Microbiology and outcomes of peritonitis in North America

Effect of platelet indices on mortality and comorbidity in peritoneal dialysis: a cohort study

BACKGROUND

There were limited data investigating platelet indices in predicting peritoneal dialysis (PD) outcomes on comorbidities. The aim of this study was to evaluate the association between platelet indices and new-onset comorbidity and all-cause mortality in PD patients.

METHODS

A single-center, retrospective observational cohort study was conducted in incident PD patients from 28 December 2011 to 24 January 2018, and followed up until 31 December 2022. Time to the first new-onset cardiovascular disease (CVD) and time to the first new-onset infection event after PD were identified as the primary outcomes. All-cause mortality was identified as the secondary endpoint. The correlation between platelet indices and comorbidities and all-cause mortality were assessed by Cox model. Data of liver disease status was not collected and analyzed. Survival curves were performed by Kaplan-Meier method with log-rank tests.

RESULTS

A total of 250 incident PD patients with a median follow-up of 6.79 (inter-quarter range 4.05, 8.89) years was included. A total of 81 and 139 patients experienced the first new-onset CVD and infection event respectively during the follow-up period. High mean platelet volume (MPV) was independently associated with high risk of time to the first new-onset CVD (HR 1.895, 95% CI 1.174-3.058, p = 0.009) and all-cause mortality (HR 1.710, 95% CI 1.155-2.531, p = 0.007). Patients with low mean platelet volume to platelet count ratio (MPV/PC) were prone to occur the new-onset infection events (log rank 5.693, p = 0.017). Low MPV/PC (HR 0.652, 95% CI 0.459-0.924, p = 0.016) was significantly associated with the time to the first new-onset infection event on PD.

CONCLUSIONS

Platelet indices were associated with the new-onset CVD, infectious comorbidities and all-cause mortality on PD. Low MPV/PC was associated with time to the first new-onset infection event in PD patients. Moreover, high MPV was associated with new-onset CVD and all-cause mortality in the incident PD patients.

Effectiveness of a Customized Peritoneal Dialysis Training Program in Reducing Infection and Dropout Rates: Insights From a Singapore Hospital

Introduction Peritoneal dialysis (PD) is an essential home-based treatment for end-stage kidney disease, known for enhancing patients' quality of life and being more cost-effective compared to hemodialysis. However, in Singapore, PD education lacks of standardization, with each unit adopting varied methods based on their own experiences and resources. To address this, our hospital developed a tailored four-day PD training program guided by the International Society for Peritoneal Dialysis guidelines, adapted to meet local needs and resource availability. Methodology This study employed a retrospective cohort design, including all incident adult patients aged 18 years and above who initiated PD at our hospital from September 2018 to July 2023. Data on PD dropout rates and PD-related infection rates, such as PD peritonitis and exit site infection rates, were obtained from electronic medical records. Results This study comprised 99 patients who began PD and completed their PD training program at our hospital between September 2018 and July 2023. Our tailored PD training program successfully reduced dropout rates and maintained infection rates within the International Society for Peritoneal Dialysis guidelines. Specifically, exit site infection rates fluctuated between 0.18 and 0.29 episodes per year, PD peritonitis rates ranged from 0.2 to 0.26 episodes per patient-year, and dropout rates significantly improved from 40% in 2019 to 7% in 2023 (OR = 0.45, 95% CI = 0.49 to 0.84, p = 0.010). Conclusions The tailored PD training program at our hospital effectively reduced PD-related infections and dropout rates among end-stage kidney disease patients. These findings suggest that structured, locally adapted training programs can substantially improve patient outcomes in PD.

Refractory Peritonitis Related to Peritoneal Dialysis Caused by Enterococcus gallinarum

A 65-year-old woman with a history of peritoneal dialysis undergoing hemodialysis at our hospital presented with a fever after experiencing gastroenteritis symptoms. She had an implanted peritoneal dialysis catheter for draining chylous ascites. After commencing empirical treatment with meropenem, peritoneal effluent samples revealed an increased white blood cell count, and peritonitis was diagnosed. Enterococcus gallinarum was detected in blood and effluent cultures. Meropenem was changed to vancomycin based on susceptibility testing but subsequently restarted and thereafter changed to ampicillin following exacerbation of peritonitis. Finally, catheter removal led to complete recovery. E. gallinarum is vancomycin-resistant and a rare cause of peritonitis.

Efficacy of sucrose and povidone-iodine mixtures in peritoneal dialysis catheter exit-site care

BACKGROUND

Exit-site infection (ESI) is a common recurring complication in patients undergoing peritoneal dialysis (PD). Sucrose and povidone-iodine (SPI) mixtures, antimicrobial ointments that promote wound healing, have been used for the treatment of ulcers and burns, but their efficacy in exit-site care is still unclear.

METHODS

This single-center retrospective observational study included patients who underwent PD between May 2010 and June 2022 and presented with episodes of ESI. Patients were divided into SPI and non-SPI groups and followed up from initial ESI onset until PD cessation, death, transfer to another facility, or June 2023.

RESULTS

Among the 82 patients (mean age 62, [54-72] years), 23 were treated with SPI. The median follow-up duration was 39 months (range, 14-64), with an overall ESI incidence of 0.70 episodes per patient-year. Additionally, 43.1% of second and 25.6% of third ESI were caused by the same pathogen as the first. The log-rank test demonstrated significantly better second and third ESI-free survival in the SPI group than that in the non-SPI group (p < 0.01 and p < 0.01, respectively). In a Cox regression analysis, adjusting for potential confounders, SPI use was a significant predictor of decreased second and third ESI episodes (hazard ratio [HR], 0.22; 95% confidence interval [CI], 0.10-0.52 and HR, 0.22; 95%CI, 0.07-0.73, respectively).

CONCLUSIONS

Our results showed that the use of SPI may be a promising option for preventing the incidence of ESI in patients with PD.

TRIAL REGISTRATION

This study was approved by the Keio University School of Medicine Ethics Committee (approval number 20231078) on August 28, 2023. Retrospectively registered.

Staphylococcus aureus small colony variants: A potentially underestimated microbiological challenge in peritoneal dialysis

INTRODUCTION

Peritonitis remains the major infectious complication in the setting of peritoneal dialysis (PD). Despite known only moderate pathogenicity, the most frequently detected pathogens in PD-related peritonitis are surprisingly coagulase-negative staphylococci. However, this could be explained, at least in part, by Staphylococcus aureus small colony variants (SCVs) induced by PD fluids (PDFs) and misidentified by routinely used microbiological methods.

MATERIAL AND METHODS

Bacteria were exposed to commonly used PDFs in various regimens designed to simulate daily use as closely as possible. Wild-type isolates and SCVs were subsequently used to determine minimum inhibitory concentrations (MICs), in vitro biofilm formation capacities, and auxotrophies. Underlying genetic alterations were investigated using whole-genome sequencing, and various microbial identification methods were tested to determine their performance for wild-types and SCVs.

RESULTS

Stable SCVs could be isolated most successfully after exposure to glucose-containing PDFs alone. The reading of MICs was significantly affected by the reduced growth of SCVs, resulting in lower MIC values in 44% of all tests. Nonsynonymous mutations were found in all but one SCV, while only two isolates showed typical auxotrophic responses. While MALDI-TOF, PCR and Pastorex Staph-Plus correctly identified all S. aureus SCVs, API-Staph and VITEK-2 yielded identification rates of only 40% and 10%, respectively.

CONCLUSIONS

Overall, the present study has shown that commercially available PDFs induce S. aureus SCVs in vitro, which are difficult to identify and test for antimicrobial susceptibility and can potentially lead to recurrent or persistent infections. Thus, they represent a potentially underappreciated challenge not only for microbiologists, but also for clinicians.

Staphylococcus lugdunensis Peritoneal Dialysis-Related Peritonitis: A Matched Comparative Analysis

Rationale & Objective

Staphylococcus lugdunensis (S lugdunensis) is a coagulase-negative staphylococcus species that has been increasingly recognized to cause serious infections with virulence resembling Staphylococcus aureus (S aureus). No studies have evaluated the characteristics and outcomes of patients with S lugdunensis peritoneal dialysis-related peritonitis compared with those with S aureus peritonitis. We aim to evaluate the clinical course of peritonitis as caused by these organisms.

Study Design

A retrospective matched comparative analysis involving a single tertiary center from July 2000 to July 2020.

Setting & Participants

Forty-eight episodes of S aureus peritonitis were matched to 19 cases of S lugdunensis peritonitis.

Analytical Approach

The cases were individually matched for year of peritonitis, sex, age (±10 years), and Charlson Comorbidity Index (±3). A comparative analysis was performed between the 2 organisms. The outcome includes responses at day 5 of peritonitis and the rate of complete response.

Results

There is a higher predilection of diabetes in those with S aureus peritonitis than in those with S lugdunensis (64.6% vs 31.6%; P = 0.03). Patients with S aureus peritonitis also have a much higher total cell count at presentation (4,463.9 ± 5,479.5 vs 1,807.9 ± 3,322.7; P = 0.05); a higher prevalence of poor response at day 5 (50.0% vs 15.8%; P = 0.03); a lower rate of complete response (64.6% vs 94.7%; P = 0.01) and are more prone to relapse with the same organism (29.2% vs 0%, respectively; P = 0.01) as compared to those with S lugdunensis.

Limitations

The result of this small retrospective study involving a single center may not be generalizable to other centers. There is also no data for comparative analysis on other coagulase-negative staphylococci such as Staphylococcus epidermidis, which belongs to the same family as S lugdunensis.

Conclusions

Although S aureus peritonitis is more virulent with significant morbidity, S lugdunensis can cause similarly serious peritonitis. This largest case series of S lugdunensis peritonitis enabled better characterization of clinical features and outcomes of patients with S lugdunensis peritonitis.

A population-based study on the incidence and aetiology of infectious complications in peritoneal dialysis in South Sweden

BACKGROUND

Peritonitis is a major cause of morbidity in peritoneal dialysis (PD) and an independent risk factor for elevated all-cause mortality. The aims of this study were to report the incidence, trend, aetiology, and antimicrobial susceptibility of PD-associated peritonitis and catheter-related infections in South Sweden between 2011-2020.

METHODS

This population-based observational cohort study included all patients with PD between the years 2011-2020 in the county of Skåne. Data was accessed through the Swedish Renal Registry and the Department of Clinical Microbiology in Lund. Definitions issued by the International Society for Peritoneal Dialysis were implemented to assess PD-associated infections.

RESULTS

Medical records of 675 paediatric and adult PD patients were eligible for inclusion. Of those, 208 (31%) were female and the median age was 67 years (range 0-91). The overall rate of PD-peritonitis was 0.38 episodes per year at risk. Out of 484 episodes of peritonitis, 61% (n = 295) were caused by Gram-positive bacteria. There were 289 occurrences of exit site infections, of which most (n = 152, 53%) were Gram-positive. Tunnel infections occurred in 16 episodes and were caused by S. aureus or P. aeruginosa. Among all isolates, 37 were of MRSE, four of ESBL-producing E. coli, and one of MRSA.

CONCLUSION

The crude rate of PD-peritonitis was stable during the study period. Gram-positive bacteria dominated the microbial aetiology, and antibiotic resistance was limited. It is important to monitor the aetiology, incidence, and resistance rates in PD-associated infections, to base empirical antibiotic regimens and facilitate prevention.

Calprotectin blockade inhibits long-term vascular pathology following peritoneal dialysis-associated bacterial infection

Bacterial infections and the concurrent inflammation have been associated with increased long-term cardiovascular (CV) risk. In patients receiving peritoneal dialysis (PD), bacterial peritonitis is a common occurrence, and each episode further increases late CV mortality risk. However, the underlying mechanism(s) remains to be elucidated before safe and efficient anti-inflammatory interventions can be developed. Damage-Associated Molecular Patterns (DAMPs) have been shown to contribute to the acute inflammatory response to infections, but a potential role for DAMPs in mediating long-term vascular inflammation and CV risk following infection resolution in PD, has not been investigated. We found that bacterial peritonitis in mice that resolved within 24h led to CV disease-promoting systemic and vascular immune-mediated inflammatory responses that were maintained up to 28 days. These included higher blood proportions of inflammatory leukocytes displaying increased adhesion molecule expression, higher plasma cytokines levels, and increased aortic inflammatory and atherosclerosis-associated gene expression. These effects were also observed in infected nephropathic mice and amplified in mice routinely exposed to PD fluids. A peritonitis episode resulted in elevated plasma levels of the DAMP Calprotectin, both in PD patients and mice, here the increase was maintained up to 28 days. In vitro, the ability of culture supernatants from infected cells to promote key inflammatory and atherosclerosis-associated cellular responses, such as monocyte chemotaxis, and foam cell formation, was Calprotectin-dependent. In vivo, Calprotectin blockade robustly inhibited the short and long-term peripheral and vascular consequences of peritonitis, thereby demonstrating that targeting of the DAMP Calprotectin is a promising therapeutic strategy to reduce the long-lasting vascular inflammatory aftermath of an infection, notably PD-associated peritonitis, ultimately lowering CV risk.

Comparison of clinical outcomes between culture-negative and positive peritonitis in patients undergoing maintenance peritoneal dialysis: a prospective cohort study

BACKGROUND

Culture-negative peritonitis is a serious complication in patients undergoing maintenance peritoneal dialysis (PD) and occurs in up to 40% of all peritonitis episodes. Despite its high incidence, data regarding treatment response and prognosis remain poorly defined. This study compared the clinical outcomes of patients with culture-negative and positive peritonitis.

METHOD

This prospective cohort study was conducted between 2021 and 2022. Patients treated with maintenance PD who developed PD-associated peritonitis were included and received standard treatment. The primary endpoint was the primary response (resolution of peritonitis 10 days after the initiation of treatment).

RESULTS

Of the 81 patients who developed PD-associated peritonitis during the study, 35 and 46 had culture-negative and culture-positive peritonitis, respectively. Overall, 52 (64.2%) patients achieved the primary response: 24 (68.6%) in the culture-negative group and 28 (60.9%) in the culture-positive group (p = 0.630). There were no significant differences between the two groups in the incidence of complete cure (complete resolution of peritonitis without the need for Tenckhoff catheter removal or salvage antibiotic therapy or peritonitis within 120 days after treatment) (culture-negative vs. culture-positive group, 57.1% vs. 45.7%), refractory peritonitis (28.6% vs. 41.3%), relapse peritonitis (8.6% vs. 2.2%), repeat peritonitis (11.4% vs. 10.9%), salvage antibiotics (40.0% vs. 50.0%), permanent hemodialysis transfer (11.4% vs. 10.9%), Tenckhoff catheter removal (25.7% vs. 41.3%), or mortality (2.9% vs. 2.2%) (all p > 0.05).

CONCLUSION

This study offers valuable insights into the clinical outcomes of culture-negative peritonitis versus culture-positive peritonitis. However, caution must be exercised in interpreting these findings due to the limitations of the small sample size.

CLINICAL TRIAL REGISTRATION

The study was retrospectively registered in the Thai Clinical Trials Registry (TCTR20221130006).

Characteristics and outcomes of hospital-acquired and community-acquired peritonitis in patients on peritoneal dialysis: a retrospective cohort study

BACKGROUND

Peritonitis remains a significant complication of peritoneal dialysis. However, there is limited information on the clinical characteristics and outcomes of hospital-acquired peritonitis compared to community-acquired peritonitis in patients undergoing peritoneal dialysis. Furthermore, the microbiology and outcomes of community-acquired peritonitis may vary from hospital-acquired peritonitis. Therefore, the aim was to gather and analyse data to address this gap.

METHODS

Retrospective review of the medical records of all adult patients on peritoneal dialysis within the peritoneal dialysis units in four university teaching hospitals in Sydney, Australia, who developed peritonitis between January 2010 and November 2020. We compared the clinical characteristics, microbiology and outcomes of community-acquired peritonitis and hospital-acquired peritonitis. Community acquired peritonitis was defined as the development of peritonitis in the outpatient setting. Hospital-acquired peritonitis was defined as: (1) developed peritonitis anytime during hospitalisation for any medical condition other than peritonitis, (2) diagnosed with peritonitis within 7 days of hospital discharge and developed symptoms of peritonitis within 3 days of the hospital discharge.

RESULTS

Overall, 904 episodes of peritoneal dialysis-associated peritonitis were identified in 472 patients, of which 84 (9.3%) episodes were hospital-acquired. Patients with hospital-acquired peritonitis had lower mean serum albumin levels compared to those with community-acquired peritonitis(22.95 g/L vs. 25.76 g/L, p = 0.002). At the time of diagnosis, lower median peritoneal effluent leucocyte and polymorph counts were observed with hospital-acquired peritonitis compared to community-acquired peritonitis (1236.00/mm3 vs. 3183.50/mm3, p < 0.01 and 1037.00/mm3 vs. 2800.00/mm3, p < 0.01, respectively). Higher proportions of peritonitis due to Pseudomonas spp. (9.5% vs. 3.7%, p = 0.020) and vancomycin-resistant Enterococcus (2.4% vs. 0.0%, p = 0.009), lower rates of complete cure (39.3% vs. 61.7%, p < 0.001), higher rates of refractory peritonitis (39.3% vs. 16.4%, p < 0.001) and higher all-cause mortality within 30 days of peritonitis diagnosis (28.6% vs. 3.3%, p < 0.001) were observed in the hospital-acquired peritonitis group compared to the community-acquired peritonitis group, respectively.

CONCLUSIONS

Despite having lower peritoneal dialysis effluent leucocyte counts at the time of diagnosis, patients with hospital-acquired peritonitis had poorer outcomes, including lower rates of complete cure, higher rates of refractory peritonitis and higher rates of all-cause mortality within 30 days of diagnosis, compared to those with community-acquired peritonitis.

Development and validation of a nomogram for predicting gram-negative bacterial infections in patients with peritoneal dialysis-associated peritonitis

Background

This study aimed to develop a nomogram for predicting gram-negative bacterial (GNB) infections in patients with peritoneal dialysis-associated peritonitis (PDAP) to identify patients at high risk for GNB infections.

Methods

In this investigation, hospitalization information was gathered retrospectively for patients with PDAP from January 2016 to December 2021. The concatenation of potential biomarkers obtained by univariate logistic regression, LASSO analysis, and RF algorithms into multivariate logistic regression was used to identify confounding factors related to GNB infections, which were then integrated into the nomogram. The concordance index (C-Index) was utilized to assess the precision of the model's predictions. The area under the curve (AUC) and decision curve analysis (DCA) was used to assess the predictive performance and clinical utility of the nomogram.

Results

The final study population included 217 patients with PDAP, and 37 (17.1%) patients had gram-negative bacteria due to dialysate effluent culture. After multivariate logistic regression, age, procalcitonin, and hemoglobin were predictive factors of GNB infections. The C-index and bootstrap-corrected index of the nomogram for estimating GNB infections in patients were 0.821 and 0.814, respectively. The calibration plots showed good agreement between the predictions of the nomogram and the actual observation of GNB infections. The AUC of the receiver operating characteristic curve was 0.821, 95% CI: 0.747-0.896, which indicates that the model has good predictive accuracy. In addition, the DCA curve showed that the nomogram had a high clinical value in the range of 1%-94%, which further demonstrated that the nomogram could accurately predict GNB infection in patients with PDAP.

Conclusions

We have created a new nomogram for predicting GNB infections in patients with PDAP. The nomogram model may improve the identification of GNB infections in patients with PDAP and contribute to timely intervention to improve patient prognosis.

Microbial Profile, Peritoneal Fluid White Blood Cell Count, and Outcome of Peritoneal Dialysis-Related Peritonitis at Indonesian Tertiary Hospital

Introduction

Peritonitis caused by peritoneal dialysis (PD) remains a common complication of continuous ambulatory PD (CAPD). The purpose of this study is to determine the microbial profile in CAPD-related peritonitis, the optimal cutoff of white blood cell (WBC) count, and the percentage of polymorphonuclear (PMN) in CAPD fluid in the prediction of CAPD-related peritonitis, together with the outcome of CAPD-related peritonitis at an Indonesian tertiary hospital. This is a retrospective cohort study of CAPD-related peritonitis patients at Indonesian tertiary hospitals from November 2020 to October 2022.

Methods

Patients with suspected CAPD-related peritonitis who were tested for CAPD fluid culture and WBC count in CAPD fluid were eligible for this study. Patient's diagnosis and outcome obtained from medical records. Differences in clinical outcomes by category of microorganisms were analyzed with Fisher exact test. The Mann-Whitney test and receiver operating characteristic curve were used to determine optimal WBC and PMN cutoff.

Results

This study included 58 patients and 102 episodes of CAPD-related peritonitis. CAPD-related peritonitis was caused by 29.4% Gram-negative bacteria, 21.5% Gram-positive bacteria, 7.8% fungi, and 6.9% polymicrobial bacteria. CAPD fluid WBC count >79 cells/μL and PMN percentage >50% had a sensitivity of 76.4% and a specificity of 92.9% in predicting CAPD-related peritonitis. There was a significant difference in outcome between Gram-negative and Gram-positive bacterial peritonitis.

Conclusions

It is critical to understand the microbial profile in CAPD-related peritonitis. Lower WBC count cutoff points in CAPD fluids may improve sensitivity in predicting CAPD-related peritonitis.

Potential clinical value of catheters impregnated with antimicrobials for the prevention of infections associated with peritoneal dialysis

INTRODUCTION

Peritoneal dialysis (PD) is a widely used dialysis modality, which offers the advantage of being a home therapy but is associated with a risk of potentially serious infections, including exit site infection, catheter tunnel infection, and peritonitis that may result in morbidity, technique failure, and increased mortality. Catheters impregnated with antimicrobials hold promise as a novel technique to reduce PD associated infections.

AREAS COVERED

We describe PD modalities, catheters, technique, complications, and the microbiology of associated infections, as well as standard measures to reduce the risk of infection. A novel technique for the impregnation of silicone devices with antimicrobial agents has been used to produce antimicrobial impregnated ventricular shunt catheters with proven clinical efficacy that have now been adopted as the standard of care to reduce neurosurgical infections. Using the same technology, we have developed PD and urinary catheters impregnated with sparfloxacin, triclosan, and rifampicin. Safety and tolerability have been demonstrated in urinary catheters, and a similar study is planned in PD catheters.

EXPERT OPINION

Catheters impregnated with antimicrobials offer a simple technique to reduce PD associated infections and thereby enable more people to enjoy the advantages of PD. Clinical trials are needed to establish efficacy.

High C-reactive protein and number of previous episodes at diagnosis increase the risk of catheter removal in peritoneal dialysis-related peritonitis in children

BACKGROUND

A minority of patients with peritonitis require removal of peritoneal dialysis (PD) catheters. We examined risk factors at diagnosis that could predict the removal of PD catheter before obtaining the results of treatment success in children with peritonitis.

METHODS

We analyzed 156 peritonitis episodes in 57 pediatric PD patients.

RESULTS

The peritonitis rate was 0.68 peritonitis episode per patient year. Catheter removal was required in 22 of 156. C-reactive protein (CRP) ≥ ×10 of upper limit at diagnosis and increased previous episode number were found to be associated with catheter removal (OR [95% CI] 6.4 [2.3-18.1], p = 0.001 and 3.8 [1.4-10.6], p = 0.009).

CONCLUSION

These findings supported that CRP could be an early marker in predicting catheter removal even before obtaining the results of treatment success. Furthermore, it should be kept in mind that the risk of catheter removal is high in patients with high number of previous episodes especially of three or more.

Association of longitudinal high-sensitive C-reactive protein levels with changing membrane characteristics in peritoneal dialysis

BACKGROUND

Increasing peritoneal permeability with ultrafiltration and solute removal inadequacy is a challenging issue in peritoneal dialysis (PD). Decreasing permeability is less frequent but also results in diminished solute clearance. We evaluated the association between longitudinal high-sensitive C-reactive protein (hs-CRP) values and the change in transport characteristics of the peritoneal membrane in PD patients.

METHODS

This is a retrospective, single-center study of incident PD patients. An increase or decrease in peritoneal transport status is defined as two or more categories of a rise or decline in the peritoneal equilibration test (PET) from their baseline during follow-up. The 4-h dialysate/plasma creatinine ratio was used to classify transport characteristics. Hs-CRP values were obtained from the routine annual examinations of the patients.

RESULTS

Baseline demographics, residual kidney function, frequency of high glucose-containing dialysate, and icodextrin use were similar between the groups. Total episodes of peritonitis within the first 5 years of follow-up were higher in stable transporters than in increased and decreased transporters (p = 0.009). Stable transporters' mean hs-CRP values did not change within 5 years (Wilks' λ = 0.873, F (2.317, 180.740) = 2.210, p = 0.10). Increased and decreased transporters' hs-CRP values significantly raised over the years (Wilks' λ = 0.422, F (1.979, 77.163) = 3.405, p = 0.04 and Wilks' λ = 0.558, F (3.673, 66.107) = 4.396, p = 0.001, respectively).

CONCLUSIONS

Our study shows that the peritoneal membrane may change into different characteristics in many patients over time, despite very low peritonitis frequencies and similar baseline characteristics that may be significantly affected by systemic inflammation.

Periton Diyalizi İle ilişkili Peritonitlerin İrdelenmesi

Objective: In this study, it was aimed to determine the causative microorganisms isolated in peritonitis attacks in peritoneal dialysis (PD) patients in our hospital and methicilline resistance rate in Staphlococci. Material and methods: 194 patients in the peritoneal dialysis unit of XXXXl Training and Research Hospital, Nephrology Clinic, between January 2009 and 2020, were evaluated retrospectively in terms of peritonitis development, causative microorganisms and methicillin resistance in Stapylococci, which is the most common causative agent. Results: Peritonitis attack developed in 149 out of a total of 194 patients. The causative agent has been isolated in 91 (61%) of the patients who developed peritonitis. When we look at the order of frequency among all microorganisms isolated, methicillin-susceptible Staphylococci (MHS) 59 (44.02%), methicillin-resistant Staphylococci (MRS) 28 (20.89%), Escherichia coli 12 (8.95%), Streptococcus spp 12 (8.95%), Enterobacter spp 7 (5.22%), Pseudomonas spp 4 (2.98%), diphtheroid bacilli 4 (2.98%), Klebsiella spp 2 (1.49%), Acinetobacter spp 1 (0.07%), a total of 129 bacteria, including five fungi were detected. Methicillin resistance rate was 32.18% among Staphylococci, which was found to be the most common causative agent. Conclusion: There is a need for studies with large patient groups to show the agents of peritonitis and the change in the resistance profile these microorganisms. Key words: Peritoneal Dialysis, Peritonitis, Methicillin Resistance

Epidemiology of peritoneal dialysis outcomes

Peritoneal dialysis (PD) is an important home-based treatment for kidney failure and accounts for 11% of all dialysis and 9% of all kidney replacement therapy globally. Although PD is available in 81% of countries, this provision ranges from 96% in high-income countries to 32% in low-income countries. Compared with haemodialysis, PD has numerous potential advantages, including a simpler technique, greater feasibility of use in remote communities, generally lower cost, lesser need for trained staff, fewer management challenges during natural disasters, possibly better survival in the first few years, greater ability to travel, fewer dietary restrictions, better preservation of residual kidney function, greater treatment satisfaction, better quality of life, better outcomes following subsequent kidney transplantation, delayed need for vascular access (especially in small children), reduced need for erythropoiesis-stimulating agents, and lower risk of blood-borne virus infections and of SARS-CoV-2 infection. PD outcomes have been improving over time but with great variability, driven by individual and system-level inequities and by centre effects; this variation is exacerbated by a lack of standardized outcome definitions. Potential strategies for outcome improvement include enhanced standardization, monitoring and reporting of PD outcomes, and the implementation of continuous quality improvement programmes and of PD-specific interventions, such as incremental PD, the use of biocompatible PD solutions and remote PD monitoring.

The use of peritoneal dialysis (PD) can be advantageous compared with haemodialysis treatment, although several barriers limit its broad implementation. This review examines the epidemiology of peritoneal dialysis (PD) outcomes, including clinical, patient-reported and surrogate PD outcomes.

Peritoneal dialysis (PD) has distinct advantages compared with haemodialysis, including the convenience of home treatment, improved quality of life, technical simplicity, lesser need for trained staff, greater cost-effectiveness in most countries, improved equity of access to dialysis in resource-limited settings, and improved survival, particularly in the first few years of initiating therapy.

Important barriers can hamper PD utilization in low-income settings, including the high costs of PD fluids (owing to the inability to manufacture them locally and the exorbitant costs of their import), limited workforce availability and a practice culture that limits optimal PD use, often leading to suboptimal outcomes.

PD outcomes are highly variable around the world owing in part to the use of variable outcome definitions, a heterogeneous practice culture, the lack of standardized monitoring and reporting of quality indicators, and kidney failure care gaps (including health care workforce shortages, inadequate health care financing, suboptimal governance and a lack of good health care information systems).

Key outcomes include not only clinical outcomes (typically defined as medical outcomes based on clinician assessment or diagnosis) — for example, PD-related infections, technique survival, mechanical complications, hospitalizations and PD-related mortality — but also patient-reported outcomes. These outcomes are directly reported by patients and focus on how they function or feel, typically in relation to quality of life or symptoms; patient-reported outcomes are used less frequently than clinical outcomes in day-to-day routine care.

Predictors and outcomes of peritoneal dialysis-related infections due to filamentous molds (MycoPDICS)

Introduction

We sought to evaluate the predictors and outcomes of mold peritonitis in patients with peritoneal dialysis (PD).

Methods

This cohort study included PD patients from the MycoPDICS database who had fungal peritonitis between July 2015-June 2020. Patient outcomes were analyzed by Kaplan Meier curves and the Log-rank test. Multivariable Cox proportional hazards model regression was used to estimating associations between fungal types and patients’ outcomes.

Results

The study included 304 fungal peritonitis episodes (yeasts n = 129, hyaline molds n = 122, non-hyaline molds n = 44, and mixed fungi n = 9) in 303 patients. Fungal infections were common during the wet season (p <0.001). Mold peritonitis was significantly more frequent in patients with higher hemoglobin levels, presentations with catheter problems, and positive galactomannan (a fungal cell wall component) tests. Patient survival rates were lowest for non-hyaline mold peritonitis. A higher hazard of death was significantly associated with leaving the catheter in-situ (adjusted hazard ratio [HR] = 6.15, 95%confidence interval [CI]: 2.86–13.23) or delaying catheter removal after the diagnosis of fungal peritonitis (HR = 1.56, 95%CI: 1.00–2.44), as well as not receiving antifungal treatment (HR = 2.23, 95%CI: 1.25–4.01) or receiving it for less than 2 weeks (HR = 2.13, 95%CI: 1.33–3.43). Each additional day of antifungal therapy beyond the minimum 14-day duration was associated with a 2% lower risk of death (HR = 0.98, 95%CI: 0.95–0.999).

Conclusion

Non-hyaline-mold peritonitis had worse survival. Longer duration and higher daily dosage of antifungal treatment were associated with better survival. Deviations from the 2016 ISPD Peritonitis Guideline recommendations concerning treatment duration and catheter removal timing were independently associated with higher mortality.

Characterization of Oral Enterobacteriaceae Prevalence and Resistance Profile in Chronic Kidney Disease Patients Undergoing Peritoneal Dialysis

Chronic Kidney Disease (CKD) is a growing public-health concern worldwide. Patients exhibit compromised immunity and are more prone to infection than other populations. Therefore, oral colonization by clinically relevant members of the Enterobacteriaceae family, major agents of both nosocomial and dialysis-associated infections with frequent prevalence of antibiotic resistances, may constitute a serious risk. Thus, this study aimed to assess the occurrence of clinically relevant enterobacteria and their antibiotic resistance profiles in the oral cavity of CKD patients undergoing peritoneal dialysis (CKD-PD) and compare it to healthy controls. Saliva samples from all the participants were cultured on MacConkey Agar and evaluated regarding the levels of urea, ammonia, and pH. Bacterial isolates were identified and characterized for antibiotic resistance phenotype and genotype. The results showed that CKD-PD patients exhibited significantly higher salivary pH, urea, and ammonia levels than controls, that was accompanied by higher prevalence and diversity of oral enterobacteria. Out of all the species isolated, only the prevalence of Raoultella ornithinolytica varied significantly between groups, colonizing the oral cavity of approximately 30% of CKD-PD patients while absent from controls. Antibiotic resistance phenotyping revealed mostly putative intrinsic resistance phenotypes (to amoxicillin, ticarcillin, and cephalothin), and resistance to sulfamethoxazole (~43% of isolates) and streptomycin (~17%). However, all isolates were resistant to at least one of the antibiotics tested and multidrug resistance isolates were only found in CKD-PD group (31,6%). Mobile genetic elements and resistance genes were detected in isolates of the species Raoultella ornithinolytica, Klebsiella pneumoniae, Klebsiella oxytoca, Escherichia coli, and Enterobacter asburiae, mostly originated from CKD-PD patients. PD-related infection history revealed that Enterobacteriaceae were responsible for ~8% of peritonitis and ~ 16% of exit-site infections episodes in CKD-PD patients, although no association was found to oral enterobacteria colonization at the time of sampling. The results suggest that the CKD-induced alterations of the oral milieu might promote a dysbiosis of the commensal oral microbiome, namely the proliferation of clinically relevant Enterobacteriaceae potentially harboring acquired antibiotic resistance genes. This study highlights the importance of the oral cavity as a reservoir for pathobionts and antibiotic resistances in CKD patients undergoing peritoneal dialysis.

Peritoneal Dialysis-Related Peritonitis: Rate, Clinical Outcomes and Patient Survival

Peritoneal dialysis-related peritonitis remains the major complication and primary challenge to the long-term success of peritoneal dialysis (PD). The study aimed to analyze the peritonitis rate, the cause, the outcomes, and the association of peritonitis with the survival of patients on peritoneal dialysis. Patient data were collected retrospectively from medical charts. A total of 96 patients received peritoneal dialysis in the PD center from 1 January 1999 to 31 December 2018. Episodes of peritonitis (n=159) were registered in 54 (56.3%) patients. The study population was divided into two groups, a group of patients (n=54) who experienced peritonitis and a group of patients free of peritonitis (n=42). The peritonitis rate was 0.47 episodes per patient year. The majority of causative microorganisms were gram-positive bacteria (53.5%). Outcomes of the episodes of peritonitis were resolved infection in 84.9% of episodes, catheter removal in 11.3% of episodes, and death in 3.8% of the episodes of peritonitis. A Kaplan-Meier analysis and log-rank test revealed that the group with peritonitis tended to survive significantly longer than the peritonitis-free group. A 67% reduction rate in the risk of patient mortality was observed for the peritonitis group compared with the peritonitis-free group (hazard ratio: 0.33, 95% CI 0.19-0.57, P=0.000). The prevention and management of PD-related infections, resulted in their worldwide reduction, supporting the use of PD as a first-line dialysis modality.

Roseomonas mucosa-Induced Peritonitis in a Patient Undergoing Continuous Cycler Peritoneal Dialysis: Case Report and Literature Analysis

Roseomonas species, a rare Gram-negative microorganism, has seldom been reported to cause peritonitis in end-stage renal disease patients on peritoneal dialysis. Only seven cases of peritonitis by this rare microorganism have been reported worldwide. Treatment options can be challenging if not detected early and can lead to significant morbidity and mortality along with the switching of the dialysis modality to hemodialysis which is highly undesirable. Our patient is a 65-year-old Caucasian female who needed to be changed to emergency hemodialysis due to inability to perform peritoneal dialysis from suspected peritonitis and was subsequently discovered to have peritonitis from Roseomonas mucosa. She recovered with a prolonged antibiotics course and returned to peritoneal dialysis in 3 months following her treatment completion. Prompt diagnosis and prolonged antibiotics are a cornerstone in the management of this rare microorganism to prevent mortality and morbidity from peritonitis.

The Emerging Uncommon Non-Albicans Candida: Candida Parapsilosis Peritonitis in a Peritoneal Dialysis Patient

Candida parapsilosis can cause invasive fungal infection which is associated with significant morbidity and mortality. Timely management of this uncommon Candida pathogen is essential to prevent peritoneal dialysis patients from succumbing to the infectious complications of peritonitis related to it. We present a 75-year-old Caucasian female with end-stage renal disease, on peritoneal dialysis at home, who presented with peritonitis features found to be related to this rare Candida species. She was treated with four weeks course of oral fluconazole and was switched to incenter hemodialysis. Physicians need to be aware of this notorious Candida species in peritoneal dialysis patients and prompt management is essential in successful patient outcomes.

Epidemiology, management, and prevention of exit site infections in peritoneal dialysis patients

Exit site infection (ESI) is a leading complication of peritoneal dialysis (PD), at an incidence of 0.6 episodes per year in the United States, and a major risk factor for catheter removal and peritonitis. An estimated 20% of all peritonitis cases are preceded by an ESI, with up to 50% of Staphylococcus aureus peritonitis associated with ESI. Gram-negative ESIs are less associated with succeeding peritonitis than their gram-positive counterparts, though when present, are associated with a lower peritonitis cure rate. The rate of catheter removal for refractory ESI is relatively highest in ESI due to mycobacteria (up to 40%), S. aureus (35%), Pseudomonas aeruginosa (28%), followed by Corynebacterium, Serratia, and fungi. In review of relevant literature, we found no prophylactic benefit of dressings over nondressings, specific antiseptics over normal saline, or topical honey over topical antibiotic prophylaxis, and thus recommend individualized exit site hygiene. We found topical gentamicin effective for prevention of most ESIs, including gram-negative ESIs, and thus recommend consideration of prophylactic topical gentamicin in areas of high gram-negative peritonitis incidence. With long-term use, observational studies detect up to 25% of gram-positive and 14% of gram-negative ESIs may be mupirocin and gentamicin resistant, respectively. We review empiric and targeted ESI management, including indications for ultrasound, anti-VMRSA, anti-Pseudomonal, and anti-mycobacterial antibiotic use, and catheter removal. We recommend further investigation into the earlier use of second-line treatment agents and the utility of treating post-infectious exit site colonization as avenues to decrease refractory and repeat ESI.

Safety of Endoscopy in Peritoneal Dialysis Patients

INTRODUCTION

Endoscopic procedures can provoke peritonitis in patients receiving peritoneal dialysis (PD). The aim of this study was to assess the development of peritonitis after endoscopic procedures in PD patients.

METHODS

We retrospectively reviewed the data from PD patients who underwent endoscopies in 3 tertiary hospitals between 2008 and 2018. The patients were grouped into nonprophylactic, prophylactic, and prior antibiotic therapy groups. The incidence of peritonitis within 7 days of endoscopy was assessed. We also examined the factors associated with peritonitis.

RESULTS

There were 1,316 endoscopies performed in 570 PD patients. The peritonitis rate after endoscopy was 3.0%. Specifically, the peritonitis rate was 1.8% for esophagogastroduodenoscopies, 4.2% for the colonoscopy group, and 5.3% for the sigmoidoscopy group. The prior antibiotic therapy group showed a significantly higher risk of peritonitis (odds ratio = 4.6; 95% confidence interval: 2.2-9.6; P < 0.01). Prophylactic antibiotics were not associated with reducing peritonitis. Therapeutic colonoscopies such as polypectomy were associated with an increased risk of developing peritonitis (odds ratio = 6.5; 95% confidence interval: 1.6-25.9). However, biopsies were not associated with an increased risk of peritonitis.

DISCUSSION

Prophylactic antibiotics did not reduce the risk of peritonitis after endoscopy in PD patients. Therapeutic colonoscopies such as polypectomy and prior antibiotic therapy before endoscopy were associated with an increased risk of peritonitis.

Two decades of analysis of peritonitis in peritoneal dialysis in Andalusia: Epidemiological, clinical, microbiological and progression aspects

BACKGROUND

This study focuses on the main complication associated with peritoneal dialysis, peritonitis. Its relevance derives from its high morbidity, the negative effect it has on the peritoneum as a dialysis membrane and its financial cost.

METHODS

Analytical, non-interventional, observational cohort study, whose main objective is the analysis of peritonitis in patients on peritoneal dialysis in Andalusia from 1 January 1999 to 31 December 2017, with a total of 2904 peritonitis cases. The database used is the Andalusian Autonomous Transplant Coordination Information System (SICATA).

OBJECTIVES

To ascertain how the rate of peritonitis is evolving in our community, analyse descriptive data pertaining to patients and peritonitis, ascertain the course of these infectious complications and analyse the factors that influence these cases of peritonitis and their outcomes: germ, hospitalisation and date.

RESULTS

The rate of peritonitis decreased progressively during the study period, from 0.7 peritonitis per patient in 1999 to 0.33 at the end of the period. Most infections were treated on an outpatient basis (72.5%). The most common germs were Gram-positive (55.9%), including coagulase-negative staphylococci (28.1%). Most cases of peritonitis progressed to healing (77.8%). The factors that significantly influence the need for hospitalisation and peritonitis progression were the causative germ and associated exit site infection.

CONCLUSIONS

In our population, the rate of peritonitis decreased progressively during the study period, meeting guideline recommendations.

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

RATIONALE & OBJECTIVE

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.

STUDY DESIGN

Observational prospective cohort study.

SETTING & PARTICIPANTS

1,631 peritonitis episodes (1,190 patients, 126 facilities) in Australia, New Zealand, Canada, Japan, Thailand, the United Kingdom, and the United States.

EXPOSURE

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).

OUTCOME

Cure, defined as absence of death, transfer to hemodialysis (HD), PD catheter removal, relapse, or recurrent peritonitis within 50 days of a peritonitis episode.

ANALYTICAL APPROACH

Mixed-effects logistic models.

RESULTS

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.

LIMITATIONS

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.

CONCLUSIONS

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.

Implementation of PDOPPS in a middle-income country: Early lessons from Thailand

BACKGROUND

Despite the implementation of a 'Peritoneal Dialysis (PD) First' policy in Thailand since 2008, nationwide PD practices and patients' outcomes have rarely been reported.

METHODS

As part of the multinational PD Outcomes and Practice Patterns Study (PDOPPS), PD patients from 22 PD centres from different geographic regions, sizes and affiliations, representing Thailand PD facilities, have been enrolled starting in May 2016. Demographic, clinical and laboratory data and patients' outcomes were prospectively collected and analysed.

RESULTS

The pilot and implementation phases demonstrated excellent concordance between study data and validation data collected at enrolment. In the implementation phase, 848 PD patients (including 262 (31%) incident PD patients) were randomly sampled from 5090 patients in participating centres. Almost all participants (95%) performed continuous ambulatory PD (CAPD), and a high proportion had hypoalbuminemia (67%, serum albumin < 3.5 g/dL), anaemia (42%, haemoglobin <10 g/dL) and hypokalaemia (37%, serum potassium < 3.5 mmol/L). The peritonitis rate was 0.40 episodes/year, but the culture-negative rate was high (0.13 episodes/year, 28% of total episodes). The patients from PD clinics located in Bangkok metropolitan region had higher socio-economic status, more optimal nutritional markers, blood chemistries, haemoglobin level and lower peritonitis rates compared to the provincial regions, emphasizing the centre effect on key success factors in PD.

CONCLUSIONS

Participation in the PDOPPS helps unveil the critical barriers to improving outcomes of PD patients in Thailand, including a high prevalence of hypokalaemia, anaemia, poor nutritional status and culture-negative peritonitis. These factors should be acted upon to formulate solutions and implement quality improvement on a national level.

Longer antibiotic durations for treating peritoneal dialysis-associated peritonitis: helpful or harmful?

Relapsing, recurrent or repeat peritonitis is a devastating complication for peritoneal dialysis (PD) patients and is usually associated with poor outcomes including prolonged hospitalization, catheter removal, hemodialysis transfer and even death. Despite its critical importance and frequent occurrence, there is limited available evidence to facilitate evidence-informed treatment of PD peritonitis. This editorial comments on the findings and limitations of a randomized controlled study published in this journal, which reported that extending antibiotic treatment duration for an additional week beyond that recommended by the International Society for PD did not reduce the risk of relapsing, recurrent or repeat peritonitis, and may have increased the risk of repeat peritonitis. These results are explored in the context of the existing literature and recommendations for practice and research are provided.

Variability in Culture-Negative Peritonitis Rates in Pediatric Peritoneal Dialysis Programs in the United States

BACKGROUND AND OBJECTIVES

International guidelines suggest a target culture-negative peritonitis rate of <15% among patients receiving long-term peritoneal dialysis. Through a pediatric multicenter dialysis collaborative, we identified variable rates of culture-negative peritonitis among participating centers. We sought to evaluate whether specific practices are associated with the variability in culture-negative rates between low- and high-culture-negative rate centers.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Thirty-two pediatric dialysis centers within the Standardizing Care to Improve Outcomes in Pediatric End Stage Renal Disease (SCOPE) collaborative contributed prospective peritonitis data between October 1, 2011 and March 30, 2017. Clinical practice and patient characteristics were compared between centers with a ≤20% rate of culture-negative peritonitis (low-rate centers) and centers with a rate >20% (high-rate centers). In addition, centers completed a survey focused on center-specific peritoneal dialysis effluent culture techniques.

RESULTS

During the 5.5 years of observation, 1113 patients had 1301 catheters placed, totaling 19,025 patient months. There were 620 episodes of peritonitis in 378 patients with 411 catheters; cultures were negative in 165 (27%) peritonitis episodes from 125 (33%) patients and 128 (31%) catheters. Low-rate centers more frequently placed catheters with a downward-facing exit site and two cuffs (P<0.001), whereas high-rate centers had more patients perform dialysis themselves without the assistance of an adult care provider (P<0.001). The survey demonstrated that peritoneal dialysis effluent culture techniques were highly variable across centers. No consistent practice or technique helped to differentiate low- and high-rate centers.

CONCLUSIONS

Culture-negative peritonitis is a frequent complication of maintenance peritoneal dialysis in children. Despite published recommendations for dialysis effluent collection and culture methods, great variability in culture techniques and procedures exists among individual dialysis programs and respective laboratory processes.

Optimizing Peritoneal Dialysis-Associated Peritonitis Prevention in the United States: From Standardized Peritoneal Dialysis-Associated Peritonitis Reporting and Beyond

Peritoneal dialysis (PD)-associated peritonitis is the leading cause of permanent transition to hemodialysis among patients receiving PD. Peritonitis is associated with higher mortality risk and added treatment costs and limits more widespread PD utilization. Optimizing the prevention of peritonitis in the United States will first require standardization of peritonitis definitions, key data elements, and outcomes in an effort to facilitate nationwide reporting. Standardized reporting can also help describe the variability in peritonitis rates and outcomes across facilities in the United States in an effort to identify potential peritonitis prevention strategies and engage with stakeholders to develop strategies for their implementation. Here, we will highlight considerations and challenges in developing standardized definitions and implementation of national reporting of peritonitis rates by PD facilities. We will describe existing peritonitis prevention evidence gaps, highlight successful infection-reporting initiatives among patients receiving in-center hemodialysis or PD, and provide an overview of nationwide quality improvement initiatives, both in the United States and elsewhere, that have translated into a reduction in peritonitis incidence. We will discuss opportunities for collaboration and expansion of the Nephrologists Transforming Dialysis Safety (NTDS) initiative to develop knowledge translation pathways that will lead to dissemination of best practices in an effort to reduce peritonitis incidence.

Two decades of analysis of peritonitis in peritoneal dialysis in Andalusia: Epidemiological, clinical, microbiological and progression aspects

BACKGROUND

This study focuses on the main complication associated with peritoneal dialysis, peritonitis. Its relevance derives from its high morbidity, the negative effect it has on the peritoneum as a dialysis membrane and its financial cost.

METHODS

Analytical, non-interventional, observational cohort study, whose main objective is the analysis of peritonitis in patients on peritoneal dialysis in Andalusia from 1 January 1999 to 31 December 2017, with a total of 2,904 peritonitis cases. The database used is the Andalusian Autonomous Transplant Coordination Information System (SICATA).

OBJECTIVES

To ascertain how the rate of peritonitis is evolving in our community, analyse descriptive data pertaining to patients and peritonitis, ascertain the course of these infectious complications and analyse the factors that influence these cases of peritonitis and their outcomes: germ, hospitalisation and date.

RESULTS

The rate of peritonitis decreased progressively during the study period, from 0.7 peritonitis per patient in 1999 to 0.33 at the end of the period. Most infections were treated on an outpatient basis (72.5%). The most common germs were Gram-positive (55.9%), including coagulase-negative staphylococci (28.1%). Most cases of peritonitis progressed to healing (77.8%). The factors that significantly influence the need for hospitalisation and peritonitis progression were the causative germ and associated exit site infection.

CONCLUSIONS

In our population, the rate of peritonitis decreased progressively during the study period, meeting guideline recommendations.

Long-term trends in the incidence of peritoneal dialysis-related peritonitis disclose an increasing relevance of streptococcal infections: A longitudinal study

Background

The selective impact of strategies for prevention of PD-related peritonitis (PDrP) may have modified, in the long term, the causal spectrum, clinical presentation and outcomes of these infections.

Objectives

To compare trends in the incidence of PDrP by different microorganisms during a 30-year period, with a particular focus on streptococcal infections. To analyze the clinical presentation and outcomes of these infections. Secondarily, to investigate how the isolation of different species of streptococci can influence the clinical course of PDrP by this genus of bacteria.

Method

Following a retrospective, observational design we investigated 1061 PDrP (1990–2019). We used joinpoint regression analysis to explore trends in the incidence of PDrP by different microorganisms, and compared the risk profile (Cox), clinical presentation and outcomes (logistic regression) of these infections.

Main results

Our data showed a progressive decline in the incidence of PDrP by staphylococci and Gram negative bacteria, while the absolute rates of streptococcal (average annual percent change +1.6%, 95% CI -0.1/+3.2) and polymicrobial (+1.8%, +0.1/+3.5) infections tended to increase, during the same period. Remarkably, streptococci were isolated in 58.6% of polymicrobial infections, and patients who suffered a streptococcal PDrP had a 35.8% chance of presenting at least one other infection by the same genus. The risk profile for streptococcal infections was comparable to that observed for PDrP overall. Streptococcal PDrP were associated with a severe initial inflammatory response, but their clinical course was generally nonaggressive thereafter. We did not observe a differential effect of different groups of streptococci on the clinical presentation or outcome of PDrP.

Conclusions

Time trends in the incidence of PDrP by different microorganisms have granted streptococci an increasing relevance as causative agents of these infections, during the last three decades. This behaviour suggests that current measures of prevention of PDrP may not be sufficiently effective, in the case of this genus of microorganisms.

Ochrobactrum Peritonitis: Case Report and Literature Review

End-stage kidney disease (ESKD) patients, including those on peritoneal dialysis (PD), are considered immunocompromised and at risk for opportunistic pathogens. Peritonitis is a major infectious PD complication with common causative pathogens, including gram-positive organisms such as coagulase-negative Staphylococcus species, Staphylococcus aureus more often than gram negative organisms. PD peritonitis is often secondary to suboptimal technique leading to contamination of the catheter site but can also be due to bacterial translocation from the bowel lumen or transient bacteremia after procedures; this makes identification of the causative organism crucial to optimal management of PD peritonitis. Ochrobactrum are glucose-non-fermentative, non-fastidious, motile gram-negative bacilli typically isolated in aqueous environments. Reported infections primarily occur in immunocompromised hosts with environmental exposure, including nosocomial contamination of fluids or indwelling catheters. We present only the seventh reported case of Ochrobactrum peritonitis in a 67-year-old PD patient secondary to poor technique, and review the literature for all prior cases. Although there have been no previous cases leading to bacteremia, three of the seven cases required removal of PD catheter.

The influence of seasonal factors on the incidence of peritoneal dialysis-associated peritonitis

OBJECTIVES

To investigate the effects of climatic variables on peritoneal dialysis-associated peritonitis (PDAP) among patients receiving PD, such as seasonal variations in temperature and humidity.

METHODS

A retrospective analysis was performed on PD patients, from 1 January 2011, to 31 December 2019. We evaluated the influence of seasonal factors on peritonitis rates and outcomes.

RESULTS

Over the 9-year study period, 667 peritonitis episodes occurred, in 401 PD patients. Diarrhea-associated peritonitis occurred more frequently in summer compared with other seasons. Eating raw and cold food was identified as the primary cause of peritonitis in the summer. More peritonitis episodes occurred during summer. The peritonitis rate associated with gram-negative bacteria (p = 0.050) during summer was higher than those in all other seasons. The gram-negative bacterial peritonitis rate was positively correlated with monthly mean temperature (r = 0.504, p < 0.01) and humidity (r = 0.561, p < 0.01). A similar trend was observed for Enterobacterial peritonitis (temperature: r = 0.518, p < 0.01; humidity: r = 0.456, p = 0.001). Logistic regression analysis showed that summer was a risk factor for peritonitis (p = 0.041). Peritonitis prognosis during summer was significantly worse than those for all other seasons (p = 0.037).

CONCLUSIONS

Seasonal variations exist in the incidence of dialysis-associated peritonitis, with peak incidents caused by gram-negative bacteria in the summer. High average temperature and humidity are associated with significant increases in the gram-negative bacteria and Enterobacterial peritonitis rates. Peritonitis prognosis during summer is worse.

The impact of the superficial cuff position on the exit site and tunnel infections in CAPD patients

BACKGROUND

Peritoneal dialysis (PD) related infections continue to be a major cause of morbidity and mortality in patients on PD. In the last ten years, in order to reduce cuff and exit-site infections, in continuous ambulatory peritoneal dialysis (CAPD) patients, we have positioned the superficial cuff subcutaneously 4 cm instead of 2 cm internal to the exit-site.

METHODS

We analysed the infective episodes occurred in 123 CAPD patients (88 men and 35 women, mean age 62.4 ± 16.8) treated for 3337 months between 1st January 2011 and 31th December 2018 at Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico.

RESULTS

31 of the 123 patients (25.2%) developed 52 episodes of exit site infection, with an incidence of 1 episode every 64.1 patient-months. The cumulative probability of remaining infection free was 80.7% at 12 months and 61.8% at 36 months. Gram-positive organism accounted for 78.7% of exit site infections. Forty-one episodes (87%) were successfully treated with medical therapy. Peritonitis incidence was 1 episode every 51.7 and 1 episode every 49.2 patient-months, in patients with or without a history of exit site infection respectively. The overall incidence of tunnel infection was 1 episode every 278.1 patient-months.

CONCLUSIONS

Positioning the superficial cuff subcutaneously at least 4 cm internal to the exit-site might prevent the bacterial cuff colonization and reduce ESIs, tunnel infections and peritonitis.

Peritoneal Dialysis-Associated Peritonitis: Suggestions for Management and Mistakes to Avoid

Peritonitis is a common complication of peritoneal dialysis that is associated with substantial morbidity and mortality. Peritonitis increases treatment costs and hospitalization events and is the most common reason for transfer to hemodialysis. Although there is much focus on preventing peritoneal dialysis–associated peritonitis, equally as important is appropriate management to minimize the morbidity of a peritonitis episode when it has occurred. Despite the presence of international guidelines on peritonitis treatment, the evidence base to support optimal peritonitis treatment practices is lacking, leaving the practitioner to rely on clinical experience and extrapolate from across other infection treatment practices. This article reviews common mistakes and misconceptions that we have observed in the management of peritonitis that may compromise treatment success. It also provides suggestions on common controversial aspects of peritonitis management based on the best available literature. Although the use of the word mistakes is somewhat controversial and subjective, we acknowledge that evidence is lacking and have based many of our suggestions on clinical judgment, experience, and available data.

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

BACKGROUND

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).

METHODS

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'.

RESULTS

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.

CONCLUSIONS

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.

Gastric Acid Suppression and the Risk of Enteric Peritonitis in Peritoneal Dialysis Patients

Objective

Peritonitis caused by enteric organisms in peritoneal dialysis (PD) patients is associated with greater morbidity and mortality than peritonitis with non-enteric organisms. One reported risk factor for enteric peritonitis (EP) is gastric acid suppression, with two small studies providing conflicting results. The objective of this study was to determine, using a larger patient population, whether gastric acid suppressants are associated with an increased risk of EP.

Patients and Methods

Using a single-center case-control design, information on episodes of EP occurring between 2003 and 2006 was collected. Control episodes were all non-enteric episodes of peritonitis that occurred during the same time interval. Proton pump inhibitor (PPI) or H2-blocker (H2B) use prior to development of peritonitis was documented.

Results

A total of 228 peritonitis episodes among 137 patients met inclusion criteria. In 32% of episodes, the causative organism was enteric. Gastric acid suppressant use was documented in 46% of episodes, with the majority on PPIs. Overall, gastric acid suppression was not associated with a higher EP risk ( p = 0.17). In a post hoc analysis, PPIs were not associated with EP [odds ratio (OR) 1.3, 95% confidence interval (CI) 0.7 – 2.4; p = 0.42], whereas H2Bs were associated with a higher risk of EP (OR 2.9, 95% CI 1.1 – 7.7; p = 0.04), although the number of patients on H2Bs was small.

Conclusion

Overall, gastric acid suppression was not associated with an increased risk of peritonitis with enteric organisms. While PPI use appears to be safe for PD patients with appropriate indications, the potential risk of EP with H2Bs requires further investigation.

A Randomized Controlled Trial Comparing Mupirocin versus Polysporin Triple for the Prevention of Catheter-Related Infections in Peritoneal Dialysis Patients (The MP3 Study)

Background

Peritonitis remains the most serious complication of peritoneal dialysis (PD). Gram-positive organisms are among the most common causes of PD peritonitis; however, recent trends show increasing rates of gram-negative and fungal infections. Strategies to prevent peritonitis include the use of prophylactic topical mupirocin at the site where the PD catheter exits from the abdominal wall; however, mupirocin does not afford protection against gram-negative or fungal infections. The aim of this study is to determine if the incidence of catheter-related infections (exit-site infection, tunnel infection, or peritonitis) is significantly reduced by the routine application of Polysporin Triple antibiotic ointment (Pfizer Canada, Markham, Ontario, Canada) in comparison to mupirocin ointment.

Methods and Design

The Mupirocin Versus Polysporin Triple Study (MP3) is a multicenter, randomized, double-blinded controlled study comparing Polysporin Triple (P3) against the current standard of care. The aim of the study is to recruit 200 patients being treated with or starting on PD and randomize them to receive either mupirocin or P3 at the catheter exit site. Patients will be followed for 18 months or until death or transfer from PD to an alternate treatment modality. The primary outcome will be the time to first catheter-related infection. Catheter-related infections will be strictly defined using current guidelines and categorized into exit-site infections, infective peritonitis, or tunnel infections. The primary analysis will be an intention-to-treat analysis.

Discussion

The results of this study will help determine if the use of P3 is superior to mupirocin ointment in the prevention of catheter-related infections and will help guide evidence-based best practices.

Peritonitis in Latin America

Peritoneal dialysis has a high acceptance rate in Latin America, thus the knowledge concerning complication patterns is of great relevance. This work reviews Latin American data on peritonitis, the most serious complication of peritoneal dialysis.

The incidence of peritonitis has been reduced over time, concomitantly with the incorporation of safer exchange systems and the use of prophylactic measurements. Today, rates lower than 1 episode per 24 patient-months are commonly reported. Furthermore, changes in causative organisms have been observed, with predominance of Staphylococcus aureus up through the mid-1990s, as well as increases in coagulase-negative staphylococcus and participation of gram negatives. However, the prevalence of S. aureus is still high, due possibly to climatic conditions and the elevated prevalence of carriers. Resolution rate varies from 55% to 78%, transfer to hemodialysis from 10.9% to 15.4%, and death in 3% to 9.9% of cases. Outcome is worse in S. aureus episodes compared to those with coagulase-negative staphylococcus, despite the higher percentage of oxacillin-resistant strains among the former. In general, despite socioeconomic or climatic conditions, our results are similar to those in developed countries, perhaps as a consequence of technological improvements and/or center expertise.

In-Center Intermittent Peritoneal Dialysis: Retrospective Ten-Year Single-Center Experience with Thirty Consecutive Patients

Background

In-center intermittent peritoneal dialysis (IPD) is sometimes performed in elderly and multimorbid patients that have failed hemodialysis and that are unable to perform peritoneal dialysis (PD) at home. Complications, frequency of hospital admission, and survival are often claimed to be dismal although current data are lacking.

Methods

We performed a retrospective cohort study of patients that underwent IPD at Hannover Medical School, Germany, between 1997 and 2007. Underlying renal disorders, comorbidity, and circumstances that precluded hemodialysis and home PD were recorded. Survival, cause of death, episodes of hospitalization, and episodes of peritonitis were calculated. Laboratory values at baseline and after 3 months of IPD were also retrieved.

Results

We identified 30 patients with severe comorbidity (median Charlson Comorbidity Index of 6; n = 30) who underwent IPD for 439 months in total. The majority of patients had vascular/hypertensive nephropathy ( n = 12; 40%); congestive heart failure was the leading cause for choosing PD ( n = 13; 43.3%); 73.3% of our patients had either no partner or at least one disease that precluded home therapy. Hospitalization rate was 1.39 admissions per patient-year and there was 1 episode of peritonitis per 48.8 IPD-months. Mean survival was 26.6 months (median 17 months; n = 30); sepsis was the leading cause of death ( n = 13; 59.1%).

Conclusions

IPD is associated with fewer episodes of peritonitis, fewer admissions, and longer survival than is often believed. Suitable patients in whom palliative care alone seems inappropriate should not be denied a trial of IPD if they so choose.

Pyridine levels in ceftazidime - peritoneal dialysis admixtures stored at body temperature

BACKGROUND

For the treatment of peritoneal dialysis-associated peritonitis (PDAP), ceftazidime is routinely admixed with peritoneal dialysis (PD) solutions before its intraperitoneal administration. One of the major degradation products of ceftazidime is pyridine, a potentially toxic compound. Depending on the type of PD solution, ceftazidime is exposed to an environment with acidic or basic pH, and depending on the type of dosing and individual unit practices related to preparation and storage, ceftazidime can be at body temperature for 4-10 h, resulting in potentially varying rates of degradation to pyridine by-product. No study has investigated whether the amount of generated pyridine exceeds the maximum daily exposure limit of 2 mg when ceftazidime-PD admixtures are kept at body temperature. Therefore, the current study aimed to determine the levels of pyridine generated in PD-ceftazidime admixtures kept at 37°C for various time points.

METHODS

Ceftazidime was admixed with 2 L Dianeal (1.5%, 2.5% and 4.25% dextrose) and 2 L Physioneal (1.36%, 2.27% and 3.86% glucose) PD solutions to obtain a concentration of 125 mg/L (continuous dosing model) or 500 mg/L (intermittent dosing model). A total of 36 PD admixtures (3 bags for each type of PD solution and 3 bags for each type of dosing) were prepared and stored at 37°C for 10 h. An aliquot was withdrawn at time 0 (baseline) and after 2, 6, 8 and 10 h of storage. The withdrawn samples were then analysed to determine the concentrations of ceftazidime and pyridine using high-performance liquid chromatography.

RESULTS

With the intermittent dosing model (500 mg/L), ceftazidime was found to be stable for only 2 and 6 h when admixed with 3.86% and 2.27% glucose Physioneal PD solutions, respectively. While ceftazidime (500 mg/L) retained more than 90% of its initial concentration in the three types of Dianeal and 1.36% dextrose Physioneal solutions for 10 and 8 h, respectively, the generated amount of pyridine ranged between approximately 290% and 371% more than the daily recommended limit. With the continuous dosing model (125 mg/L), ceftazidime was found to be stable for 6 h in all three types of Physioneal PD solutions, but the total amount of generated pyridine with four daily exchanges (6 h each) was estimated to be 170-360% over the daily recommended limit. Ceftazidime (125 mg/L) was chemically stable when admixed with three types of Dianeal PD solutions and stored at 37°C for 10 h, and the levels of pyridine were estimated to be less than the maximum recommended daily limit.

CONCLUSIONS

Until the outcomes of this in vitro study are confirmed by appropriate in vivo studies, continuous dosing of ceftzadime-Dianeal admixtures for the treatment of PDAP may be preferred over continuous dosing of ceftazidime-Physioneal admixtures, and intermittent dosing of ceftazidime-Physioneal and ceftazidime-Dianeal admixtures, as ceftazidime remains stable and the generated levels of pyridine are below the maximum recommended daily exposure.

Stability of ceftolozane and tazobactam in different peritoneal dialysis solutions

BACKGROUND

Peritonitis is a common and serious complication of peritoneal dialysis (PD). PD-associated peritonitis (PDAP) caused by Pseudomonas is usually resistant to most antibiotics, resulting in high failure rates. Ceftolozane/tazobactam (C/T) has been shown to be effective in treating urinary tract and intra-abdominal infections caused by beta-lactam resistant Pseudomonas and other gram-negative bacteria. Given its favourable adverse effects profile, it has a potential role in the treatment of PDAP caused by Pseudomonas species resistant to other antibiotics. Intraperitoneal administration of antibiotics admixed with PD solutions for the treatment of PDAP is associated with superior outcomes. However, there is a lack of published data on the stability of C/T in PD solutions. Therefore, this study investigated the physical and chemical stability of C/T in commonly used PD solutions at different temperatures.

METHODS

A total of 27 PD bags (3 PD bags for each type of PD solution including Dianeal®, Extraneal®, Balance® and Physioneal® PD bags) containing C/T were prepared and stored at 25°C for 6 h, followed by 4°C for 168 h and then 37°C for 12 h. An aliquot from each PD bag was withdrawn, and the concentration of C/T before (0 h) and after predefined time points was determined using a stability-indicating high-performance liquid chromatography assay. Samples were also assessed for pH, colour change and particulate matter immediately after preparation and on each day of analysis.

RESULTS

C/T retained more than 97% of their initial concentration when stored at 25°C for 6 h followed by storage at 4°C for 168 h and then at 37°C for 12 h. Particle formation was not detected at any time under the tested storage conditions. The pH and colour remained essentially unchanged throughout the study.

CONCLUSIONS

These results provide a platform for clinical studies to determine the safety and therapeutic efficacy of intraperitoneal C/T for the treatment of PDAP caused by resistant Pseudomonas species.

Microbiological Trends and Antimicrobial Resistance in Peritoneal Dialysis-Related Peritonitis, 2005 to 2014

Background

Information related to the microbiology of peritonitis is critical to the optimal management of patients receiving peritoneal dialysis (PD). The goal was to characterize the microbiological etiology and antimicrobial susceptibilities of PD-related peritonitis (PDRP) from 2005 to 2014, inclusive.

Methods

The distribution of organisms in culture-positive PDRP was described for new episodes and relapse infections, and further detailed for monomicrobial and polymicrobial peritonitis. Annual and overall rates of PDRP were also characterized. Antimicrobial susceptibility rates were calculated for the most common and significant organisms.

Results

We identified 539 episodes of PDRP including 501 new and 38 relapse infections. New episodes of peritonitis were associated with a single organism in 85% of cases, and 44% of those involved staphylococci. Polymicrobial PDRP was more likely to involve gram-negative organisms, observed in 58% versus 24% of monomicrobial infections. Antimicrobial resistance was relatively stable from 2005 to 2014. Methicillin resistance was present in 57% of Staphylococcus epidermidis and 20% of other coagulase-negative staphylococci. Methicillin-resistant Staphylococcus aureus (MRSA) accounted for only 11% of S. aureus peritonitis compared with 2% in our previous study of PDRP from 1991 to 1998. Ciprofloxacin resistance in Escherichia coli increased from 3% in our previous study to 24% in 2005 – 2014.

Conclusions

This study characterizes important differences in the distribution of organisms in new episodes of PDRP and relapse infections, as well as monomicrobial versus polymicrobial peritonitis. It also shows relatively stable rates of antimicrobial resistance from 2005 to 2014, but some increases compared with our previous study.

Infection Prophylaxis in Peritoneal Dialysis Patients: Results from an Australia/New Zealand Survey

Background

Clinical practice guidelines aim to reduce the rates of peritoneal dialysis (PD)-related infections, a common complication of PD in end-stage kidney disease patients. We describe the clinical practices used by Australian and New Zealand nephrologists to prevent PD-related infections in PD patients.

Methods

A survey of PD practices in relation to the use of antibiotic and antifungal prophylaxis in PD patients was conducted of practicing nephrologists identified via the Australia and New Zealand Society of Nephrology (ANZSN) membership in 2013.

Results

Of 333 nephrologists approached, 133 (39.9%) participated. Overall, 127 (95.5%) nephrologists prescribed antibiotics at the time of Tenckhoff catheter insertion, 85 (63.9%) routinely screened for nasal S. aureus carriage, with 76 (88.4%) reporting they treated S. aureus carriers with mupirocin ointment. Following Tenckhoff catheter insertion, 79 (59.4%) prescribed mupirocin ointment at the exit site or intranasally, and 93 (69.9%) nephrologists routinely prescribed a course of oral antifungal agent whenever their PD patients were given a course of antibiotics.

Conclusions

Although the majority of nephrologists prescribe antibiotics at the time of Tenckhoff catheter insertion, less than 70% routinely prescribe mupirocin ointment and/or prophylactic antifungal therapy. This variation in practice in Australia and New Zealand may contribute to the disparity in PD-related infection rates that is seen between units.

Review of Antibiotic Dosing with Peritonitis in APD

Peritonitis is the leading cause of transfer from peritoneal dialysis (PD) to hemodialysis (HD). It is also the leading cause of hospitalization of PD patients. The usual treatment of peritonitis for automated PD (APD) patients consists of antibiotics given once daily in the long dwell. However, the once-daily antibiotic dosing recommendations are based primarily on studies with continuous ambulatory PD (CAPD) regimens. Published studies on antibiotic dosing in APD are very limited. We will review the scant literature on this topic. It is possible that extrapolating once-daily dosing from CAPD to APD may lead to underdosing. There is a need for further pharmacokinetic studies of antibiotic dosing in APD.

Peritoneal dialysis-associated peritonitis outcomes reported in trials and observational studies: A systematic review

BACKGROUND

Peritoneal dialysis (PD)-associated peritonitis carries significant morbidity, mortality, and is a leading cause of PD technique failure. This study aimed to assess the scope and variability of PD-associated peritonitis reported in randomized trials and observational studies.

METHODS

Cochrane Controlled Register of Trials, MEDLINE, and Embase were searched from 2007 to June 2018 for randomized trials and observational studies in adult and pediatric patients on PD that reported PD-associated peritonitis as a primary outcome or as a part of composite primary outcome. We assessed the peritonitis definitions used, characteristics of peritonitis, and outcome reporting and analysis.

RESULTS

Seventy-seven studies were included, three were randomized trials. Thirty-eight (49%) of the included studies were registry-based observational studies. Twenty-nine percent (n = 22) of the studies did not specify how PD-associated peritonitis was defined. Among those providing a definition of peritonitis, three components were reported: effluent cell count (n = 42, 54%), clinical features consistent with peritonitis (e.g. abdominal pain and/or cloudy dialysis effluent) (n = 35, 45%), and positive effluent culture (n = 19, 25%). Of those components, 1 was required to make the diagnosis in 6 studies (8%), 2 out of 2 were required in 22 studies (29%), 2 out of 3 in 11 studies (14%), and 3 out of 3 in 4 studies (5%). Peritonitis characteristics and outcomes reported across studies included culture-negative peritonitis (n = 47, 61%), refractory peritonitis (n = 42, 55%), repeat peritonitis (n = 9, 12%), relapsing peritonitis (n = 5, 7%), concomitant exit site (n = 16, 21%), and tunnel infections (n = 8, 10%). Peritonitis-related hospitalization was reported in 38% of the studies (n = 29), and peritonitis-related mortality was variably defined and reported in 55% of the studies (n = 42). Peritonitis rate was most frequently reported as episodes per patient year (n = 40, 52%).

CONCLUSION

Large variability exists in the definitions, methods of reporting, and analysis of PD-associated peritonitis across trials and observational studies. Standardizing definitions for reporting of peritonitis and associated outcomes will better enable assessment of the comparative effect of interventions on peritonitis. This will facilitate continuous quality improvement measures through reliable benchmarking of this patient-important outcome across centers and countries.

Peritoneal Dialysis-Related Infection Rates and Outcomes: Results From the Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS)

RATIONALE & OBJECTIVE

Peritoneal dialysis (PD)-related peritonitis carries high morbidity for PD patients. Understanding the characteristics and risk factors for peritonitis can guide regional development of prevention strategies. We describe peritonitis rates and the associations of selected facility practices with peritonitis risk among countries participating in the Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS).

STUDY DESIGN

Observational prospective cohort study.

SETTING & PARTICIPANTS

7,051 adult PD patients in 209 facilities across 7 countries (Australia, New Zealand, Canada, Japan, Thailand, United Kingdom, United States).

EXPOSURES

Facility characteristics (census count, facility age, nurse to patient ratio) and selected facility practices (use of automated PD, use of icodextrin or biocompatible PD solutions, antibiotic prophylaxis strategies, duration of PD training).

OUTCOMES

Peritonitis rate (by country, overall and variation across facilities), microbiology patterns.

ANALYTICAL APPROACH

Poisson rate estimation, proportional rate models adjusted for selected patient case-mix variables.

RESULTS

2,272 peritonitis episodes were identified in 7,051 patients (crude rate, 0.28 episodes/patient-year). Facility peritonitis rates were variable within each country and exceeded 0.50/patient-year in 10% of facilities. Overall peritonitis rates, in episodes per patient-year, were 0.40 (95% CI, 0.36-0.46) in Thailand, 0.38 (95% CI, 0.32-0.46) in the United Kingdom, 0.35 (95% CI, 0.30-0.40) in Australia/New Zealand, 0.29 (95% CI, 0.26-0.32) in Canada, 0.27 (95% CI, 0.25-0.30) in Japan, and 0.26 (95% CI, 0.24-0.27) in the United States. The microbiology of peritonitis was similar across countries, except in Thailand, where Gram-negative infections and culture-negative peritonitis were more common. Facility size was positively associated with risk for peritonitis in Japan (rate ratio [RR] per 10 patients, 1.07; 95% CI, 1.04-1.09). Lower peritonitis risk was observed in facilities that had higher automated PD use (RR per 10 percentage points greater, 0.95; 95% CI, 0.91-1.00), facilities that used antibiotics at catheter insertion (RR, 0.83; 95% CI, 0.69-0.99), and facilities with PD training duration of 6 or more (vs <6) days (RR, 0.81; 95% CI, 0.68-0.96). Lower peritonitis risk was seen in facilities that used topical exit-site mupirocin or aminoglycoside ointment, but this association did not achieve conventional levels of statistical significance (RR, 0.79; 95% CI, 0.62-1.01).

LIMITATIONS

Sampling variation, selection bias (rate estimates), and residual confounding (associations).

CONCLUSIONS

Important international differences exist in the risk for peritonitis that may result from varied and potentially modifiable treatment practices. These findings may inform future guidelines in potentially setting lower maximally acceptable peritonitis rates.

Resuming peritoneal dialysis after catheter removal due to complicated peritonitis

BACKGROUND

Causes of non-resuming peritoneal dialysis (PD) after complicated peritonitis requiring peritoneal catheter (PC) removal remain poorly studied.

METHODS

We reviewed all peritonitis episodes in our center between 1997 and 2017. Patients who restarted PD after PC removal (Group 1) were compared to those who did not (Group 2), identifying the causes.

RESULTS

Of 284 peritonitis episodes, PC was removed in 48 patients (16.9%). In 18 (37.5%) patients PC was reinserted, and PD successfully resumed in all, with a median duration of PD afterwards of 14.1 months. In other 30 (62.5%) reinsertion of PC was not attempted. Causes of non-reinsertion were: transfer to hemodialysis 76.6% (n = 23), death 16.7% (n = 5) and transplantation 6.7% (n = 2). Hemodialysis switch was due to non-medical reasons in 47.8% (n = 11) including fear of peritonitis, family decision and social dependence. Group 1 was younger (p = 0.041), with lower Charlson index (p = 0.045) and higher men proportion (p = 0.049). Group 1 had a better patient survival than group 2 (survival at 24 months: 67% and 53%, respectively; log-rank test p: 0.01). There were no differences in survival between groups when adjusted for significant basal characteristics.

CONCLUSIONS

Resuming PD after severe peritonitis requiring PC removal is feasible but a high proportion of patients do not restart PD for non-medical reasons, usually older patients with higher Charlson index. A properly structured interview would be a useful tool that could improve return to technique in these patients.