) in PD patients with peritonitis. Secondary outcomes were predictors for secondary peritonitis analyzed by multivariable logistic regression. Results There were total 527 incident PD patients during the study period. Of these, 153 patients (29%) developed at least one episode of peritonitis. The mean age of patients with peritonitis was 57.7 ± 3.4 years, 49 % were male, and 52% had diabetes mellitus. Out of 153, 78 patients (51%) underwent diagnostic imaging of abdomen to look for secondary peritonitis. Majority of them had contrast enhanced computed tomography (CT) scan (95%) and the remaining had non-contrast CT scan or ultrasound of abdomen. Of 78 patients who underwent scan, 12 patients (16%) were reported to have intra-abdominal lesions (secondary peritonitis) including colitis (n=2), pancreatitis (n=1), cholecystitis (n=4), appendicitis (n=1), intestinal obstruction (n=2), liver abscess (n=1), gastric cancer (n=1). According to the causative micro-organisms, the positive scan finding of intra-abdominal lesions was more commonly observed in Gram-negative peritonitis (n=7, 58%), followed by fungal/mycobacterial peritonitis (n=2, 17%), Gram-positive peritonitis (n=2, 17%), polymicrobial peritonitis (n=1, 8%), but none (0%) in culture negative peritonitis. Among patients with Gram-negative peritonitis who underwent the imaging of abdomen, only 12% (7/58) were reported to have intra-abdominal lesions. In multivariable logistic regression, the presenting symptoms including fever (odds ratio (OR) 1.51, 95% confidence interval (CI) 0.40 – 5.68), abdominal pain (OR 1.08, 95% CI 0.24 -1.78), presence of cloudy of effluent (OR 0.66, 95% CI 0.19 -2.29), hypotension on presentation (OR 3.61, 95% CI 0.75 -17.46) or effluent white cell counts on presentation (OR 0.99, 95% CI 0.93 -1.05) were not significantly associated with secondary peritonitis. Conclusion A considerable number of patients underwent imaging of abdomen during peritonitis regardless of causative organisms, only a few of them had intra-abdominal lesions. Future prospective study is needed to guide the role of imaging in PD patients during peritonitis.

P1208TREATMENT OUTCOMES IN PERITONEAL DIALYSIS PERITONITIS ARE NOT AFFECTED BY DEGREE OF RESIDUAL RENAL FUNCTION

Abstract Background and Aims Early studies in peritonitis showed no difference in outcomes between anuric and non-anuric patients, despite pharmacokinetic studies showing the effect of residual renal function (RRF) on antibiotic clearance. Recent work identified a relationship between preserved RRF and treatment failure in gram-positive and culture-negative peritonitis. Our centre uses empiric vancomycin and gentamicin dosed by weight (both drugs) and by RRF (gentamicin). We sought to examine whether RRF is associated with treatment failure in our population. Method We retrospectively identified all episodes of PD peritonitis between January 2014 and July 2019 including demographic and clinical information. The RRF measured closest to the peritonitis episode was used. Treatment failure was defined as death, catheter removal or relapse. Results 189 peritonitis episodes occurred in 128 patients (43% female, mean age 61.3±17.9). 80 episodes were caused by gram-positive bacteria, 49 gram-negative, 51 culture-negative, 5 fungal and 4 polymicrobial. 21, 88 and 61 episodes occurred in patients with a creatinine clearance &amp;lt;0.5, 0.5-5, and &amp;gt;5ml/min respectively. Creatinine clearance data was unavailable in 21 patients. Treatment failure occurred in 72 cases (38%) (19 relapses, 52 catheter removals, 7 deaths). Treatment failure for all bacterial peritonitis episodes was not affected by RRF as compared to anuric patients: 0.5-5 (OR 0.41, 95% CI 0.12-1.35, p 0.14) or &amp;gt;5 (OR 0.90, 95% CI 0.22-3.67, p 0.88). There was no difference in outcome in sub-group analysis by type of organism. Antibiotic concentrations did not differ between the RRF groups. Conclusion Although limited by small numbers we found no association between the degree of RRF and outcome. We hypothesise this is because we monitor antibiotic concentrations and therefore dose antibiotics appropriate to the level of RRF. In PD peritonitis regimes that adjust for RRF there is no impact of RRF on treatment outcomes.

P1173PERITONEAL DIALYSIS INFECTIONS IN MALTA - TRENDS OVER ELEVEN YEARS

Abstract Background and Aims Infections related to peritoneal dialysis (PD) are still a cause of morbidity and mortality. We describe an overview of PD peritonitis and catheter-related infections (CRI) in Malta over a period of eleven years. We also describe trends in dialysis modality over the years. Method All patients undergoing PD in Malta during 2008 and 2018 were analysed. Data from 2008-2012 was retrospective, shown as mean, that from 2013-2018 prospective. International Society for Peritoneal Dialysis (ISPD) definitions were used. Results for categorical responses were summarized using absolute numbers and percentages. Medians (range) were used to describe continuous non-normally distributed data. Results The total number of patients undergoing PD from 2008 till 2018 were 137 (2008-2012), 91, 80, 126, 117, 102, 103 respectively. There was an overall male predominance of 63.5% (61-67). Patient years at risk were 85.80, 85.25, 89.71, 83.70, 79.69, 72.88 since 2013 respectively. The overall incidence of diabetes mellitus was 45.3% (41.8-50), cardiovascular disease 34.2% (33.8-35), hypertension 79.3% (73.8-84.6). PD was used in 50% of dialysis modality prior to 2012, 39% in 2018. Initially 51% used Automated PD (APD), with 21% assisted PD, in 2018 39% used APD, with 6% assisted PD. PD peritonitis rates from 2008 were 0.38, 0.31, 0.35, 0.46, 0.43, 0.57, 0.54, 0.43, 0.39, 0.40, 0.46 episodes/patient year respectively There was marked dominance of Gram-positive peritonitis, mainly Staphylococcal, with a reduction of coagulase-negative-Staphylococcus from 0.26 episodes/patient in 2013 to 0.03 in 2017, 0.11 in 2018. Methicillin-resistant S. aureus (MRSA) peritonitis decreased from 0.03 episodes/patient to nil in 2016, 2017, 0.01 episodes/patient in 2018. Amongst Gram-negative peritonitis, Pseudomonas rates decreased from 0.06 to 0.03 episodes/patient in 2018, nil in 2016. Escherichia coli rates decreased from 0.02 episodes/patient to nil in the last three years. Fungal rates from 0.03 to 0.01 episodes/patient/year, with nil in 2016, 2017. Catheter-related infection rates were 0.39 (2008-2012), 0.35, 0.91, 0.37, 0.38, 0.25, 0.50 episodes/patient/year respectively. There was a higher incidence of recurrent infections in 2014, none in 2015 and 2016. Gram-negative organisms accounted for 57% of all CRI, predominantly Pseudomonas at 0.12 (2008-2012), 0.06, 0.09, 0.09, 0.14, 0.03, 017 episodes/patient/year respectively. Gram-positive CRI were mostly Staphylococcus aureus, peaking in 2014 at 0.38 episodes/patient/year. MRSA rates declined from 0.15 to 0.01 episodes/patient/year in 2018. Conclusion PD peritonitis rates in Malta between 2008 and 2018 were below the ISPD recommended threshold. There were no episodes of MRSA in 2016, 2017, no Pseudomonas in 2016, no E coli in the last three years and no fungal PD peritonitis in 2016, 2017. CRI rates also declined, with an overall predominance of Gram-negative infections.

Lipopolysaccharide Evaluation in Peritoneal Dialysis Patients with Peritonitis

Background: Lipopolysaccharide (LPS), also known as endotoxin, is cell wall component of Gram-negative (GN) bacteria, which may contribute to the progression of a local infection to sepsis. Previous studies demonstrate that LBP is detectable in peritoneal effluents of peritoneal dialysis (PD) patients and it is significantly elevated in PD patients with peritonitis caused by both GN and Gram-positive (GP) bacteria. Aim: The aim of this study was to evaluate LPS levels in PD patients; in particular, we investigated different LPS levels in the context of GP and GN peritonitis. Material and Methods: We enrolled 49PD (61% Continuous Ambulatory PD and 39% Automated PD) patients: 37 with peritonitis and 12 without. Quantitative determination of LPS was performed by Enzyme-linked Immunosorbent Assay Kitin peritoneal and plasma samples. Results: Quantitative analysis of peritoneal and plasma LPS showed significantly higher levels in PD patients with peritonitis compared to patients without (p = 0.001). Furthermore, we divided patients with peritonitis in 2 groups on the basis of Gram staining (GP 27; GN 12). Peritoneal and plasma LPS levels showed significantly lower levels in PD patients with GP peritonitis than in patients with GN (p = 0.001). The median level of LPS showed no significant differences between patients without peritonitis and with GP peritonitis (p = 0.195). On the contrary, LPS levels showed significantly higher levels in PD patients with GN peritonitis compared to patients without peritonitis (p = 0.001). A significant positive correlation was observed between peritoneal white blood cells count (pWBC) and peritoneal LPS (Spearman’s rho = 0,412, p = 0.013). However, no statistically significant correlation was observed between plasma LPS and WBC count. Conclusion: We observed LPS presence in all PD patients. In particular, our results demonstrated that LPS is significantly elevated in PD patients with GN peritonitis. Furthermore, pWBC and LPS levels increased proportionally in PD patients with peritonitis. Peritoneal and plasma LPS levels could be a useful marker for diagnosis and management of GN peritonitis in PD patients.

Continuous Ambulatory Peritoneal Dialysis Peritonitis: Microbiology and Outcomes

AbstractContext: Continuous ambulatory peritoneal dialysis (CAPD) is now a preferred mode of the treatment in patients with end-stage renal disease, but peritonitis remains to be a shortcoming of CAPD. High-culture negativity, emerging drug resistance and peritoneal dialysis (PD)-related morbidity and mortality have been a challenge to tackle. Aims: The present study was taken up to compare the the various culture methods and to identify the spectrum of organisms causing CAPD peritonitis and their outcome. Settings and Design: A prospective, observational, cross-sectional study was conducted at a tertiary care teaching hospital in Hyderabad over a period of 1 year. Subjects and Methods: Dialysate fluid from 100 episodes of clinically suspected peritonitis in 75 patients was processed by conventional centrifuging, water lysis, direct inoculation and addition of centrifuged pellet into brain–heart infusion broth and by automated blood culture system. Identification and antibiotic susceptibility of organisms was done, and the outcome of PD-related peritonitis was analysed. Statistical Analysis Used: The categorical data and continuous data were analysed using the Chi-square test and Student’s t-test, respectively. P < 0.05 was considered statistically significant. Results: Of the 100 PD fluids, 87 were culture positive. Automated blood culture systems detected 87 episodes, whereas conventional centrifuge method detected only 53 episodes (P = 0.00001). Peritonitis due to Gram-negative organisms (62.3%) was higher than that of Gram-positive peritonitis (31.1%) and fungi (6.4%). Nineteen per cent episodes were constituted by relapse (9), refractory (4), recurrent (4) and repeat (2) peritonitis. Outcomes were analysed as recovery (77%), catheter removal (15%) and death (2.6%). Conclusions: Direct inoculation of peritoneal fluid into automated blood culture bottles increases the positivity rate and also aids in the early detection of CAPD peritonitis, helping reduce morbidity and mortality of PD patients.

SUN-079 INTERNATIONAL VARIATION IN PERITONEAL DIALYSIS-RELATED PERITONITIS RATES AND CLINICAL OUTCOMES: THE PERITONEAL DIALYSIS OUTCOMES AND PRACTICE PATTERNS STUDY (PDOPPS)

Peritoneal dialysis (PD)-associated peritonitis is a significant source of morbidity, dialysis-related treatment costs, and is the leading cause of permanent transfer to hemodialysis (HD). Here, we sought to understand if the risks of peritonitis and peritonitis-related outcomes differ by country and to identify patient and clinic/facility predictors of peritonitis. Peritonitis infection data from PDOPPS 1 (2015-2018) in Australia/New Zealand, Canada, Japan, Thailand, the UK, and the US were analyzed. Infections occurring within 21 days of a previous case, or infection by the same organism within 50 days of initial presentation were excluded per ISPD guidelines. We investigated several facility and patient factors associated with peritonitis using covariate-adjusted proportional-rates models. We estimated the proportion of events with cure, hospitalization, re-infection, catheter removal, permanent HD transfer, or death within 50 days of initial presentation using covariate-adjusted logistic regression models. Adjustment variables included age, sex, black race (US only), ESRD vintage, serum albumin, residual Kt/V, and 13 summary comorbidities. During 7455 patient-years of observation, we observed 1677 peritonitis events among 4618 patients across 143 facilities. Peritonitis rates (episodes per patient-year) varied from 0.19 in Japan to 0.27 in Australia/ New Zealand (TABLE). Gram-positive peritonitis rates ranged from 0.06 in Thailand to 0.11 in Australia/New Zealand and Canada. Gram-negative peritonitis rates ranged from 0.03 in Japan to 0.07 in Thailand. Culture negative peritonitis rates were highest in Thailand (0.07). The proportion of cases cured with antibiotics ranged from 55% in Thailand to 68% in Japan. The proportion of cases complicated by technique failure or death ranged from 16% in Japan to 27% in Thailand (TABLE). In adjusted analyses, lower peritonitis rates were observed in patients with higher serum albumin (HR=0.89 per 1 g/dl; 95% CI=0.80, 0.98), higher residual Kt/V (HR=0.79; 95% CI=0.65, 0.98); higher peritonitis rates were observed in patients with GI bleeding (HR=1.45; 95% CI=1.04, 2.02). Lower peritonitis rates were associated with facility use of antibiotic prophylaxis during catheter insertion (HR=0.68, 95% CI=0.52, 0.88) and use of exit-site gentamicin prophylaxis (HR=0.86, 95% CI=0.59, 1.25) or exit-site mupirocin prophylaxis (HR=0.83, 95% CI=0.61, 1.12) compared to none.View Large Image Figure ViewerDownload Hi-res image Download (PPT) In the largest international cohort of PD patients to date, we have demonstrated significant variations in peritonitis incidence and outcomes by country. In Thailand, a PD-first country with more limited resources, peritonitis incidence was comparable to other countries. However, a higher culture-negative peritonitis rate and significantly higher peritonitis-related adverse outcomes in Thailand compared to other countries (higher death, lower cure) suggest opportunities to improve peritonitis diagnosis and treatment. As a clinical practice, exit-site antimicrobial prophylaxis remains a mainstay of peritonitis prevention. Further investigation into the optimal exit site antimicrobial agent will be explored in PDOPPS along with other peritonitis prevention strategies.

Regional variation in the treatment and prevention of peritoneal dialysis-related infections in the Peritoneal Dialysis Outcomes and Practice Patterns Study.

Peritoneal dialysis (PD)-related infections lead to significant morbidity. The International Society for Peritoneal Dialysis (ISPD) guidelines for the prevention and treatment of PD-related infections are based on variable evidence. We describe practice patterns across facilities participating in the Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS). PDOPPS, a prospective cohort study, enrolled nationally representative samples of PD patients in Australia/New Zealand (ANZ), Canada, Thailand, Japan, the UK and the USA. Data on PD-related infection prevention and treatment practices across facilities were obtained from a survey of medical directors'. A total of 170 centers, caring for >11 000 patients, were included. The proportion of facilities reporting antibiotic administration at the time of PD catheter insertion was lowest in the USA (63%) and highest in Canada and the UK (100%). Exit-site antimicrobial prophylaxis was variably used across countries, with Japan (4%) and Thailand (28%) having the lowest proportions. Exit-site mupirocin was the predominant exit-site prophylactic strategy in ANZ (56%), Canada (50%) and the UK (47%), while exit-site aminoglycosides were more common in the USA (72%). Empiric Gram-positive peritonitis treatment with vancomycin was most common in the UK (88%) and USA (83%) compared with 10-45% elsewhere. Empiric Gram-negative peritonitis treatment with aminoglycoside therapy was highest in ANZ (72%) and the UK (77%) compared with 10-45% elsewhere. Variation in PD-related infection prevention and treatment strategies exist across countries with limited uptake of ISPD guideline recommendations. Further work will aim to understand the impact these differences have on the wide variation in infection risk between facilities and other clinically relevant PD outcomes.

The Relationship Between Body Mass Index and Organism-Specific Peritonitis.

Obesity is increasingly prevalent worldwide, and a greater number of patients initiate renal replacement therapy with a high body mass index (BMI). This study aimed to evaluate the association between BMI and organism-specific peritonitis. All adult patients who initiated peritoneal dialysis (PD) in Australia between January 2004 and December 2013 were included. Data were accessed through the Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry. The co-primary outcomes of this study were time to first organism-specific peritonitis episode, specifically gram-positive, gram-negative, culture-negative, and fungal. Secondary outcomes were individual rates of organism-specific peritonitis for the same 4 microbiological categories. There were 7,381 peritonitis episodes among the 8,343 incident PD patients evaluated. After multivariable adjustment, obese patients (BMI 30 - 34.9 kg/m2) had an increased risk of fungal peritonitis (adjusted hazard ratio [HR] 1.69, 95% confidence interval [CI] 1.18 - 2.42), very obese patients (BMI ≥ 35 kg/m2) had a significantly higher risk of gram-positive peritonitis (HR 1.15, 95% CI 1.02 - 1.30), while both obese and very obese patients experienced significantly higher risks of gram-negative peritonitis (HR 1.29, 95% CI 1.11 - 1.50 and HR 1.30, 95% CI 1.08 - 1.57, respectively) compared with patients with normal BMI (20 - 24.9 kg/m2). Obesity and severe obesity were independently associated with increased incidence rate ratios of all forms of organism-specific peritonitis with a non-significant trend for severe obesity and gram-negative peritonitis association. Among Australian patients, obesity and severe obesity are associated with significantly increased rates of gram-positive, gram-negative, fungal, and culture-negative peritonitis.

Isolation of bacterial DNA followed by sequencing and differing cytokine response in peritoneal dialysis effluent help in identifying bacteria in culture negative peritonitis.

The treatment of peritoneal dialysis related culture negative peritonitis is empirical which increases the cost of therapy and moreover antibiotic resistance. We aimed the study to isolate bacterial DNA from PD effluent and indentify bacteria causing peritonitis in culture negative situations. We have also studied the cytokine response with different bacteria causing peritonitis. We have isolated bacterial DNA from PD effluent of culture negative and culture positive peritonitis patients. Bacterial DNA was subjected to polymerase chain reaction using universal bacteria specific primers and subsequently to Gram type specific primers for the differentiation of the etiologic agents into Gram-positive and Gram-negative. The amplified products were sequenced and subjected to blast search to identify agent at genus/ species level. Of the 30 molecular method positive samples, 16 (53.33%) samples were positive for Gram-negative bacteria and 4 (13.33%) for Gram-positive, while the remaining10 (33.33%) were positive for both Gram-positive and Gram-negative bacteria. We have found organisms that usually do not grow on normal culture methods. TNF-α was significantly associated with Gram-positive peritonitis and regulatory cytokine IL-10 with Gram-negative peritonitis. The molecular techniques are helpful in detecting and identifying organisms from culture negative PD effluent.

Outcomes of Corynebacterium Peritonitis: A Multicenter Registry Analysis.

Corynebacterium is a rare cause of peritonitis that is increasingly being recognized in peritoneal dialysis (PD) patients. The aims of this study were to compare Corynebacterium peritonitis outcomes with those of peritonitis caused by other organisms and to examine the effects of type and duration of antibiotic therapy on outcomes of Corynebacterium peritonitis. Using Australia and New Zealand Dialysis and Transplant Registry (ANZDATA) data, we included all PD patients who developed peritonitis in Australia between 2004 and 2014. The primary outcome was peritonitis cure by antibiotic therapy, defined as resolution of a peritonitis episode with antibiotics alone and without being complicated by recurrence, relapse, catheter removal, hemodialysis transfer, or death. Peritonitis outcomes were analyzed using multivariable logistic regression. A total of 11,122 episodes of peritonitis in 5,367 patients were included. Of these, 162 episodes (1.5%) were due to Corynebacterium. Compared with Corynebacterium peritonitis, the odds of cure were lower in peritonitis due to Staphylococcus aureus (odds ratio [OR] 0.66, 95% confidence interval [CI] 0.45 - 0.97), Pseudomonas (OR 0.22, 95% CI 0.14 - 0.33), other gram-negative organisms (OR 0.52, 95% CI 0.35 - 0.75), fungi (OR 0.02, 95% CI 0.01 - 0.03), polymicrobial organisms (OR 0.32, 95% CI 0.22 - 0.47), and other organisms (OR 0.66, 95% CI 0.44 - 0.99) but similar for culture-negative and other gram-positive peritonitis. Similar results were observed for hemodialysis transfer and death. The outcomes of Corynebacterium peritonitis were not associated with the type of initial antibiotic selected (vancomycin vs cefazolin) or the duration of antibiotic therapy (≤ 14 days vs > 14 days). Outcomes for Corynebacterium peritonitis are generally favorable compared with other forms of peritonitis. Cure rates did not appear to differ if peritonitis was treated initially with vancomycin or cefazolin or if treatment duration was prolonged beyond 14 days.

Causative organisms and outcomes of peritoneal dialysis-related peritonitis in Sarawak General Hospital, Kuching, Malaysia: a 3-year analysis

BackgroundPeritoneal dialysis peritonitis remains a significant cause of morbidity for peritoneal dialysis patients and the main reason for conversion from peritoneal dialysis to hemodialysis. As the characteristics of patients and microbial susceptibility vary from center to center, the aim of this study is to evaluate the microbiology and the clinical outcomes among continuous ambulatory peritoneal dialysis patients in Kuching, Malaysia.MethodsThis is a retrospective record review of 82 continuous ambulatory peritoneal dialysis patients who developed peritonitis during 2013 to 2015. Data examined included patients’ demographic data, causative organisms, and outcomes.ResultsA total of 124 episodes of peritonitis were recorded, and the overall peritonitis rate was 0.40 episodes per patient-year. There was an increasing incidence in continuous ambulatory peritoneal dialysis peritonitis over the 3-year study period (0.35 to 0.47 episodes per patient-year). The gram-negative peritonitis rate increased over the period until towards the end of the study period, when gram-positive and gram-negative organisms accounted for almost equal proportions of peritonitis. Streptococcus sp. was the most common organism among the gram-positive peritonitis while Pseudomonas sp. was the most common organism in gram-negative peritonitis. The culture-negative peritonitis rate was 25.8%. The peritoneal dialysis catheter was removed in 32 episodes (26.6%). The catheter loss rate was significantly higher in gram-negative peritonitis, as compared to gram-positive peritonitis (38.9 vs 16.7%, p = 0.027).ConclusionsThe increasing trend of peritonitis and high rates of culture negativity and peritoneal dialysis catheter removal are areas that need further evaluation and improvement in the future. Study on risk factors of continuous ambulatory peritoneal dialysis peritonitis, detailed microbiology, and antimicrobial treatment and response are warranted to further improve the outcomes of continuous ambulatory peritoneal dialysis patients.

Age‐Related Differences of Organism‐Specific Peritonitis Rates: A Single‐Center Experience

Peritonitis remains an important cause of morbidity and mortality in peritoneal dialysis (PD) patients, but its incidence and the distribution of causative organisms vary widely between institutions and age groups. This study was performed to investigate the recent status and risk factors of PD-related peritonitis and to clarify differences between age groups. We retrospectively reviewed the medical records of 119 PD patients treated at our department between January 2002 and January 2013. We calculated both overall and organism-specific peritonitis rates and also analyzed risk factors. Sixty-three episodes of peritonitis occurred during 261.5 patient-years for an incident rate of 0.24 episodes/patient-year. Multivariate analysis showed that older age (≥65 years) and hypoalbuminemia (<3.0 g/dL) were associated with an increased risk of peritonitis (P = 0.035 and P = 0.029, respectively). In elderly patients (≥65 years old), the rate of peritonitis due to Gram-positive and Gram-negative bacteria was 0.17 and 0.08 episodes/patient-year, respectively, and Gram-positive peritonitis was markedly more frequent than in younger patients (<65 years old). In particular, there was a high frequency of Staphylococcus aureus peritonitis in elderly patients (0.09 episodes/patient-year) and it had a poor outcome. At our department, the risk of peritonitis was increased in older patients and patients with hypoalbuminemia. The distribution of causative organisms was markedly different between age groups and analysis of organism-specific peritonitis rates helped to identify current problems with our PD program.

Risk Factors for and Outcomes of Catheter-Associated Peritonitis in Children: The SCOPE Collaborative.

The Standardizing Care to Improve Outcomes in Pediatric ESRD Collaborative is a quality improvement initiative that aims to reduce peritoneal dialysis-associated infections in pediatric patients on chronic peritoneal dialysis. Our objectives were to determine whether provider compliance with peritoneal dialysis catheter care bundles was associated with lower risk for infection at the individual patient level and describe the epidemiology, risk factors, and outcomes for peritonitis in the Standardizing Care to Improve Outcomes in Pediatric ESRD Collaborative. We collected peritoneal dialysis characteristics, causative organisms, compliance with care bundles, and outcomes in children with peritonitis between October of 2011 and September of 2014. Chi-squared tests, t tests, and generalized linear mixed models were used to assess risk factors for peritonitis. Of 734 children enrolled (54% boys; median age =9 years old; interquartile range, 1-15) from 29 centers, 391 peritonitis episodes occurred among 245 individuals over 10,130 catheter-months. The aggregate annualized peritonitis rate was 0.46 episodes per patient-year. Rates were highest among children ≤2 years old (0.62 episodes per patient-year). Gram-positive peritonitis predominated (37.8%) followed by culture-negative (24.7%), gram-negative (19.5%), and polymicrobial (10.3%) infections; fungal only peritonitis accounted for 7.7% of episodes. Compliance with the follow-up bundle was associated with a lower rate of peritonitis (rate ratio, 0.49; 95% confidence interval, 0.30 to 0.80) in the multivariable model. Upward orientation of the catheter exit site (rate ratio, 4.2; 95% confidence interval, 1.49 to 11.89) and touch contamination (rate ratio, 2.22; 95% confidence interval, 1.44 to 3.34) were also associated with a higher risk of peritonitis. Infection outcomes included resolution with antimicrobial treatment alone in 76.6%, permanent catheter removal in 12.2%, and catheter removal with return to peritoneal dialysis in 6% of episodes. Lower compliance with standardized practices for follow-up peritoneal dialysis catheter care in the Standardizing Care to Improve Outcomes in Pediatric ESRD Collaborative was associated with higher risk of peritonitis. Quality improvement and prevention strategies have the potential to reduce peritoneal dialysis-associated peritonitis.