Peritoneal dialysis peritonitis due to Neisseria: clinicopathological features of 10 patients with a review of the literature

BACKGROUND

Peritoneal dialysis-associated peritonitis (PDAP) frequently arises as a complication in patients undergoing peritoneal dialysis. However, the understanding of the role of Neisseria, a gram-negative coccus, in PDAP is limited.

METHODS

This study retrospectively analyzed data for patients with Neisseria-associated PDAP who were treated at our center from January 2010 to June 2022. These patients were classified into the Neisseria group (Group N) and matched 1:2 by sex, age, dialysis duration, and residual kidney Kt/V with a coagulase-negative staphylococci group (Group CNS) and a Staphylococcus aureus group (Group S) as controls. Statistical analysis was conducted via SPSS 25.0 and was supplemented with a review of the relevant literature, to investigate clinical features, pathways of infection, and patient outcomes.

RESULTS

This study included 10 cases of Neisseria-associated PDAP, comprising 6 male and 4 female patients. The patients had an average age of 58.10 ± 14.52 years, and the average duration of peritoneal dialysis was 72.00 ± 46.99 months. Among these patients, 3 had first-time infections, while 7 had a prior history of PDAP. After treatment, 9 patients achieved medical cure, and 1 patient was transferred to hemodialysis (HD). Baseline comparisons across the 3 groups indicated notable differences in body temperature upon admission, which were statistically significant (p < 0.05), with patients in Group S having higher body temperatures compared to Group N and Group CNS. Compared with Group N, Group S presented a markedly elevated high-sensitivity C-reactive protein (hs-CRP) level, decreased serum albumin levels, reduced serum potassium levels, whereas Group CNS presented a significantly lower neutrophil percentage (N%) than did Group N (p < 0.05). Although survival analysis did not reveal statistically significant differences due to the limited sample size, Kaplan-Meier curves indicated a trend toward lower cure rates and slightly worse long-term outcomes in Group S than in Group N and Group CNS, with the latter 2 groups showing similar results.

CONCLUSION

Neisseria-associated PDAP generally has favorable outcomes, similar to those of CNS-related PDAP and better than those of S-related PDAP. Hypoalbuminemia, hypokalemia and elevated hs-CRP are key risk factors affecting outcomes, emphasizing the need to address them during treatment.

Risk Factors of the Occurrence and Treatment Failure of Refractory Peritoneal Dialysis-Associated Peritonitis: A Single-Center Retrospective Study From China

BACKGROUND

This study aimed to investigate the clinical characteristics and prognosis of refractory peritoneal dialysis (PD)-associated peritonitis as well as the risk factors of its occurrence and treatment failure.

METHODS

A single-center retrospective cohort study was conducted among 519 patients undergoing PD from January 2007 to October 2021. According to the International Society for Peritoneal Dialysis guidelines, all episodes occurred in our center were divided into two groups: refractory and nonrefractory. Demographic, biochemical, and pathogenic bacteria and treatment outcome data were collected.

RESULTS

During the 15-year period, 282 episodes of peritonitis occurred in 166 patients undergoing PD. The refractory rate was 34.0% (96/282). Gram-positive organisms were the leading cause of peritonitis (47.9%); however, gram-negative organisms were predominant in refractory peritonitis (34.4%, p = 0.002). Multiple logistic regression revealed that gram-negative organism-based peritonitis, longer PD duration, and female sex were the significant independent predictors of refractory peritonitis. Among 96 refractory episodes, white blood cell (WBC) count, dialysate WBC on Day 3, and PD duration ≥5 years were the independent risk factors of treatment failure.

CONCLUSIONS

Gram-negative organism-based peritonitis, longer PD duration, and female sex were the independent risk factors of refractory peritonitis. Refractory peritonitis with higher WBC count, higher dialysate WBC on Day 3, and PD duration ≥5 years increased treatment failure risk and required immediate PD catheter removal. The timely identification of refractory peritonitis with high risk of treatment failure as well as timely PD catheter removal is important.

Clinical characteristics and antibiotic treatment of peritoneal dialysis-associated peritonitis caused by Pseudomonas species: a review of 15 years' experience from southern China

Pseudomonas can lead to peritoneal dialysis-associated peritonitis, which is characterized by a poor prognosis, such as a substantial failure rate and a high death rate. This study aimed to provide an overview of Pseudomonas peritonitis's clinical features, the regimens of antibiotic, antibiotic resistance, and outcomes in peritoneal dialysis (PD) patients. This study observed patients with Pseudomonas peritonitis in two large PD centers in South China from January 2008 to December 2022. The demographics, symptomatology, antibiotics regimens, resistance to common antibiotics, and clinical outcomes of all included patients were reviewed. A total of 3,459 PD patients were included, among them 57 cases of peritonitis caused by Pseudomonas, including 48 cases (84.2%) of Pseudomonas aeruginosa. The incidence rate of Pseudomonas peritonitis was 0.0041 episode per patient-year. Of them, 28.1% (16 cases) of the patients were accompanied by exit site infection (ESI), and all had abdominal pain and turbid ascites at the time of onset. The most commonly used antibiotic combination was ceftazidime combined with amikacin. Approximately 89% of Pseudomonas species were sensitive to ceftazidime, and 88% were sensitive to amikacin. The overall primary response rate was 28.1% (16 patients), and the complete cure rate was 40.4% (23 patients). There was no significant difference in the complete cure rate of peritonitis using three and other antibiotic treatment regimens (44.8% vs 46.4%; P = 0.9). The successful treatment group had higher baseline albumin level (35.9 ± 6.2; P = 0.008) and residual urine volume (650.7 ± 375.5; P = 0.04). Although the incidence of peritonitis caused by Pseudomonas was low, the symptoms were serious, and prognosis was very poor. Pseudomonas was still highly susceptible to first-line antibiotics currently in use against Gram-negative bacteria. Patients with successful treatment had higher albumin levels and higher urine output.

IMPORTANCE

Although the incidence of peritoneal dialysis-associated peritonitis caused by Pseudomonas is very low, it seriously affects the technique survival of peritoneal dialysis patients. However, there are few studies and reports on Pseudomonas peritonitis in the Chinese mainland area. Therefore, the purpose of this study is to describe the clinical characteristics, the regimens of antibiotic, drug resistance, and outcome of peritoneal dialysis patients in southern China in the past 15 years and summarize the clinical experience in the treatment of Pseudomonas peritonitis.

Random forest can accurately predict the technique failure of peritoneal dialysis associated peritonitis patients

Instructions

Peritoneal dialysis associated peritonitis (PDAP) is a major cause of technique failure in peritoneal dialysis (PD) patients. The purpose of this study is to construct risk prediction models by multiple machine learning (ML) algorithms and select the best one to predict technique failure in PDAP patients accurately.

Methods

This retrospective cohort study included maintenance PD patients in our center from January 1, 2010 to December 31, 2021. The risk prediction models for technique failure were constructed based on five ML algorithms: random forest (RF), the least absolute shrinkage and selection operator (LASSO), decision tree, k nearest neighbor (KNN), and logistic regression (LR). The internal validation was conducted in the test cohort.

Results

Five hundred and eight episodes of peritonitis were included in this study. The technique failure accounted for 26.38%, and the mortality rate was 4.53%. There were resignificant statistical differences between technique failure group and technique survival group in multiple baseline characteristics. The RF prediction model is the best able to predict the technique failure in PDAP patients, with the accuracy of 93.70% and area under curve (AUC) of 0.916. The sensitivity and specificity of this model was 96.67 and 86.49%, respectively.

Conclusion

RF prediction model could accurately predict the technique failure of PDAP patients, which demonstrated excellent predictive performance and may assist in clinical decision making.

The Association Between Serum Vancomycin Level and Clinical Outcome in Patients With Peritoneal Dialysis Associated Peritonitis

Introduction

Intraperitoneal (IP) vancomycin is often first-line empiric therapy and then maintenance therapy for peritoneal dialysis (PD) peritonitis. However, how vancomycin serum levels correlate with clinical outcomes remains unclear.

Methods

We conducted a retrospective single-center adult cohort study of 98 patients with PD peritonitis treated with IP vancomycin between January 2016 and May 2022. The association between nadir vancomycin level and cure was evaluated in a logistic regression model, first unadjusted and then adjusted for age, sex, weight, glomerular filtration rate (GFR), and total number of days on PD. Vancomycin was assessed both as a continuous exposure (per 1 mg/l increase) and as a categorical exposure (<15 mg/l vs. ≥15 mg/l). A receiver operating characteristic curve (ROC) was created to explore nadir vancomycin level thresholds in an attempt to identify an optimal target level during treatment.

Results

Of the patients, 81% achieved cure, and patients with nadir vancomycin level ≥15 mg/l were 7.5 times more likely to experience cure compared to those with a nadir level <15 mg/l (odds ratio [OR] 7.58, 95% confidence interval [CI] 1.71-33.57, P = 0.008). Weight, GFR, days on PD, sex, and age were not independently associated with outcome. The vancomycin level with the greatest discriminatory capacity for cure on the ROC analysis was 14.4 mg/l.

Conclusion

Increasing IP vancomycin serum levels are associated with increased odds of cure; and maintaining vancomycin serum levels above 14-15 mg/l throughout the course of PD peritonitis treatment is likely to improve clinical outcomes.

Effect of different dialysis duration on the prognosis of peritoneal dialysis-associated peritonitis: a single-center, retrospective study

BACKGROUND

Peritoneal dialysis (PD)-associated peritonitis is a serious complication observed in peritoneal dialysis patients. Herein, we investigated the clinical characteristics and treatment outcomes of PD peritonitis in patients with different PD durations.

METHODS

All peritonitis episodes from January 2007 to December 2020 at Peking University People's hospital PD center were retrospectively analyzed and divided into the long-dialysis duration (≥60 months, LDD) and short-dialysis duration (<60 months, SDD) groups. Clinical characteristics and outcomes were compared between these groups. The risk factors for treatment failure were analyzed using a logistic regression model.

RESULTS

During 14 years, 156 patients had 267 peritonitis episodes. There were 83 (31.1%) peritonitis episodes in the LDD group and 184 (68.9%) in the SDD group. No statistical difference was noted in peritonitis causes and the composition of causative pathogens between the two groups. The hospitalization, treatment failure, and transfer-to-hemodialysis rates, and peritonitis-related mortality were significantly higher in the LDD group than in the SDD group (all p < .05). Logistic regression analysis revealed that PD duration was an independent risk factor for PD-associated hospitalization, treatment failure and peritonitis-related death (p < .05). The receiver operating characteristic curve analysis results showed that when the cutoff value of PD duration was 5.5 years, the sensitivity of predicting PD peritonitis treatment failure was 51.1%, specificity was 78.8%, and the area under the curve was 0.679 (95% confidence interval: 0.594-0.765, p < .001).

CONCLUSIONS

PD duration is an independent risk factor for poor prognosis in PD peritonitis. Careful and active attention should be paid to the prevention of peritonitis in PD patients with long PD duration.

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).

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.

Microbiology and outcomes of polymicrobial peritonitis associated with peritoneal dialysis: a register-based cohort study from the French Language Peritoneal Dialysis Registry (RDPLF)

BACKGROUND

Previous studies have reported that polymicrobial peritonitis in peritoneal dialysis (PD) is associated with poor outcomes, but recent data from European cohorts are scarce.

METHODS

We included from the French Language Peritoneal Dialysis Registryall patients ≥ 18 years who started PD between January 2014 and November 2020. We compared microbiology and patient characteristics associated with mono- and polymicrobial peritonitis. We assessed patient outcomes after a first polymicrobial peritonitis using survival analysis with competing events. We differentiated microorganisms isolated from dialysis effluent as enteric or non-enteric pathogens.

RESULTS

8848 patients contributed 13 023 patient-years of follow-up and 3348 culture-positive peritonitis, including 251 polymicrobial ones. This corresponded to rates of 0.32 and 0.02 episodes/patient-year, respectively. For most patients (72%) who experienced polymicrobial peritonitis, this was their first peritonitis episode. Enteric pathogens were more frequently isolated in poly- than in monomicrobial peritonitis (57 vs 44%, P < 0.001). In both cases of peritonitis with or without enteric pathogens, the poly- versus monomicrobial character of the peritonitis was not associated with mortality in patients who did not switch to hemodialysis (adjusted cause-specific hazard ratio, a.cs-HR, 1.2 [95% CI, 0.3-5.0], P = 0.78 and 1.1 [0.7-1.8], P = 0.73, respectively). However, the risks of death and switch to hemodialysis were higher for monomicrobial peritonitis with enteric pathogens, compared to those without (a.cs-HR, 1.3 [1.1-1.7], P = 0.02 and 1.9 [1.5-2.4], P < 0.0001, respectively).

CONCLUSION

Isolation of enteric pathogens, rather than the polymicrobial character of the peritonitis, is associated with poorer outcomes.

Development and Validation of a Prediction Model for the Cure of Peritoneal Dialysis-Associated Peritonitis: A Multicenter Observational Study

Aim

Peritoneal dialysis (PD)-associated peritonitis (PDAP) is a severe complication of PD. It is an important issue about whether it can be cured. At present, there is no available prediction model for peritonitis cure. Therefore, this study aimed to develop and validate a prediction model for peritonitis cure in patients with PDAP.

Methods

Patients with PD who developed PDAP from four dialysis centers in Northeast China were followed up. According to the region of PD, data were divided into training and validation datasets. Initially, a nomogram for peritonitis cure was established based on the training dataset. Later, the nomogram performance was assessed by discrimination (C-statistic), calibration, and decision curves.

Results

Totally, 1,011 episodes of peritonitis were included in the final analysis containing 765 in the training dataset and 246 in the validation dataset. During the follow-up period, peritonitis cure was reported in 615 cases from the training dataset and 198 from the validation dataset. Predictors incorporated in the final nomogram included PD duration, serum albumin, antibiotics prior to admission, white cell count in peritoneal dialysate on day 5 (/μl) ≥ 100/μl, and type of causative organisms. The C-statistic values were 0.756 (95% CI: 0.713–0.799) in the training dataset and 0.756 (95% CI: 0.681–0.831) in the validation dataset. The nomogram exhibited favorable performance in terms of calibration in both the training and validation datasets.

Conclusion

This study develops a practical and convenient nomogram for the prediction of peritonitis cure in patients with PDAP, which assists in clinical decision-making.

[Development and validation of a prediction model for treatment failure in peritoneal dialysis-associated peritonitis patients: a multicenter study]

OBJECTIVE

To develop and validate a risk prediction model of treatment failure in patients with peritoneal dialysis-associated peritonitis (PDAP).

METHODS

We retrospectively analyzed the data of patients undergoing peritoneal dialysis (PD) in 3 dialysis centers in Jilin Province who developed PDAP between January 1, 2013 and December 31, 2019. The data collected from the Second Hospital of Jilin University and Second Division of First Hospital of Jilin University) were used as the training dataset and those from Jilin Central Hospital as the validation dataset. We developed a nomogram for predicting treatment failure using a logistic regression model with backward elimination. The performance of the nomogram was assessed by analyzing the C-statistic and the calibration plots. We also plotted decision curves to evaluate the clinical efficacy of the nomogram.

RESULTS

A total of 977 episodes of PDAP were included in the analysis (625 episodes in the training dataset and 352 episodes in the validation dataset). During follow-up, 78 treatment failures occurred in the training dataset and 35 in the validation dataset. A multivariable logistic regression prediction model was established, and the predictors in the final nomogram model included serum albumin, peritoneal dialysate white cell count on day 5, PD duration, and type of causative organisms. The nomogram showed a good performance in predicting treatment failure, with a C-statistic of 0.827 (95% CI: 0.784-0.871) in the training dataset and of 0.825 (95% CI: 0.743-0.908) in the validation dataset. The nomogram also performed well in calibration in both the training and validation datasets.

CONCLUSION

The established nomogram has a good accuracy in estimating the risk of treatment failure in PDAP patients.

Phenotypic and Molecular Characterization of Nonfermenting Gram-Negative Bacilli Causing Peritonitis in Peritoneal Dialysis Patients

(1) Background: Peritonitis due to nonfermenting Gram-negative bacilli (NF-GNB) is a dramatic complication of peritoneal dialysis (PD) with bad outcomes. Previous studies of PD-related peritonitis due to Pseudomonas species have shown a low-resolution rate, without a high resistance rate to antipseudomonal antibiotics. This suggests that bacterial virulence factors can act and influence peritonitis evolution. This study aimed to describe the microbiological characteristics of NF-GNB causing PD-related peritonitis and analyze their influence on the outcome. (2) Methods: We analyze the 48 isolates from NF-GNB peritonitis, which were stored in our culture collection regarding bacterial resistance, biofilm, and other virulence factors’ production, and clonal profile. Additionally, we collected data on treatment and outcomes from patients’ clinical registers. (3) Results: The etiologies were species of Pseudomonas (50%), Acinetobacter (36%), and other NF-GNB (14%). There was a high (75%) proportion of biofilm producer lineages. The in vitro susceptibility rate of Pseudomonas spp. to amikacin, ciprofloxacin, and ceftazidime was significantly greater than that of Acinetobacter spp. and other species; however, there was a similar low-resolution rate (<45%) among the episodes attributable to them. Pseudomonas species have a polyclonal profile, while we found a clone of five multiresistant Acinetobacter baumannii over an 8-year interval (2000–2008), which suggest an origin from the healthcare environment. (4) Conclusions: We are not able to identify any predictor of outcome, but it is possible that biofilm and others virulence factors can act in concert and contribute to the bad outcome.

Peritoneal dialysis-related peritonitis caused by gram-negative organisms: ten-years experience in a single center

Objectives

Concerns are increasing about the clinical characteristics of gram- negative bacterial peritonitis for providing reference for clinical diagnosis, treatment and prevention.

Methods

A retrospective analysis was performed examining patients who developed peritoneal dialysis-related peritonitis (PDRP) from 1 January 2009 to 31 December 2018.

Results

Among 898 PD patients, 677 episodes of peritonitis occurred in 344 patients. Over 10 years, the proportion of gram-negative bacterial peritonitis increased from 0% to 26.15% (p = .045). E. coli was the leading cause (38.51%) of the 148 cases of gram-negative bacterial peritonitis. The increase of E. coli peritonitis between the first 5 and the last 5 years was obvious (20.45% vs. 46.15%). The antimicrobial sensitivity of gram-negative organisms to cefotaxime decreased from 71.43% to 55.84% (p = .017). In the gram-negative group, the effluent white cell count (WCC) on the first day was larger (OR: 1.374;95%CI: 1.248–1.563; p < .001), the time required for the WCC to normalize was longer (OR: 1.100;95%CI: 1.037–1.189; p = .003), and the level of C-reactive protein (CRP) was higher (OR: 1.038;95%CI: 1.026–1.042; p < .001) than those in the gram-positive group. The complete cure rate and treatment failure rate of gram-negative bacteria peritonitis were 87.8% and 12.2% respectively.

Conclusions

Over 10 years, the proportion of gram-negative bacterial peritonitis increased, with E. coli epidermidis being the most common pathogen. More effluent WCC on the first day, longer time required for the WCC to normalize, and higher level of CRP are more common for gram-negative bacterial peritonitis. Prognosis of gram-negative bacterial peritonitis is worse.

Pharmacokinetics of Intraperitoneal Vancomycin and Amikacin in Automated Peritoneal Dialysis Patients With Peritonitis

Objective: The study aimed to evaluate the vancomycin and amikacin concentrations in serum and dialysate for automatic peritoneal dialysis (APD) patients.

Methods: A total of 558 serum and dialysate samples of 12 episodes of gram-positive and 18 episodes of gram-negative peritonitis were included to investigate the relationship between vancomycin and amikacin concentrations in serum and dialysate on the first and third days of treatment. Samples were analysed 30, 120 min, and 48 h after intraperitoneal administration of vancomycin in peritonitis caused by gram-positive agents and 30, 120 min, and 24 h after intraperitoneal administration of amikacin in peritonitis caused by gram-negative agents. Vancomycin was administered every 72 h and amikacin once a day. The target therapeutic concentration of amikacin was 25–35 mg/l at the peak moment and 4–8 mg/l at the trough moment; and after 48 h for vancomycin, 15–20 mg/l at the trough moment.

Results: For peritonitis caused by gram-negative agents, at the peak moment, therapeutic levels of amikacin were reached in dialysate in 80.7% of patients with evolution to cure and in 50% of patients evaluated as non-cure (p = 0.05). At the trough moment, only 38% were in therapeutic concentrations in the dialysate in the cure group and 42.8% in the non-cure group (p = 1). Peak plasma concentrations were subtherapeutic in 98.4% of the samples in the cure group and in 100% of the non-cure group. At the trough moment, therapeutic concentrations were present in 74.4% of the cure group and 71.4% of the non-cure group (p = 1). Regarding vancomycin and among gram-positive agents, therapeutic levels were reached at the peak moment in 94% of the cure group and 6% of the non-cure group (p = 0.007). After 48 h, 56.8% of the cure group had a therapeutic serum concentration whereas for the non-cure group it was only 33.3% (p = 0.39).

Conclusion: Despite a small sample size, we demonstrated peak dialysate amikacin level and peak serum vancomycin level correlates well with Gram-negative and Gram positve peritonitis cure, respectively. It is suggested to study the antibiotics pharmacodynamics for a better understanding of therapeutic success in a larger sample.

Time until treatment initiation is associated with catheter survival in peritoneal dialysis-related peritonitis

For peritonitis, a serious complication of peritoneal dialysis (PD), we investigated the relation between duration from the sign (PD effluent abnormalities) to treatment with appropriate antibiotics (ST time) and catheter removal. For 62 PD hospital patients, data of PD-related peritonitis (n = 109) were collected retrospectively. We examined ST time and PD catheter removal times using univariate and multivariate analyses. The catheter removal rate in the delayed ST time group (≥ 24 h) was higher than that in early ST time group (< 24 h) (38 vs. 16%, p = 0.02). Concomitant tunnel infection and delayed ST time were associated with catheter removal (OR [95% CI] 32.3 [3.15–329] and 3.52 [1.11–11.1]). Rates of catheter removal and re-development of peritonitis within 1 month after starting treatment were higher in the delayed ST time group (p = 0.02). PD duration at peritonitis and the first peritonitis episode were associated with delayed ST time (1.02 [1.00–1.04] and 3.42 [1.09–10.7]). Significant association was found between PD catheter removal and the start of treatment more than 24 h after appearance of abnormal effluent. Education for patients about prompt visitation at the onset of peritonitis with long PD duration might improve outcomes.

Novel Predictors and Risk Score of Treatment Failure in Peritoneal Dialysis-Related Peritonitis

Objective: Peritonitis is a severe complication in peritoneal dialysis (PD). This study was performed to identify predictors and establish a risk score for treatment failure in peritonitis patients.

Methods: A single-center, retrospective observational study was conducted. The basic demographic characteristics, clinical and laboratory data of all patients with peritonitis during the study period were documented and analyzed. Multivariate logistic regression was applied to examine independent predictors of treatment failure, and a risk prediction score was established.

Results: Three hundred fourteen episodes experienced by 241 patients were included in the final analysis. Logistic regression analysis indicated that PD duration (OR 1.017; P 0.005), fibrinogen (OR 1.327; P 0.021), high-density lipoprotein (OR 0.443; P 0.032), fungal infection (OR 63.413; P < 0.001), intestinal obstruction (OR 5.186, P 0.007), and diabetes mellitus (OR 2.451; P 0.018), hemodialysis history (OR 2.804, P 0.006) were independent predictors of treatment failure. The risk prediction score system showed a good calibration (P > 0.05) and discrimination (AUROC 0.80, P < 0.001).

Conclusions: Fibrinogen, PD duration, fungal infection, hemodialysis history, concurrent intestinal obstruction, or diabetes mellitus were independent risk factors for a poor peritonitis outcome, while the high-density lipoprotein was a protective factor. This novel risk prediction score system may be used to predict a high risk of treatment failure effectively.

Successful treatment of Serratia Marcescens peritonitis in a patient receiving peritoneal dialysis

An old man receiving peritoneal dialysis was diagnosed with Serratia marcescens peritonitis, a rare case with poor prognosis. Powerful antibiotics based on culture results and enough duration cured the case successfully despite its high virulence.

Exit site infection and peritonitis due to Serratia species in patients receiving peritoneal dialysis: Epidemiology and clinical outcomes

AIM

To study the epidemiology and clinical outcomes of catheter-related infections of Serratia species in peritoneal dialysis (PD) patients.

METHODS

We retrospectively reviewed the patient characteristics, antibiotics susceptibility/resistance patterns and treatment outcomes of exit site infection (ESI) and peritonitis due to Serratia in PD patients during the period of 2004 to 2017.

RESULTS

One hundred and sixty-one patients had Serratia ESI, of which 10 (6.2%) progressed to tunnel tract involvement and 11 (6.8%) developed PD peritonitis. Nineteen (11.8%) patients with Serratia ESI failed to respond to medical treatment and required catheter removal. Fifty-six (34.8%) patients had repeat Serratia ESI, which occurred at 12.9 ± 13.6 months after the previous episode. Twenty-two patients had Serratia peritonitis, which accounted for 1% of peritonitis during the study period. Ten (45.5%) patients responded to medical treatment while 12 (54.5%) patients required catheter removal. Nine patients (36.4%) failed to resume PD and were converted to long-term haemodialysis. Two patients had repeat peritonitis at 2 months and 3 years, respectively, after the initial episode. Serratia species in PD patients showed high rates of resistance to ampicillin, and first- and second-generation cephalosporins, but were generally susceptible to aminoglycosides, carboxy-/ureido-penicillins and carbapenems.

CONCLUSION

Our results suggest that Serratia ESI show low risk of progression to peritonitis and favourable response to medical therapy, while Serratia peritonitis was associated with high rates of catheter removal and peritoneal failure.

Nontuberculous mycobacteria infections of peritoneal dialysis patients: A multicenter study

OBJECTIVES

Nontuberculous mycobacteria (NTM) infections pose a diagnostic challenge in peritoneal dialysis (PD) patients. In this study, we sought to identify findings that are suggestive of NTM infection in PD adult patients.

METHODS

All patients with NTM exit-site infection (ESI) with/without tunnel infection and peritonitis identified during the last decade in eight medical centers in Israel were included. Clinical, microbiological, and outcome data were collected and analyzed.

RESULTS

Thirty patients were identified; 16 had ESI (53%) and 14 had peritonitis (47%). Median age was 65 years (interquartile range 52-76). Abdominal pain and cloudy PD fluid were reported in all patients with peritonitis, whereas exit-site discharge and granulation tissue were common in patients with ESI. Fourteen patients (47%) had negative cultures prior NTM diagnosis, and isolation of diphtheroids or Corynebacterium spp. was reported in 9 of 30 patients (30%). Antimicrobial treatment prior to diagnosis was documented in 13 of 30 patients (43%). Delayed diagnosis was frequent. Treatment regimens and duration of therapy varied widely. In 26 of 30 (87%) patients, catheter was removed and 19 of 30 patients (63%) required permanent transition to hemodialysis. Two patients with peritonitis (2 of 14, 14%) and seven with ESI (7 of 16, 44%) were eligible for continuation of PD.

CONCLUSIONS

Culture negative peritonitis, isolation of diphtheroids or Corynebacterium spp., previous exposure to antibiotics, and/or a refractory infection should all prompt consideration of PD-related NTM infection and timely workup. Catheter removal is recommended aside prolonged antimicrobial therapy. In select patients with ESI, continuation of PD may be feasible.

Peritonitis-Related Mortality in Patients Undergoing Chronic Peritoneal Dialysis

Peritonitis is a well-known cause of mortality in peritoneal dialysis (PD) patients. We carried out a retrospective study to disclose the clinical spectrum and risk profile of peritonitis-related mortality. We analyzed 693 episodes of infectious peritonitis suffered by 565 patients (follow-up 1149 patient-years). Death was the final outcome in 41 cases (5.9% of episodes), peritonitis being directly implicated in 15.2% of the global mortality and 68.5% of the infectious mortality observed. In 41.5% of patients with peritonitis-related mortality, the immediate cause of death was a cardiovascular event. Highest mortality rates corresponded to fungal (27.5%), enteric (19.3%), and Staphylococcus aureus (15.2%) peritonitis. Multivariate analysis disclosed that the baseline risk of peritonitis-related mortality was significantly higher in female [relative risk (RR) 2.13, 95% confidence interval (CI) 1.24 – 4.09, p = 0.02], older (RR 1.10/year, CI 1.06 – 1.14, p < 0.0005), and malnourished patients (RR 2.51, CI 1.21 – 5.23, p = 0.01) with high serum C-reactive protein (s-CRP) levels (RR 4.04, CI 1.45 – 11.32, p = 0.008) and a low glomerular filtration rate (RR 0.75 per mL/minute, CI 0.64 – 0.87, p < 0.0005). Analysis of risk after a single episode of peritonitis and/or subanalysis restricted to peritonitis caused by more aggressive micro-organisms disclosed that overall comorbidity [odds ratio (OR) 1.21, CI 1.05 – 1.71, p = 0.005], depression (OR 2.35, CI 1.14 – 4.84, p = 0.02), and time on PD at the time of the event (OR 1.02/month, CI 1.00 – 1.03, p = 0.02) were other predictors of mortality.

In summary, the etiologic agent is a definite marker of peritonitis-related mortality but gender, age, residual renal function, inflammation (s-CRP), malnutrition, and depression are other significant correlates of this outcome. Most of these risk factors are common to cardiovascular and peritonitis-related mortality, which may explain the high incidence of cardiovascular event as the immediate cause of death in patients with peritonitis-related mortality.

A Quarter of a Century of Adult Peritoneal Dialysis-Related Peritonitis at an Australian Medical Center

Background

Peritonitis remains one of the major complications of peritoneal dialysis (PD) and results in reduced technique survival and increased patient morbidity and mortality.

Methods

We prospectively recorded comprehensive data on all episodes of PD peritonitis over a 25-year period, including organisms isolated and antibiotic sensitivities. Data on 1588 PD patient-years with 2073 episodes of peritonitis were analyzed; 2089 organisms were isolated in 608 patients. Peritoneal dialysis technique and patient survival were also recorded.

Results

There was a significant decline over the years in the incidence of peritonitis, from 6.5 to 0.35 episodes/patient-year, with the decline in the post twin-bag era from 2.3 to 0.47 ( p < 0.001) due primarily to a decrease in gram-positive organisms. The most common isolates (68.9%) were gram-positive organisms; gram-negative organisms comprised 26.8% and fungi 4.1%. Coagulase-negative staphylococci were the most common pathogen isolated (35.3%). Culture-negative peritonitis was seen in 13.4% of episodes.

Conclusion

This is the largest series of PD peritonitis reported, demonstrating a dramatic reduction over a 25-year period and also detailing the changing trends of organisms isolated in association with improved technique and patient survival. Although rates have improved, peritonitis remains a major complication and further research needs to be done to improve both PD technique and patient survival.

Predictors of Survival and Technique Success after Reinsertion of Peritoneal Dialysis Catheter following Severe Peritonitis

Background

Peritonitis remains the most important complication of peritoneal dialysis (PD). The success rate of restarting PD after severe peritonitis (peritonitis unresolved despite treatment with appropriate antibiotics for 3 days, or fungal or pseudomonas infections) is unclear. We wished to determine PD technique survival and overall mortality when PD is offered to these patients and to identify predictors of successful reinitiation.

Method

We conducted a retrospective single-center study of 556 patients undergoing PD between January 2000 and December 2001. We collected demographic information from the 106 patients who had their PD catheter removed for peritonitis, details about their dialysis history and peritonitis, and whether they successfully restarted PD and if not, the reason.

Results

We divided patients into groups as follows: group 1 ( n = 42) underwent catheter reinsertion, group 2 ( n = 16) had no medical contraindication to restarting PD but the patients elected to remain on hemodialysis, group 3 ( n = 35) were deemed medically unsuitable to return to PD, and group 4 ( n = 13) were those that died within 4 weeks of presenting with peritonitis. If there were no medical contraindications, Indo-Asians were more likely to retry PD. In group 1, after a mean follow-up of 20 ± 7.3 months, 23 of 42 patients restarted PD successfully. Technique survival for group 1 as a whole was 69% at 3 months and 55% at the end of follow-up. Patients of greater dialysis vintage were more likely to develop PD technique failure after restarting. Of those judged suitable for PD, there was no statistically significant difference in the mortality of patients who wished to either restart PD or remain on hemodialysis (group 1 vs group 2). Significant numbers of patients returned successfully to PD after pseudomonas and fungal peritonitis.

Conclusion

Restarting PD after severe peritonitis was possible and safe. Ethnicity was an important predictor for wanting to retry PD, but not for technique failure: given the choice, Indo-Asians preferred PD and had a higher failure rate after restarting, but this did not reach statistical significance. Only dialysis vintage predicted technique failure. We conclude that, after severe peritonitis, patients should be given the choice to return to PD but risk stratification based on dialysis vintage is important. Patient retraining and creating a backup arteriovenous fistula might minimize morbidity in these high-risk patients.

Changes in Causative Organisms and Their Antimicrobial Susceptibilities in Capd Peritonitis: A Single Center's Experience over one Decade

Background

In recent years, the rate of peritonitis during continuous ambulatory peritoneal dialysis (CAPD) has been significantly reduced. However, peritonitis remains a major complication of CAPD, accounting for considerable mortality and hospitalization among CAPD patients.

Objective

To generate a “center tailored” treatment protocol for CAPD peritonitis by examining the changes of causative organisms and their susceptibilities to antimicrobial agents over the past 10 years.

Method

Retrospective review of the medical records of 1015 CAPD patients (1108 episodes of peritonitis) who were followed up from 1992 through 2001.

Results

The overall incidence of peritonitis was 0.40 episodes/patient-year. The annual rate of peritonitis and the incidence of peritonitis caused by a single gram-positive organism were significantly higher in 1992 and 1993 compared with those in the rest of the years ( p < 0.05). The incidence of peritonitis due to coagulase-negative staphylococcus (CoNS) decreased significantly over time, whereas there was no significant change in the incidence of Staphylococcus aureus (SA)-induced peritonitis. Among CoNS, resistance to methicillin increased from 18.4% in 1992 – 1993 to 41.7% in 2000 – 2001 ( p < 0.05). In contrast, the incidence of methicillin-resistant SA was not different according to the calendar year. Catheter removal rates were significantly higher in peritonitis due to a single gram-negative organism (16.6%) compared with gram-positive peritonitis (4.8%, p < 0.005). The mortality associated with peritonitis was also higher in gram-negative (3.7%) compared with gram-positive peritonitis (1.4%), but there was no statistical significance. Among single gram-positive organism-induced peritonitis, catheter removal rates were significantly higher in SA (9.3%) than those in CoNS (2.9%, p < 0.01) and other gram-positive organisms (2.9%, p < 0.05). In peritonitis caused by CoNS, the methicillin-resistant group showed significantly higher removal rates than the methicillin-susceptible group (8.2% vs 1.0%, p < 0.01).

Conclusion

The incidence of peritonitis for 2001 decreased to less than half that for 1992, due mainly to a significant decrease in CoNS-induced peritonitis, whereas the proportions of peritonitis due to a single gram-negative organism and methicillin-resistant CoNS increased. These findings suggest that it is necessary to prepare new center-based guidelines for the initial empirical treatment of CAPD peritonitis.

Vancomycin and Ciprofloxacin: Systemic Antibiotic Administration for Peritoneal Dialysis-Associated Peritonitis

Objectives

Peritonitis due to peritoneal dialysis (PD) is best treated empirically while waiting for the results of the dialysate culture. Thus, antibiotic therapy must cover both gram-positive and gram-negative micro-organisms. First, over a period of 9 years in a multicenter study we evaluated the efficiency of a vancomycin and ciprofloxacin combination given as the first-line treatment protocol for PD peritonitis. Second, we evaluated whether a systemic route of administration of the antibiotics could be an interesting alternative to the usual cumbersome intraperitoneal drug administration.

Methods

Vancomycin 15 mg/kg body weight, intravenous, and oral ciprofloxacin 250 mg two times per day (500 mg twice per day if residual creatinine clearance was above 3 mL/minute) were prescribed at diagnosis of peritonitis. Vancomycin injections were repeated (when blood trough level was expected to be below 12 μg/mL) in cases of gram-positive organisms for a total duration of 3 weeks. Ciprofloxacin was given for a total of 3 weeks in cases of gram-negative and a total of 10 days for susceptible gram-positive infections.

Results

A total of 129 episodes of peritonitis occurred; 28 of them were not included in the study because of protocol violation ( n = 15) or fungal ( n = 7) or fecal ( n = 6) peritonitis, leaving 101 peritonitis episodes for analysis. 52 (51.5%) gram-positive and 28 (27.7%) gram-negative organisms were grown; 38 gram-positive organisms were coagulase-negative staphylococci. No organism was identified in 8 peritonitis episodes, whereas 13 peritonitis episodes were caused by more than 1 organism. 35% of the coagulase-negative staphylococci were resistant to first-generation cephalosporin and methicillin, whereas all were susceptible to vancomycin. For gram-negative bacilli, the susceptibility rate was 96% and 95% for ciprofloxacin and ceftazidime respectively. The overall treatment success rate was 77.2% (78 of the 101 peritonitis episodes): 61.4% at first intention and 15.8% after optimization of the antibiotic therapy (second intention). The protocol failed in 22.8% of the peritonitis episodes. Hospitalization was required in 52% of the peritonitis episodes; average hospitalization was 11 (range 1 – 45) days.

Conclusion

Systemic vancomycin and ciprofloxacin administration is a simple and efficient first-line protocol antibiotic therapy for PD peritonitis. In our opinion, vancomycin should still be used for gram-positive infections because of its high susceptibility rate compared with first-generation cephalosporins, providing a close monitoring of the local epidemiology. Oral ciprofloxacin provides satisfactory results in gram-negative infections, comparable to those obtained with intraperitoneal ceftazidime or aminoglycosides.

Risk Factors and Outcomes of Extended-Spectrum Beta-Lactamase-Producing E. Coli Peritonitis in Capd Patients

Objective

To determine the risk factors and outcomes of peritonitis caused by extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli in continuous ambulatory peritoneal dialysis (CAPD).

Patients and Methods

Episodes of E. coli CAPD peritonitis in our unit from October 1994 to August 2003 were reviewed. Demographic data, underlying medical conditions, recent use of gastric acid inhibitors (including H2 antagonist and proton pump inhibitor), recent antibiotic therapy, antibiotic regimen for peritonitis episodes, sensitivity test results of the E. coli isolated, and clinical outcomes were examined.

Results

Over a 10-year study period, 88 episodes of E. coli peritonitis were recorded; 11 of the 88 cases were caused by ESBL-producing E. coli. Recent use of cephalosporins and gastric acid inhibitor were associated with the development of ESBL-producing E. coli peritonitis. Compared with non-ESBL-producing E. coli peritonitis, more cases in the ESBL-producing E. coli group developed treatment failure (45.5% vs 13.0%, p = 0.02) and died of sepsis (27.3% vs 3.9%, p = 0.02). Peritoneal failure rate was higher in the ESBL-producing E. coli group, although the difference was not statistically significant (18.2% vs 3.9%, p = 0.12).

Conclusion

Peritonitis caused by ESBL-producing E. coli is associated with worse clinical outcomes. The use of cephalosporins and gastric acid inhibitors may contribute to its development. Further studies are warranted to investigate and determine the predisposing factors for ESBL-producing E. coli peritonitis.

Discordant PD Catheter and Effluent Culture Results. The Limited Clinical Relevance of Culturing PD Catheters

Objectives

To determine if discordance in culture results between the effluent and the tip of the peritoneal catheter had an effect on outcome in patients whose peritoneal dialysis (PD) catheter was removed mostly for nonresolving peritonitis. Reasons for and outcomes of PD catheter removal were also analyzed.

Methods

We retrospectively reviewed the charts of all PD patients with recent peritonitis for which the PD catheter was removed between 1 January 2003 and 30 April 2009. Data including basic demographics, the organism isolated from effluent and from the PD catheter, reason for catheter removal, duration of hospitalization, and development of intra-abdominal collection were extracted as well as mortality within 8 weeks post removal and return to PD after catheter removal.

Results

Fungal peritonitis was the most common reason for PD catheter removal. 20% of the patients developed an intra-abdominal collection. Mortality related to PD catheter removal was low (3/53; 5.6%). The patients ( n =53) were divided into 3 groups: group 1 ( n = 20) had the same culture result of effluent and catheter tip; group 2 ( n = 19) had a negative culture of the catheter tip; and group 3 ( n = 14) had different organism(s) growing from effluent and catheter tip. We found no remarkable differences in duration of PD, catheter age, peritonitis rate, or mortality. Patients in group 1 had significantly more fungal peritonitis than the other 2 groups. In only 4 of the 53 patients (7.5%), the anti-infectious management was changed according to the catheter culture result.

Conclusions

Discordant results between catheter tip culture and effluent culture did not have a significant impact on patient outcome. Sending PD catheters for culture has limited clinical importance.

Continuous ambulatory peritoneal dialysis peritonitis: Microbiology and outcomes

Context

Continuous ambulatory peritoneal dialysis (CAPD) is now a preferred mode of the treatment in patients with end-stage renal disease, but peritonitis remains to be a shortcoming of CAPD. High-culture negativity, emerging drug resistance and peritoneal dialysis (PD)-related morbidity and mortality have been a challenge to tackle.

Aims

The present study was taken up to compare the the various culture methods and to identify the spectrum of organisms causing CAPD peritonitis and their outcome.

Settings and Design

A prospective, observational, cross-sectional study was conducted at a tertiary care teaching hospital in Hyderabad over a period of 1 year.

Subjects and Methods

Dialysate fluid from 100 episodes of clinically suspected peritonitis in 75 patients was processed by conventional centrifuging, water lysis, direct inoculation and addition of centrifuged pellet into brain-heart infusion broth and by automated blood culture system. Identification and antibiotic susceptibility of organisms was done, and the outcome of PD-related peritonitis was analysed.

Statistical Analysis Used

The categorical data and continuous data were analysed using the Chi-square test and Student's t-test, respectively. P < 0.05 was considered statistically significant.

Results

Of the 100 PD fluids, 87 were culture positive. Automated blood culture systems detected 87 episodes, whereas conventional centrifuge method detected only 53 episodes (P = 0.00001). Peritonitis due to Gram-negative organisms (62.3%) was higher than that of Gram-positive peritonitis (31.1%) and fungi (6.4%). Nineteen per cent episodes were constituted by relapse (9), refractory (4), recurrent (4) and repeat (2) peritonitis. Outcomes were analysed as recovery (77%), catheter removal (15%) and death (2.6%).

Conclusions

Direct inoculation of peritoneal fluid into automated blood culture bottles increases the positivity rate and also aids in the early detection of CAPD peritonitis, helping reduce morbidity and mortality of PD patients.

First report of peritonitis caused by the vancomycin-resistant coccus Pediococcus pentosaceus in a patient on continuous ambulatory peritoneal dialysis

Introduction

Worldwide, about one-tenth of end-stage renal disease (ESRD) patients are on peritoneal dialysis (PD). Peritonitis is a major cause of PD failure and change of therapy to haemodialysis. An update on peritoneal dialysis-related infections has recommended the use of a first generation cephalosporin or vancomycin as an empirical therapy for Gram-positive organisms. Pediococcus spp. is a Gram-positive environmental cocci that have been increasingly reported from various nosocomial infections but very rarely from peritoneal dialysis infections. It is intrinsically resistant to Vancomycin but sensitive to ampicillin. So, diagnosis of this bacteria is important if isolated from PD infections.

Case presentation.

An elderly female patient of ESRD on continuous ambulatory peritoneal dialysis (CAPD) was admitted with complaints of high fever and cloudy PD effluent for 2 days. She was started with vancomycin and imipenem empirically but did not improve even after 4 days. Pus cells were seen when PD fluid was examined microscopically. BACTEC culture of PD fluid isolated growth of Gram-positive cocci, which was confirmed as Pediococcus pentosaceus. It was resistant to vancomycin. The antibiotic of the patient was changed to ciprofloxacin IV. The patient responded in 2 days and was discharged after 7 days.

Conclusion

This is the first case report of Pediococcus pentosaceus peritonitis in an ESRD patient on CAPD. Accurate diagnosis and antibiotic sensitivity test of the bacteria is important especially if isolated in critical patients as it is intrinsically resistant to vancomycin.

Peritoneal Dialysis Access Associated Infections

Infection is a significant driver of morbidity and mortality in patients with end-stage renal disease undergoing maintenance dialysis. In the United States, septicemia and other infections account for 8% deaths in patients undergoing dialysis. In patients undergoing peritoneal dialysis (PD), PD-related peritonitis remains the most frequent treatment-related infection and is the greatest contributor to infection-related morbidity, including risk for hospitalization, and temporary or permanent transfer to hemodialysis. In the 4 decades since the introduction of ambulatory PD in clinical practice, a large number of treatment innovations have been shown to be effective in reducing the risk for exit site infection and PD-related peritonitis. Notwithstanding the evidence for efficacy of these innovations and the numerous adverse health consequences with PD-related peritonitis, the uptake of these interventions in clinical practice around the world remains inconsistent. This article reviews current knowledge with regards to prevention of PD-associated infections, and the diagnosis and management of exit site infections and peritonitis.

Steady-State Pharmacokinetics of Oral Ciprofloxacin in Continuous Cycling Peritoneal Dialysis Patients: Brief Report

Steady-state pharmacokinetics of oral ciprofloxacin in 3 continuous cycling peritoneal dialysis (CCPD) outpatients given ciprofloxacin 750 mg b.i.d. for 5 doses was determined. Mean steady-state maximum serum concentration and half-life were 4.4 ± 1.5 mg/L and 10.3 ± 2.6 hours, respectively. Mean maximum dialysate concentration in the daytime long dwell and overnight continuous cycling dwell were 7.4 ± 1.2 mg/L and 3.3 ± 1.2 mg/L, respectively. Oral ciprofloxacin 750 mg b.i.d. may be reasonable for bloodstream and peritoneal infections caused by susceptible bacteria in CCPD patients.

A Clinical Risk Prediction Tool for Peritonitis-Associated Treatment Failure in Peritoneal Dialysis Patients

A tool to predict peritonitis-associated treatment failure among peritoneal dialysis (PD) patients has not yet been established. We conducted a multicentre, retrospective cohort study among 1,025 PD patients between 2006 and 2016 in Thailand to develop and internally validate such a tool. Treatment failure was defined as either a requirement for catheter removal, a switch to haemodialysis, or peritonitis-associated mortality. Prediction model performances were analysed using discrimination (C-statistics) and calibration (Hosmer-Lemeshow test) tests. Predictors were weighted to calculate a risk score. In total, 435 patients with 855 episodes of peritonitis were identified; 215 (25.2%) episodes resulted in treatment failure. A total risk score of 11.5 was developed including, diabetes, systolic blood pressure <90 mmHg, and dialysate leukocyte count >1,000/mm³ and >100/mm³ on days 3-4 and day 5, respectively. The discrimination (C-statistic = 0.92; 95%CI, 0.89-0.94) and calibration (P > 0.05) indicated an excellent performance. No significant difference was observed in the internal validation cohort. The rate of treatment failure in the different groups was 3.0% (low-risk, <1.5 points), 54.4% (moderate-risk, 1.5-9 points), and 89.5% (high-risk, >9 points). A simplified risk-scoring scheme to predict treatment failure may be useful for clinical decision making regarding PD patients with peritonitis. External validation studies are needed.

The impact of peritoneal dialysis-related peritonitis on mortality in peritoneal dialysis patients

BACKGROUND

Results concerning the association between peritoneal dialysis-related peritonitis and mortality in peritoneal dialysis patients are inconclusive, with one potential reason being that the time-dependent effect of peritonitis has rarely been considered in previous studies. This study aimed to evaluate whether peritonitis has a negative impact on mortality in a large cohort of peritoneal dialysis patients. We also assessed the changing impact of peritonitis on patient mortality with respect to duration of follow-up.

METHODS

This retrospective cohort study included incident patients who started peritoneal dialysis from 1 January 2006 to 31 December 2011. Episodes of peritonitis were recorded at the time of onset, and peritonitis was parameterized as a time-dependent variable for analysis. We used the Cox regression model to assess whether peritonitis has a negative impact on mortality.

RESULTS

A total of 1321 patients were included. The mean age was 48.1 ± 15.3 years, 41.3% were female, and 23.5% with diabetes mellitus. The median (interquartile) follow-up time was 34 (21-48) months. After adjusting for confounders, peritonitis was independently associated with 95% increased risk of all-cause mortality (hazard ratio, 1.95; 95% confidence interval: 1.46-2.60), 90% increased risk of cardiovascular mortality (hazard ratio, 1.90; 95% confidence interval: 1.28-2.81) and near 4-fold increased risk of infection-related mortality (hazard ratio, 4.94; 95% confidence interval: 2.47-9.86). Further analyses showed that peritonitis was not significantly associated with mortality within 2 years of peritoneal dialysis initiation, but strongly influenced mortality in patients dialysed longer than 2 years.

CONCLUSIONS

Peritonitis was independently associated with higher risk of all-cause, cardiovascular and infection-related mortality in peritoneal dialysis patients, and its impact on mortality was more significant in patients with longer peritoneal dialysis duration.

Research on Handwashing Techniques of Peritoneal Dialysis Patients From Yiwu, Southeast China

The aim of the present study was to evaluate handwashing technique, bacteriology, and factors influencing handwashing technique of 86 stable chronic peritoneal dialysis (PD) patients from Yiwu City in Southeast China. Based on the "Hygienic standard for disinfection in the hospital", we also performed sampling for bacteriology from PD operators after they washed their hands. We compared their clinical features including the pathogenic bacteria of their previous peritonitis episodes and their handwashing evaluation results according to their bacteriologic sampling results. 65% of patients turned off the tap by bare hand, and 74% did not follow the six-step handwashing method. Dialysis duration longer than 6 months (P = 0.04) and lower income (P = 0.05) were independent risk factors for higher handwashing error scores. The overall rate of appropriate handwashing, according to the "hygienic standard for disinfection in the hospital" was 26%. The bacteriologic sampling results showed that the most common pathogenic bacterium was Staphylococcus aureus (92%). PD operators whose hand bacteria culture was qualified contained a lower proportion of participants with advanced age (P = 0.07). Patients with repeated peritonitis occurrence had a significantly higher score on handwashing error (P < 0.01) and were more likely to develop Staphylococcus infection. We found that in Yiwu city patients on dialysis for more than 6 months, were of low income and had multiple prior episodes of PD peritonitis had poor handwashing compliance. Elderly patients had higher rates of positive bacterial culture (Staphylococcus) from their hands.

Dialysate White Blood Cell Change after Initial Antibiotic Treatment Represented the Patterns of Response in Peritoneal Dialysis-Related Peritonitis

Background. Patients with peritoneal dialysis-related peritonitis usually have different responses to initial antibiotic treatment. This study aimed to explore the patterns of response by using the changes of dialysate white blood cell count on the first five days of the initial antibiotic treatment. Materials and Methods. A retrospective cohort study was conducted. All peritoneal dialysis-related peritonitis episodes from January 2014 to December 2015 were reviewed. We categorized the patterns of antibiotic response into 3 groups: early response, delayed response, and failure group. The changes of dialysate white blood cell count for each pattern were determined by multilevel regression analysis. Results. There were 644 episodes in 455 patients: 378 (58.7%) of early response, 122 (18.9%) of delayed response, and 144 (22.3%) of failure episodes. The patterns of early, delayed, and failure groups were represented by the average rate reduction per day of dialysate WBC of 68.4%, 34.0%, and 14.2%, respectively (p value < 0.001 for all comparisons). Conclusion. Three patterns, which were categorized by types of responses, have variable rates of WBC declining. Clinicians should focus on the delayed response and failure patterns in order to make a decision whether to continue medical therapies or to aggressively remove the peritoneal catheter.

Risk factors for drainage-requiring ascites after refractory peritonitis in peritoneal dialysis patients

PURPOSE

Refractory peritonitis remains a thorny issue for patients with chronic peritoneal dialysis (PD). Shortly after catheter removal, some patients develop persistent peritoneal inflammation and ascites formation, which require percutaneous drainage for symptom relief. Our study aimed at finding the risk factors for this kind of event.

METHODS

A total of 47 PD patients complicated with refractory peritonitis who underwent catheter removal between January 2009 and December 2011 were enrolled in this study. Data were compared between patients with and without the development of symptomatic ascites requiring drainage during hospitalization.

RESULTS

Among the 47 refractory peritonitis patients, 15 patients developed symptomatic ascites that needed further drainage shortly after catheter removal during hospitalization. The following factors were associated with an increased risk: longer dialysis duration, higher peritoneal Kt/V urea, and a significant rise in serum C-reactive protein (CRP) level after catheter removal. These patients had a prolonged hospital stay (62 vs 21 days, P < 0.001) and a significantly higher risk of recurrent loculated ascites during subsequent 6 months of follow-up (33.3 vs 6.2 %, P = 0.022) compared with patients who did not develop ascites requiring drainage during hospitalization.

CONCLUSION

A significant portion of patients with refractory PD peritonitis experienced ascites requiring drainage shortly after catheter removal, which led to a prolonged hospitalization. Whether routine drain placement at the time of catheter removal for this high-risk group would be of benefit warrants further prospective studies.

Intraperitoneal meropenem for peritoneal dialysis peritonitis with Serratia marcescens immediately on commencing dialysis

A 67-year-old man developed Serratia marcescens peritonitis within a week of commencing peritoneal dialysis. Dialysate cultures isolated multidrug-resistant S. marcescens, which was treated with intraperitoneal meropenem. This unusual case highlights the problem of multidrug-resistant peritoneal dialysis infections and the potential viability of intraperitoneal meropenem as ambulatory peritonitis therapy.

Patient Survival and Technique Failure in Continuous Ambulatory Peritoneal Dialysis Patients with Prior Stroke

♦

BACKGROUND

To investigate patient survival and technical failure of patients with prior stroke receiving continuous ambulatory peritoneal dialysis (CAPD) in Southern China. ♦

METHODS

This was a retrospective study. All subjects were recruited from the peritoneal dialysis center in The First Affiliated Hospital of Sun Yat-sen University from 1 January 2006 to 31 December 2010. All eligible patients were assigned to stroke group and non-stroke group according to a history of stroke before receiving CAPD. The primary outcomes were all-cause mortality and death-censored technical failure. Cox regression was used to estimate risk factors of all-cause mortality and death-censored technique failure. ♦

RESULTS

Of the 1,068 recruited patients, 75 (7.0%) patients had a previous history of stroke. The all-cause mortality and death-censored technique failure were significantly higher in the stroke group compared with the non-stroke group, respectively (odds ratio [OR] 2.67, 95% confidence interval [CI] 1.59 - 4.46 and OR 2.52, 95% CI 1.19 - 5.34). Older age (changed by 10 years, hazard ratio [HR] 1.90, 95% CI 1.07 - 3.38), lower body mass index (BMI 18.5 - 23.9 vs < 18.5 kg/m(2) reference, HR 0.17, 95% CI 0.05 - 0.55) and time to the first episode of peritonitis (HR 0.93, 95% CI 0.89 - 0.96) were independently associated with increased risk of all-cause mortality in patients with prior stroke. In addition, time to the first episode of peritonitis was associated with decreased risk of death-censored technique failure (HR 0.91, 95% CI 0.84 - 0.99) in those with prior stroke. ♦

CONCLUSIONS

Continuous ambulatory peritoneal dialysis patients with prior stroke had high rates of all-cause mortality and technique failure compared with those without prior stroke. Older age, lower BMI, and time to the first episode of peritonitis were independent risk factors of all-cause mortality in patients with prior stroke.

Exit-Site Dressing and Infection in Peritoneal Dialysis: A Randomized Controlled Pilot Trial

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OBJECTIVE

Peritoneal dialysis (PD)-related infection is a common cause of catheter loss and the main reason for PD drop-out. Exit-site infection (ESI) is a pathway to developing tunnel infection and peritonitis, hence rigorous exit-site care has always been emphasized in PD therapy. The aim of this study was to evaluate the effect of exit-site dressing vs non-dressing on the rate of PD-related infection. ♦

METHODS

A prospective randomized controlled study was conducted in prevalent PD patients at the Hospital Tuanku Jaafar Seremban, Negeri Sembilan, Malaysia, from April 2011 until April 2013. All patients were required to perform daily washing of the exit site with antibacterial soap during a shower. In the dressing group (n = 54), patients were required to clean their exit site using povidone-iodine after drying, followed by topical mupirocin antibiotic application to the exit site. The exit site was then covered with a sterile gauze dressing and the catheter immobilized with tape. In the non-dressing group (n = 54), patients were not required to do any further dressing after drying. They were only required to apply mupirocin cream to the exit site and then left the exit site uncovered. The catheter was immobilized with tape. The primary outcome was ESI. The secondary outcomes were evidence of tunnel infection or peritonitis. ♦

RESULTS

A total of 97 patients completed the study. There were a total of 12 ESI episodes: 4 episodes in 4 patients in the dressing group vs 8 episodes in 4 patients in the non-dressing group. This corresponds to 1 episode per 241.3 patient-months vs 1 episode per 111.1 patient-months in the dressing and non-dressing groups respectively. Median time to first ESI episode was shorter in the non-dressing than in the dressing group, but not significant (p = 0.25). The incidence of gram-positive ESI in both groups was similar. There were no gram-negative ESI in the non-dressing group compared with 2 in the dressing group. The peritonitis rate was 1 per 37.1 patient-month in the dressing group and 1 per 44.4 patient-months in the non-dressing group. Median time to first peritonitis episode was significantly shorter in the dressing group compared to non-dressing (p = 0.03). There was no impact of dressing disruptions in the occurrence of major PD catheter-related infection. ♦

CONCLUSION

Use of a non-dressing technique with only prophylactic topical mupirocin cream application is effective in preventing PD-related infection. The non-dressing technique is more cost-effective and convenient for PD patients, with fewer disposables.

The Effect of Exit-Site Antibacterial Honey Versus Nasal Mupirocin Prophylaxis on the Microbiology and Outcomes of Peritoneal Dialysis-Associated Peritonitis and Exit-Site Infections: A Sub-Study of the Honeypot Trial

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BACKGROUND

The HONEYPOT study recently reported that daily exit-site application of antibacterial honey was not superior to nasal mupirocin prophylaxis for preventing overall peritoneal dialysis (PD)-related infection. This paper reports a secondary outcome analysis of the HONEYPOT study with respect to exit-site infection (ESI) and peritonitis microbiology, infectious hospitalization and technique failure. ♦

METHODS

A total of 371 PD patients were randomized to daily exit-site application of antibacterial honey plus usual exit-site care (N = 186) or intranasal mupirocin prophylaxis (in nasal Staphylococcus aureus carriers only) plus usual exit-site care (control, N = 185). Groups were compared on rates of organism-specific ESI and peritonitis, peritonitis- and infection-associated hospitalization, and technique failure (PD withdrawal). ♦

RESULTS

The mean peritonitis rates in the honey and control groups were 0.41 (95% confidence interval [CI] 0.32 - 0.50) and 0.41 (95% CI 0.33 - 0.49) episodes per patient-year, respectively (incidence rate ratio [IRR] 1.01, 95% CI 0.75 - 1.35). When specific causative organisms were examined, no differences were observed between the groups for gram-positive (IRR 0.99, 95% CI 0.66 - 1.49), gram-negative (IRR 0.71, 95% CI 0.39 - 1.29), culture-negative (IRR 2.01, 95% CI 0.91 - 4.42), or polymicrobial peritonitis (IRR 1.08, 95% CI 0.36 - 3.20). Exit-site infection rates were 0.37 (95% CI 0.28 - 0.45) and 0.33 (95% CI 0.26 - 0.40) episodes per patient-year for the honey and control groups, respectively (IRR 1.12, 95% CI 0.81 - 1.53). No significant differences were observed between the groups for gram-positive (IRR 1.10, 95% CI 0.70 - 1.72), gram-negative (IRR: 0.85, 95% CI 0.46 - 1.58), culture-negative (IRR 1.88, 95% CI 0.67 - 5.29), or polymicrobial ESI (IRR 1.00, 95% CI 0.40 - 2.54). Times to first peritonitis-associated and first infection-associated hospitalization were similar in the honey and control groups. The rates of technique failure (PD withdrawal) due to PD-related infection were not significantly different between the groups. ♦

CONCLUSION

Compared with standard nasal mupirocin prophylaxis, daily topical exit-site application of antibacterial honey resulted in comparable rates of organism-specific peritonitis and ESI, infection-associated hospitalization, and infection-associated technique failure in PD patients.

Hyponatremia is a surrogate marker of poor outcome in peritoneal dialysis-related peritonitis

Background

Hyponatremia is known to be a marker of poor prognosis in many clinical conditions. The association between hyponatremia and clinical outcomes in peritoneal dialysis-related peritonitis (PDRP) has not been studied. We evaluated the association between hyponatremia and clinical parameters of patients with PDRP.

Methods

We conducted a retrospective analysis of medical records of patients with PDRP admitted to a medical center in the period 2004-2011. Patients with serum Na⁺ <130 mEq/L and ≥ 130 mEq/L at admission were divided into hyponatremic and normonatremic groups, respectively. The demographic and laboratory characteristics, pathogens of peritonitis, length of hospital stay and mortality rate were analyzed.

Results

Hyponatremia occurred in 27% (27/99) patients with PDRP. Gram-negative bacilli were the major pathogen responsible for 78% (21/27) PDRP in hyponatremic group while gram-positive cocci were found in 75% (41/55) PDRP in normonatremic groups. There was no significant difference in age, duration of dialysis, PD catheter removal rate and technique failure between two groups. Hyponatremic group had significantly higher serum CRP (p <0.001), lower serum albumin (p < 0.001) and phosphate (p < 0.05). Of note, serum Na⁺ level was positively correlated with serum albumin (p < 0.001), phosphate (p < 0.04) levels, and subjective global assessment (SGA) score (p < 0.001). Moreover, the length of hospital stay was longer and in-hospital mortality rate was higher in hyponatremic group (p < 0.001). Using a multivariable logistic regression, we showed that hyponatremia at admission is an independent predictor of in-hospital mortality (OR 76.89 95% CI 3.39-1741.67, p < 0.05) and long hospital stay (OR 5.37, 95% CI 1.58- 18.19, p < 0.05).

Conclusions

In uremic patients with PDRP, hyponatremia at admission associated with a high frequency of gram negative bacilli infection, low serum albumin and phosphate levels, low SGA score, and poor prognosis with long hospital stay and high mortality rate.

Clinical research in a modern Chinese peritoneal dialysis center

A prerequisite for enhancing the quality of peritoneal dialysis is the continuous review and analysis of clinical data from routine clinical care and research. Here, we describe our strategy (Peking University First Hospital, Beijing, China) to achieve that objective.

Reinitiation of peritoneal dialysis after catheter removal for refractory peritonitis

AIM

A high proportion of patients whose catheters are removed are unable to successfully reinitiate peritoneal dialysis (PD) due to irreversible peritoneal injury or to decisions made by the patient or the nephrologist for different and often empiric reasons. The present study examined the outcomes of patients reinitiated on PD after peritonitis.

METHODS

We reviewed all patients with end-stage renal disease who were initiated on continuous ambulatory peritoneal dialysis at our Institute in south India between 1998 and 2012, identifying those in whom the catheter was removed and the cases where PD was reinitiated, analysing the reasons and outcome. We compared data of patients who could be reinitiated on PD with those who could not be reinitiated and also data of patients who successfully continued PD after reinitiation with those who suffered technique failure.

RESULTS

Peritoneal dialysis was reinitiated in 31 (19.4%) of 159 patients whose catheter was removed owing to refractory peritonitis, including after an episode of Pseudomonas aeruginosa and fungal peritonitis. Some patients had the catheter placed for a third time. No significant difference was found between patients who reinitiated PD vs. did not, or between those who were successful in reinitiating PD vs. unsuccessful.

CONCLUSION

Notwithstanding the small cohort size, the present study demonstrates that reinitiating PD is feasible in a developing country, and also that reinitiation of PD is possible after an episode of P. aeruginosa and fungal peritonitis. However, future studies in a larger patient cohort and assessing dialysis adequacy are required to confirm and extend our findings.

The negative impact of early peritonitis on continuous ambulatory peritoneal dialysis patients

BACKGROUND

Peritonitis rate has been reported to be associated with technique failure and overall mortality in previous literatures. However, information on the impact of the timing of the first peritonitis episode on continuous ambulatory peritoneal dialysis (CAPD) patients is sparse. The aim of this research is to study the influence of time to first peritonitis on clinical outcomes, including technique failure, patient mortality and dropout from peritoneal dialysis (PD).

METHODS

A retrospective observational cohort study was conducted over 10 years at a single PD unit in Taiwan. A total of 124 patients on CAPD with at least one peritonitis episode comprised the study subjects, which were dichotomized by the median of time to first peritonitis into either early peritonitis patients or late peritonitis patients. Cox proportional hazard model was used to analyze the correlation of the timing of first peritonitis with clinical outcomes.

RESULTS

Early peritonitis patients were older, more diabetic and had lower serum levels of creatinine than the late peritonitis patients. Early peritonitis patients were associated with worse technique survival, patient survival and stay on PD than late peritonitis patients, as indicated by Kaplan-Meier analysis (log-rank test, p = 0.04, p < 0.001, p < 0.001, respectively). In the multivariate Cox regression model, early peritonitis was still a significant predictor for technique failure (hazard ratio (HR), 0.54; 95% confidence interval (CI), 0.30 - 0.98), patient mortality (HR, 0.34; 95% CI, 0.13 - 0.92) and dropout from PD (HR, 0.50; 95% CI, 0.30 - 0.82). In continuous analyses, a 1-month increase in the time to the first peritonitis episode was associated with a 2% decreased risk of technique failure (HR, 0.98; 95% CI, 0.97 - 0.99), a 3% decreased risk of patient mortality (HR, 0.97; 95% CI, 0.95 - 0.99), and a 2% decreased risk of dropout from PD (HR, 98%; 95% CI, 0.97 - 0.99). Peritonitis rate was inversely correlated with time to first peritonitis according to the Spearman analysis (r = -0.64, p < 0.001).

CONCLUSIONS

Time to first peritonitis is significantly correlated with clinical outcomes of peritonitis patients with early peritonitis patients having poor prognosis. Patients with shorter time to first peritonitis were prone to having a higher peritonitis rate.

Pathogen-specific local immune fingerprints diagnose bacterial infection in peritoneal dialysis patients

Accurate and timely diagnosis of bacterial infection is crucial for effective and targeted treatment, yet routine microbiological identification is inefficient and often delayed to an extent that makes it clinically unhelpful. The immune system is capable of a rapid, sensitive and specific detection of a broad spectrum of microbes, which has been optimized over millions of years of evolution. A patient's early immune response is therefore likely to provide far better insight into the true nature and severity of microbial infections than conventional tests. To assess the diagnostic potential of pathogen-specific immune responses, we characterized the local responses of 52 adult patients during episodes of acute peritoneal dialysis (PD)-associated peritonitis by multicolor flow cytometry and multiplex ELISA, and defined the immunologic signatures in relation to standard microbiological culture results and to clinical outcomes. We provide evidence that unique local "immune fingerprints" characteristic of individual organisms are evident in PD patients on the day of presentation with acute peritonitis and discriminate between culture-negative, Gram-positive, and Gram-negative episodes of infection. Those humoral and cellular parameters with the most promise for defining disease-specific immune fingerprints include the local levels of IL-1β, IL-10, IL-22, TNF-α, and CXCL10, as well as the frequency of local γδ T cells and the relative proportion of neutrophils and monocytes/macrophages among total peritoneal cells. Our data provide proof of concept for the feasibility of using immune fingerprints to inform the design of point-of-care tests that will allow rapid and accurate infection identification and facilitate targeted antibiotic prescription and improved patient management.