Clinical course of peritonitis due to Pseudomonas species complicating peritoneal dialysis: a review of 104 cases

Clinical practice guideline for the prevention and management of peritoneal dialysis associated infections in children: 2024 update

Infection-related complications remain the most significant cause for morbidity and technique failure in infants, children and adolescents who receive maintenance peritoneal dialysis (PD). The 2024 update of the Clinical Practice Guideline for the Prevention and Management of Peritoneal Dialysis Associated Infection in Children builds upon previous such guidelines published in 2000 and 2012 and provides comprehensive treatment guidance as recommended by an international group of pediatric PD experts based upon a review of published literature and pediatric PD registry data. The workgroup prioritized updating key clinical issues contained in the 2012 guidelines, in addition to addressing additional questions developed using the PICO format. A variety of new guideline statements, highlighted by those pertaining to antibiotic therapy of peritonitis as a result of the evolution of antibiotic susceptibilities, antibiotic stewardship and clinical registry data, as well as new clinical benchmarks, are included. Recommendations for future research designed to fill important knowledge gaps are also provided.

Frequency and prognosis of peritoneal dialysis-associated peritonitis in children

BACKGROUND

Peritonitis is the leading cause of peritoneal dialysis (PD) discontinuation. However, few data concern risk factors of peritonitis development and catheter removal caused by treatment failure in pediatric patients.

METHODS

This single-center, retrospective study analyzed data from pediatric patients who underwent chronic PD between March 2002 and June 2022. The incidence rates of peritonitis by the person-year method were calculated, and they were stratified by patient age groups. Risk factors for peritonitis development and catheter removal were also analyzed by multivariate analysis using logistic regression model.

RESULTS

Ninety patients were enrolled, and 62 peritonitis episodes were observed in 41 (46%) patients. The incidence rate of peritonitis was 0.21 episodes per patient-year, which was the highest in children aged under 2 years old (0.26 episodes per patient-year). Moreover, 44 (71%) cases were successfully cured by antibiotics alone, although 17 (27%) cases required catheter removal, and 4 (6%) cases transitioned to chronic hemodialysis because of peritoneal dysfunction. One patient died. The risk factor for peritonitis development and catheter removal caused by treatment failure was PD insertion at under 2 years old (odds ratio = 2.5; P = 0.04) and Pseudomonas aeruginosa (odds ratio = 11.0; P = 0.04) in the multivariate analysis. P. aeruginosa was also a risk factor for difficulty in re-initiating PD (P = 0.004).

CONCLUSIONS

The incidence rate of peritonitis was the highest in children under 2 years old. P. aeruginosa peritonitis is a risk factor for catheter removal and peritoneal dysfunction.

Best Practice of Peritoneal Dialysis-Associated Gram-Negative Peritonitis in Children: Insights From the International Pediatric Peritoneal Dialysis Network Registry

Introduction

Gram-negative peritonitis (GNP) is associated with significant morbidity in children receiving long-term peritoneal dialysis (PD) and current treatment recommendations are based on limited data.

Methods

Analysis of 379 GNP episodes in 308 children (median age 6.9 years, interquartile range [IQR]: 3.0-13.6) from 45 centers in 28 countries reported to the International Pediatric Peritoneal Dialysis Network registry between 2011 and 2023.

Results

Overall, 74% of episodes responded well to empiric therapy and full functional recovery (FFR) was achieved in 82% of cases. In vitro bacterial susceptibility to empiric antibiotics and lack of severe abdominal pain at onset were associated with a good initial response. Risk factors for failure to achieve FFR included severe abdominal pain at onset and at 60 to 72 hours from treatment initiation (odds ratio [OR]: 3.81, 95% confidence interval [CI]: 2.01-7.2 and OR: 3.94, 95% CI: 1.06-14.67, respectively), Pseudomonas spp. etiology (OR: 1.73, 95% CI: 1.71-4.21]) and in vitro bacterial resistance to empiric antibiotics (OR: 2.40, 95% CI: 1.21-4.79); the risk was lower with the use of monotherapy as definitive treatment (OR: 0.40, 95% CI: 0.21-0.77). Multivariate analysis showed no benefit of dual antibiotic therapy for treatment of Pseudomonas peritonitis after adjustment for age, presenting symptomatology, 60 to 72-hour treatment response, and treatment duration. Monotherapy with cefazolin in susceptible Enterobacterales peritonitis resulted in a similar FFR rate (91% vs. 93%) as treatment with ceftazidime or cefepime monotherapy.

Conclusion

Detailed microbiological assessment, consisting of patient-specific and center-specific antimicrobial susceptibility data, should guide empiric treatment. Treatment "deescalation" with the use of monotherapy and narrow spectrum antibiotics according to susceptibility data is not associated with inferior outcomes and should be advocated in the context of emerging bacterial resistance.

Unusual and complicated peritonitis: Your questions answered

Effective treatment of infections is a growing challenge owing to antimicrobial resistance. Peritoneal dialysis (PD) patients experience more frequent hospitalisations than the general population and have greater exposure to antibiotics, making them particularly vulnerable to this threat. Over the last decade, we have noted a surge in cases of complicated peritoneal dialysis-associated peritonitis (PD peritonitis) caused by antimicrobial-resistant organisms, including extended-spectrum beta-lactamase (ESBL), AmpC beta-lactamase-producing Enterobacterales, Pseudomonas aeruginosa and fungi. Practitioners must be alert to these organisms, seek early recognition of these resistance patterns and make timely adjustments in order to avoid delay in treatment that may increase risk of PD catheter removal and technique failure. We present a case of successful treatment of ESBL peritonitis, highlight its challenges, while providing guidance on management of other unusual and complicated PD peritonitis.

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.

Optimal peritoneal fluid white blood cell count for diagnosis of peritonitis in peritoneal dialysis patients

BACKGROUND

The diagnosis of peritonitis among peritoneal dialysis (PD) patients is based on clinical presentation, dialysis effluent white blood cell (WBC) count, and dialysis effluent culture. Peritoneal fluid WBC count is very important in the initial diagnosis of peritonitis. The purpose of this work was to determine the optimal number of peritoneal WBCs with different clinical presentations at admission to define PD-related peritonitis.

METHODS

Medical records of chronic PD patients who underwent work-up for suspected peritonitis between 2008 and 2019 were reviewed retrospectively. Results of all peritoneal WBC count tests during this period were collected. Clinical manifestations and follow-up analysis of each peritoneal WBC count were performed.

RESULTS

The peritoneal WBC count cutoff of 100/μL recommended by International Society for Peritoneal Dialysis provided specificity of only 35%. Increasing peritoneal WBC count cutoff to 150, 200, and 250/μL provided sensitivity around 98% and gradually increasing specificity. The chi-square automatic interaction detector model of statistical analysis determined that peritoneal WBC count below 230/μL combined with absence of inflammatory markers (fever, increased C-reactive protein) ruled out peritonitis with 99.8% sensitivity. Peritoneal fluid WBC count cutoff of 230/μL provided specificity of 89% and good positive and negative likelihood scores of 8.3 and 0.03, respectively. Peritoneal fluid polymorphonuclear count has lower discriminating ability for peritonitis compared to peritoneal fluid WBC count.

CONCLUSION

Increasing peritoneal fluid WBC count cutoff to 230/μL in suspected PD-related peritonitis could improve specificity without compromising the sensitivity of the test.

ISPD peritonitis guideline recommendations: 2022 update on prevention and treatment

Peritoneal dialysis (PD)-associated peritonitis is a serious complication of PD and prevention and treatment of such is important in reducing patient morbidity and mortality. The ISPD 2022 updated recommendations have revised and clarified definitions for refractory peritonitis, relapsing peritonitis, peritonitis-associated catheter removal, PD-associated haemodialysis transfer, peritonitis-associated death and peritonitis-associated hospitalisation. New peritonitis categories and outcomes including pre-PD peritonitis, enteric peritonitis, catheter-related peritonitis and medical cure are defined. The new targets recommended for overall peritonitis rate should be no more than 0.40 episodes per year at risk and the percentage of patients free of peritonitis per unit time should be targeted at >80% per year. Revised recommendations regarding management of contamination of PD systems, antibiotic prophylaxis for invasive procedures and PD training and reassessment are included. New recommendations regarding management of modifiable peritonitis risk factors like domestic pets, hypokalaemia and histamine-2 receptor antagonists are highlighted. Updated recommendations regarding empirical antibiotic selection and dosage of antibiotics and also treatment of peritonitis due to specific microorganisms are made with new recommendation regarding adjunctive oral N-acetylcysteine therapy for mitigating aminoglycoside ototoxicity. Areas for future research in prevention and treatment of PD-related peritonitis are suggested.

EDTA and Taurolidine Affect Pseudomonas aeruginosa Virulence In Vitro-Impairment of Secretory Profile and Biofilm Production onto Peritoneal Dialysis Catheters

Peritoneal catheter-associated biofilm infection is reported to be the main cause of refractory peritonitis in peritoneal dialysis patients. The application of antimicrobial lock therapy, based on results on central venous catheters, may be a promising option for treatment of biofilm-harboring peritoneal catheters. This study investigated the effects of two lock solutions, EDTA and taurolidine, on an in vitro model of Pseudomonas aeruginosa biofilm-related peritoneal catheter infection. Silicone peritoneal catheters were incubated for 24 h with a bioluminescent strain of P. aeruginosa. Then, serial dilutions of taurolidine and/or EDTA were applied (for 24 h) once or twice onto the contaminated catheters, and P. aeruginosa viability/persistence were evaluated in real time up to 120 h using a Fluoroskan reader. On selected supernatants, high-performance liquid chromatography mass spectrometry (HPLC-MS) analysis was performed to measure the production of autoinducers (AI), phenazines, and pyocyianines. Taurolidine alone or in combination with EDTA caused a significant decrease of bacterial load and biofilm persistence on the contaminated catheters. The treatment did not lead to the sterilization of the devices, yet it resulted in a substantial destructuration of the catheter-associated P. aeruginosa biofilm. HPLC-MS analysis showed that the treatment of biofilm-harboring catheters with taurolidine and EDTA also affected the secretory activity of the pathogen. EDTA and taurolidine affect P. aeruginosa biofilm produced on peritoneal catheters and profoundly compromise the microbial secretory profile. Future studies are needed to establish whether such lock solutions can be used to render peritoneal catheter-related infections more susceptible to antibiotic treatment. IMPORTANCE An in vitro model allows studies on the mechanisms by which the lock solutions exert their antimicrobial effects on catheter-associated biofilm, thus providing a better understanding of the management of devise-associated infections.

Clinical course of peritoneal dialysis-related peritonitis due to non-tuberculosis mycobacterium - A single centre experience spanning 20 years

BACKGROUND

Peritoneal dialysis (PD)-related peritonitis caused by non-tuberculous mycobacteria (NTM) are difficult to diagnose, is associated with significant morbidity and mortality, and clinical course remains unclear. We determined the prevalence and clinical course of peritonitis caused by these organisms through our kidney registry over 20-year period.

METHOD

We reviewed all patients with NTM peritonitis identified in our tertiary centre between July 2000 and July 2020. The demographic characteristics, microbiological and clinical outcomes were examined.

RESULT

Among 27 patients identified, 20 patients presented with abdominal pain and all had cloudy peritoneal fluid. Twenty-one cases had concomitant exit site infection and 14 cases had prior antibiotic use. The majority of the cases are caused by Mycobacterium chelonae (37%) and Mycobacterium fortuitum (29.7%), with most being resistant to fluoroquinolones (59.3%) and cefoxitin (73.1%). They are all sensitive to amikacin otherwise. None of the cases achieve primary response at day 10 and 20 cases resulted in Tenckhoff catheter removal. Only two of them were able to resume PD. Eight patients died in our cohort. The presence of exit site infection, the use of prior antibiotics and topical disinfectants did not associate with a poorer outcome.

CONCLUSION

NTM peritonitis remains difficult to treat and often with a delay in diagnosis. Refractory peritonitis with negative culture and a poor response to standard antibiotics should raise a possibility of NTM infection and prompt catheter removal and an expert with experience treating NTM infections should be consulted.

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.

Peritoneal Dialysis Guidelines 2019 Part 1 (Position paper of the Japanese Society for Dialysis Therapy)

Approximately 10 years have passed since the Peritoneal Dialysis Guidelines were formulated in 2009. Much evidence has been reported during the succeeding years, which were not taken into consideration in the previous guidelines, e.g., the next peritoneal dialysis PD trial of encapsulating peritoneal sclerosis (EPS) in Japan, the significance of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs), the effects of icodextrin solution, new developments in peritoneal pathology, and a new international recommendation on a proposal for exit-site management. It is essential to incorporate these new developments into the new clinical practice guidelines. Meanwhile, the process of creating such guidelines has changed dramatically worldwide and differs from the process of creating what were “clinical practice guides.” For this revision, we not only conducted systematic reviews using global standard methods but also decided to adopt a two-part structure to create a reference tool, which could be used widely by the society’s members attending a variety of patients. Through a working group consensus, it was decided that Part 1 would present conventional descriptions and Part 2 would pose clinical questions (CQs) in a systematic review format. Thus, Part 1 vastly covers PD that would satisfy the requirements of the members of the Japanese Society for Dialysis Therapy (JSDT). This article is the duplicated publication from the Japanese version of the guidelines and has been reproduced with permission from the JSDT.

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.

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.

Gram-Negative Peritonitis—The Achilles Heel of Peritoneal Dialysis?

Peritonitis caused by gram-negative bacteria is a serious complication of peritoneal dialysis. Antibiotic resistance is common, and response to medical treatment is often poor. In the present article, we review recent advances in the understanding of the pathogenesis and treatment of this serious condition.

AABIP Evidence-informed Guidelines and Expert Panel Report for the Management of Indwelling Pleural Catheters

BACKGROUND

While the efficacy of Indwelling pleural catheters for palliation of malignant pleural effusions is supported by relatively robust evidence, there is less clarity surrounding the postinsertion management.

METHODS

The Trustworthy Consensus-Based Statement approach was utilized to develop unbiased, scientifically valid guidance for the management of patients with malignant effusions treated with indwelling pleural catheters. A comprehensive electronic database search of PubMed was performed based on a priori crafted PICO questions (Population/Intervention/Comparator/Outcomes paradigm). Manual searches of the literature were performed to identify additional relevant literature. Dual screenings at the title, abstract, and full-text levels were performed. Identified studies were then assessed for quality based on a combination of validated tools. Appropriateness for data pooling and formation of evidence-based recommendations was assessed using predetermined criteria. All panel members participated in development of the final recommendations utilizing the modified Delphi technique.

RESULTS

A total of 7 studies were identified for formal quality assessment, all of which were deemed to have a high risk of bias. There was insufficient evidence to allow for data pooling and formation of any evidence-based recommendations. Panel consensus resulted in 11 ungraded consensus-based recommendations.

CONCLUSION

This manuscript was developed to provide clinicians with guidance on the management of patients with indwelling pleural catheters placed for palliation of malignant pleural effusions. Through a systematic and rigorous process, management suggestions were developed based on the best available evidence with augmentation by expert opinion when necessary. In addition, these guidelines highlight important gaps in knowledge which require further study.

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.

Influence of Climate on the Incidence of Peritoneal Dialysis-Related Peritonitis

Objective

The use of peritoneal dialysis has expanded in many developing subtropical countries; however, the role of climatic factors in dialysis-related peritonitis has not been studied in detail.

Design

Retrospective study.

Setting

A single regional dialysis unit in a university teaching hospital.

Patients

We reviewed all cases of dialysis-related peritonitis treated in our dialysis unit from January 1995 to December 2001. Information was collected on demographic data, microbiologic etiology, associated catheter exit-site infection, and clinical response.

Results

In 24 059 patient-months of follow-up, 1344 episodes of peritonitis were recorded. There were significantly more peritonitis episodes in July and August [odds ratio 1.17, 95% confidence interval (CI) 1.03 – 1.32], and fewer peritonitis episodes in December (odds ratio 0.79, 95% CI 0.61 – 0.98). There was also a trend of more peritonitis in March (odds ratio 1.18, 95% CI 0.97 – 1.41), but the difference was not statistically significant. When the incidence of peritonitis caused by individual bacterial species was further analyzed, we found a significant seasonal variation in the rate of peritonitis caused by gram-negative bacteria, except Pseudomonas (overall chi-square test, p = 0.002). A similar trend of seasonal variation was also observed in gram-positive peritonitis, but the result was not statistically significant. There was significant seasonal variation in the rate of peritonitis that had coexisting exit-site infection (overall chi-square test, p = 0.02), with peak incidence in July. However, the proportion of peritonitis that had coexisting exit-site infection did not have significant seasonal variation. There was significant correlation between monthly peritonitis rate and average humidity ( r = –0.346, p < 0.002) and temperature ( r = –0.264, p = 0.015).

Conclusions

There is substantial seasonal variation in the incidence of dialysis-related peritonitis, with peak incidence in the months that are hot and humid. Keeping a cool and dry living environment may help to reduce peritonitis in peritoneal dialysis patients in tropical countries.

A Risk Analysis of Continuous Ambulatory Peritoneal Dialysis-Related Peritonitis

Objective

We studied the clinical characteristics that influence the risk of dialysis-related peritonitis complication in incident Chinese patients undergoing continuous ambulatory peritoneal dialysis (CAPD).

Methods

A single center, retrospective, observational cohort study was carried out to examine the risk factors of developing a first episode of dialysis-related peritonitis.

Results

Between 1995 and 2004, 246 incident CAPD patients were recruited for analysis. During the study period of 897.1 patient-years, 85 initial episodes of peritonitis were recorded. The median peritonitis-free time for diabetic subjects was significantly worse than for nondiabetic subjects (49.0 ± 10.5 vs 82.3 ± 12.6 months, p = 0.0019). The difference was due mainly to a higher likelihood of developing peritonitis with gram-negative organisms in patients with diabetes mellitus ( p = 0.038). Low serum albumin concentration was also associated with worse peritonitis-free survival. There was a nonsignificant trend toward an increased risk for peritonitis in the group of patients with cerebrovascular disease. According to multivariate Cox proportional hazards model for the analysis of time to first peritonitis episode, the two independent risk factors were presence of diabetes mellitus and initial serum albumin concentration. In particular, diabetes mellitus was associated with a hazard ratio of 1.50 and a 95% confidence interval of 1.05 – 2.40 ( p = 0.030) to develop an initial peritonitis. Lower serum albumin level at the start of CAPD was a significant predictor of peritonitis, with hazard ratio of 1.67 for every decrease of 10 g/L, and 95% confidence interval 1.08 – 2.60 ( p = 0.021).

Conclusions

Our results confirm the susceptibility of diabetic CAPD and hypoalbuminemic patients to peritonitis, and highlight the role of further studies in reducing this complication.

Treatment of Refractory Pseudomonas Aeruginosa Exit-Site Infection by Simultaneous Removal and Reinsertion of Peritoneal Dialysis Catheter

Background

Patients on continuous ambulatory peritoneal dialysis (CAPD) with Pseudomonas aeruginosa exit-site infection (ESI) refractory to antibiotic treatment often require replacement of their peritoneal dialysis catheter (PDC). The optimal interval between removal and reinsertion of the PDC is not known. There are relatively few data on the feasibility of simultaneous removal and reinsertion of dialysis catheters for the treatment of P. aeruginosa ESI.

Methods

We retrospectively reviewed the short- and long-term outcomes of all CAPD patients who had undergone simultaneous removal and reinsertion of their PDC for the treatment of refractory P. aeruginosa ESI in our hospital between January 1994 and December 2003. During the operation, the old catheter was removed first and a new catheter was inserted into the opposite side of the abdomen. All patients received 7 days of antibiotic therapy postoperatively. CAPD was resumed after 2 weeks of intermittent peritoneal dialysis.

Results

Over a 10-year period, 37 CAPD patients underwent the operation. Mean age of the patients was 59.5 ± 10.9 years. The interval between the diagnosis of ESI and the operation was 16.7 ± 6.9 weeks. The patients received 7.6 ± 2.5 weeks of antibiotic treatment before the procedure. Early postoperative complications were uncommon. None of the patients developed ESI within 4 weeks after the operation. At 1 year after the operation, 3 patients (8%) had developed recurrence of P. aeruginosa ESI 24 – 40 weeks postoperatively. Peritonitis due to P. aeruginosa was not observed.

Conclusions

We conclude that simultaneous removal and reinsertion of the PDC is feasible in eradicating refractory ESI due to P. aeruginosa. This procedure alleviates the need for temporary hemodialysis and allows continuation of peritoneal dialysis.

Continuous Ambulatory Peritoneal Dialysis in Patients with Hepatitis B Liver Disease

Objective

We hypothesized that patients with hepatitis B virus infection and cirrhosis are more susceptible to peritonitis as a complication of peritoneal dialysis (PD).

Methods

A retrospective study was carried out to compare peritonitis rates between cirrhotic and non-cirrhotic patients with hepatitis B virus infection.

Results

Between 1994 and 2004, 25 PD patients with hepatitis B cirrhosis and 36 patients with hepatitis B without cirrhosis were included for analysis. Mean follow-up duration was 52 months. Subjects with hepatitis B cirrhosis consisted of more males and had higher total body weight. No cirrhotic patients (20 of them being Child–Pugh class A, 2 class B, and 3 class C) had undergone portosystemic shunting or liver transplantation. Cirrhotic patients had slightly higher bilirubin concentration than the non-cirrhotic group (22 ± 50 vs 9 ± 4 μmol/L, p = 0.16). There was no difference in median peritonitis-free survival between cirrhotic and non-cirrhotic patients (40 vs 37 months, p = 0.64 by log-rank test). The average peritonitis rate was 1 episode every 19.2 patient-months in the cirrhotic group and 1 episode every 20.5 patient-months in the non-cirrhotic group. Time to first peritonitis did not differ between the two groups with respect to gram-negative organisms ( p = 0.88) or gram-positive organisms ( p = 0.52). Cirrhotic patients had more frequent Streptococcus species peritonitis, which accounted for 13% of all peritonitis episodes, as opposed to 2% among the non-cirrhotic patients ( p = 0.01). Overall treatment response rate and outcome did not differ between patients with and patients without cirrhosis.

Conclusions

Peritonitis-free survival of cirrhosis patients infected by hepatitis B virus compares favorably with that in patients without cirrhosis. The presence of liver cirrhosis does not appear to compromise PD outcome.

Cefazolin plus Ceftazidime versus Imipenem / Cilastatin Monotherapy for Treatment of Capd Peritonitis — a Randomized Controlled Trial

Background

Peritonitis is a serious complication of peritoneal dialysis (PD). We studied the efficacy of imipenem / cilastatin monotherapy in the treatment of PD-related peritonitis.

Methods

We performed an open-label, randomized control study comparing imipenem / cilastatin monotherapy (treatment group) versus cefazolin plus ceftazidime (control group) in the treatment of PD peritonitis. The result was further compared to a historic group treated with cefazolin plus netilmycin. Outcome measures were primary response rate at day 10 and complete cure rate.

Results

We enrolled 51 patients in the treatment group, 51 in the control group, and identified 96 in the historic group. The primary response rate to the assigned antibiotics was 49.0%, 51.0%, and 49.0% for the treatment, control, and historic groups, respectively ( p = 0.97). The primary response rate allowing for change in antibiotic was 82.4%, 90.2%, and 82.3%, respectively, for the three groups ( p = 0.41). The complete cure rate was 72.5%, 80.4%, and 82.3%, respectively ( p = 0.60). Tenckhoff catheter removal was needed in 6 cases in the treatment group, 6 cases in the control group, and 13 cases in the historic group ( p = 0.90).

Conclusions

We concluded that monotherapy of imipenem / cilastatin has similar efficacy compared to the two standard regimens of cefazolin plus ceftazidime or netilmycin in the treatment of PD peritonitis.

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.

Compatibility of aztreonam in four commercial peritoneal dialysis fluids

The preferable route for treatment of peritoneal dialysis related peritonitis remains the intraperitoneal administration of antibiotics admixed to peritoneal dialysis fluids. It is important to know whether the administered drug is compatible with the PD fluids and its container. In the present study the compatibility of aztreonam with four commercial PDFs at storing temperatures and duration representative for storing conditions in the clinical settings was investigated. Aztreonam concentrations were determined using high-performance liquid chromatography. The antimicrobial activity of aztreonam was evaluated using an E. coli diffusion disk inhibition assay and P. aeruginosa time-kill curves. In Extraneal evaluated at 6 °C, 25 °C and 37 °C aztreonam was stable over the whole study period of 14 days and 24 hours, respectively. In Physioneal and Nutrineal aztreonam was stable at 6 °C for up to 14 days. Antimicrobial activity was retained in all PD fluids over the whole study period. Aztreonam remained stable and was compatible with the PD fluids, particularly with Extraneal or Nutrineal, and no compensatory dose adjustment is needed when stored for up to 14 days at refrigeration temperature before use.

Peritoneal Microbiome in End-Stage Renal Disease Patients and the Impact of Peritoneal Dialysis Therapy

Factors influencing the occurrence of peritoneal dialysis (PD)-related infections are still far from fully understood. Recent studies described the existence of specific microbiomes in body sites previously considered microbiome-free, unravelling new microbial pathways in the human body. In the present study, we analyzed the peritoneum of end-stage kidney disease (ESKD) patients to determine if they harbored a specific microbiome and if it is altered in patients on PD therapy. We conducted a cross-sectional study where the peritoneal microbiomes from ESKD patients with intact peritoneal cavities (ESKD non-PD, n = 11) and ESKD patients undergoing PD therapy (ESKD PD, n = 9) were analyzed with a 16S rRNA approach. Peritoneal tissue of ESKD patients contained characteristically low-abundance microbiomes dominated by Proteobacteria, Firmicutes, Actinobacteria, and Bacteroidetes. Patients undergoing PD therapy presented lower species richness, with dominance by the Pseudomonadaceae and Prevotelaceae families. This study provides the first characterization of the peritoneal microbiome in ESKD patients, bringing new insight to the human microbiome. Additionally, PD therapy may induce changes in this unique microbiome. The clinical relevance of these observations should be further explored to uncover the role of the peritoneal microbiome as a key element in the onset or aggravation of infection in ESKD patients, especially those undergoing PD.

Repeat Peritoneal Dialysis Exit-Site Infection: Definition and Outcomes

Background:The most common complication of peritoneal dialysis (PD) is infection. Despite this, there are no clear guidelines for the management of repeat exit-site infection (ESI), and best practice is not known. We describe our unit's experience of repeat ESI and clinical outcomes in this cohort.Methods:Retrospective case note review of all PD patients with positive ESI swabs at our center between 1 January 2012 and 1 January 2018. Patients were included in the study if they had 2 or more ESI with the same organism within a 12-month period and an initial positive response to antibiotic therapy.Results:Overall, 31 of 248 patients had repeat ESI. The 2 most common causative organisms were Staphylococcus aureus (n = 16, 52%) and Pseudomonas aeruginosa (n = 10, 32%). Twenty (65%) patients developed subsequent peritonitis. The infection resolved with further antibiotics alone in 10 (32%) patients and in 6 patients after PD catheter exchange. The PD catheter was removed in 16 (52%) patients (including 5 after an initial catheter exchange) requiring transfer to hemodialysis (HD). Six (19%) patients died within 12 months of repeat ESI. Both repeat Pseudomonas aeruginosa and Staphylococcus aureus infections were associated with high rates of dialysis modality change (70% and 50%, respectively).Conclusion:We have developed the first definition for repeat ESI. Repeat ESI is clinically important and results in significant morbidity and mortality. Following repeat ESI, peritonitis rates are high and a significant number of patients switch dialysis modality. Studies are needed to determine whether interventions such as early catheter exchange would improve outcomes.

Peritoneal Dialysis-Associated Peritonitis

Peritonitis is a common and severe complication in peritoneal dialysis (PD). Detailed recommendations on the prevention and treatment of PD-associated peritonitis have been published by the International Society for Peritoneal Dialysis (ISPD), but there is a substantial variation in clinical practice among dialysis units. Prophylactic antibiotics administered before PD catheter insertion, colonoscopy, or invasive gynecologic procedures, daily topical application of antibiotic cream or ointment to the catheter exit site, and prompt treatment of exit site or catheter infection are key measures to prevent PD-associated peritonitis. When a patient on PD presents with clinical features compatible with PD-associated peritonitis, empirical antibiotic therapy, with coverage of both Gram-positive and Gram-negative organisms (including Pseudomonas species), should be started once the appropriate microbiologic specimens have been obtained. Intraperitoneal is the preferred route of administration. Antifungal prophylaxis, preferably oral nystatin, should be added to prevent secondary fungal peritonitis. Once the PD effluent Gram stain or culture and sensitivity results are available, antibiotic therapy can be adjusted accordingly. A detailed description on the dosage of individual antibiotic can be found in the latest recommendations by the ISPD. The duration of antibiotics is usually 2-3 weeks, depending on the specific organisms identified. Catheter removal and temporary hemodialysis support is recommended for refractory, relapsing, or fungal peritonitis. In some patients, a new PD catheter could be inserted after complete resolution of the peritonitis. PD catheter removal should also be considered for refractory exit site or tunnel infections. After the improvement in clinical practice, there is a worldwide trend of reduction in PD-associated peritonitis rate, supporting the use of PD as a first-line dialysis modality.

Peritoneal Infections in Children Undergoing Acute Peritoneal Dialysis at a Tertiary/Quaternary Central Hospital in Kwazulu-Natal, South Africa

Background

In a resource-limited setting, acute peritoneal dialysis (APD) is the modality of choice as a form of renal replacement therapy in children with acute kidney injury (AKI). However, there is a high risk of peritonitis that causes significant morbidity and mortality. Data on PD and peritonitis in developing countries are scarce. The purpose of this retrospective study was to determine the prevalence of APD-related peritonitis at a central referral hospital in KwaZulu-Natal, South Africa.

Methods

A retrospective study from January 2010 until December 2014 was done at Inkosi Albert Luthuli Central Hospital (IALCH). All children under the age of 13 years with AKI requiring APD were included in the study.

Results

Forty children were included in the study. Age ranged from 0.2 years to 12.25 years; 25 (62.5%) were male and 15 (37.5%) female. Twenty-seven (67.5%) were admitted to the intensive care unit (ICU) and 13 (32.5%) to the pediatric high care ward. Septicemia with multi-organ dysfunction was the was the main cause of AKI requiring APD in 18 (45%) children followed by poststreptococcal glomerulonephritis in 8 (20%). Acute PD was complicated by culture-proven peritonitis in 19 (47.5%) children of whom 16 (84.2%) had a single organism cultured while in 3, (15.7%) there was a mixed culture. The total number of organisms cultured was 24: 8 (33.3%) were gram-positive organisms, 12 (50%) gram-negative organisms, and 4 (16.67%) fungal. The Paediatric Index of Mortality (PIM) 2 Score risk of mortality was 99.4% for patients admitted to ICU. Mortality rate was 65%, and 14 (53%) of the children who demised had peritonitis.

Conclusion

This study showed an inordinately high complication rate of peritonitis, mostly secondary to gram-negative organisms, of children undergoing APD in a central referral hospital. The use of surgically placed, tunneled catheters, meticulous attention to aseptic techniques and judicious use of antimicrobials is highly recommended in reducing the incidence of peritonitis in children undergoing APD.

Stability of Meropenem and Piperacillin/Tazobactam with Heparin in Various Peritoneal Dialysis Solutions

BACKGROUND

Infections caused by ceftazidime-resistant Pseudomonas and extended-spectrum beta-lactamase (ESBL)-producing gram-negative bacteria are increasing worldwide. Meropenem and piperacillin/tazobactam (PIP/TZB) are recommended for the treatment of peritoneal dialysis-associated peritonitis (PDAP) caused by ceftazidime-resistant Pseudomonas and other resistant gram-negative bacteria. Patients may also receive intraperitoneal heparin to prevent occlusion of their catheters. However, the stability of meropenem or PIP/TZB, in combination with heparin, in different types of peritoneal dialysis (PD) solutions used in clinical practice is currently unknown. Therefore, we investigated the stability of meropenem and PIP/TZB, each in combination with heparin, in different PD solutions.

METHODS

A total of 15 PD bags (3 bags for each type of PD solution) containing meropenem and heparin and 24 PD bags (3 bags for each type of PD solution) containing PIP/TZB and heparin were prepared and stored at 4°C for 168 hours. The same bags were stored at 25°C for 3 hours followed by 10 hours at 37°C. An aliquot withdrawn before storage and at defined time points was analyzed for the concentration of meropenem, PIP, TZB, and heparin using high-performance liquid chromatography. Samples were also analysed for particle content, pH and color change, and the anticoagulant activity of heparin.

RESULTS

Meropenem and heparin retained more than 90% of their initial concentration in 4 out of 5 types of PD solutions when stored at 4°C for 168 hours, followed by storage at 25°C for 3 hours and then at 37°C for 10 hours. Piperacillin/tazobactam and heparin were found to be stable in all 8 types of PD solutions when stored under the same conditions. Heparin retained more than 98% of its initial anticoagulant activity throughout the study period. No evidence of particle formation, color change, or pH change was observed at any time under the storage conditions employed in the study.

CONCLUSIONS

This study provides clinically important information on the stability of meropenem and PIP/TZB, each in combination with heparin, in different PD solutions. The use of meropenem-heparin admixed in pH-neutral PD solutions for the treatment of PDAP should be avoided, given the observed suboptimal stability of meropenem.

Peritoneal dialysis-related peritonitis: challenges and solutions

Peritoneal dialysis is an effective treatment modality for patients with end-stage renal disease. The relative use of peritoneal dialysis versus hemodialysis varies widely by country. Data from a 2004 survey reports the percentage of patients with end-stage renal disease treated with peritoneal dialysis to be 5%-10% in economically developed regions like the US and Western Europe to as much as 75% in Mexico. This disparity is probably related to the availability and access to hemodialysis, or in some cases patient preference for peritoneal over hemodialysis. Peritoneal dialysis-related peritonitis remains the major complication and primary challenge to the long-term success of peritoneal dialysis. Fifty years ago, with the advent of the Tenckhoff catheter, patients averaged six episodes of peritonitis per year on peritoneal dialysis. In 2016, the International Society for Peritoneal Dialysis proposed a benchmark of 0.5 episodes of peritonitis per year or one episode every 2 years. Despite the marked reduction in peritonitis over time, peritonitis for the individual patient is problematic. The mortality for an episode of peritonitis is 5% and is a cofactor for mortality in another 16% of affected patients. Prevention of peritonitis and prompt and appropriate management of peritonitis is essential for the long-term success of peritoneal dialysis in all patients. In this review, challenges and solutions are addressed regarding the pathogenesis, clinical features, diagnosis, treatment, and prevention of peritoneal dialysis-related peritonitis from the viewpoint of an infectious disease physician.

Peritoneal dialysis-related peritonitis caused by Pseudomonas species: Insight from a post-millennial case series

Background

Pseudomonas peritonitis is a serious complication of peritoneal dialysis (PD). However, the clinical course of Pseudomonas peritonitis following the adoption of international guidelines remains unclear.

Methods

We reviewed the clinical course and treatment response of 153 consecutive episodes of PD peritonitis caused by Pseudomonas species from 2001 to 2015.

Results

Pseudomonas peritonitis accounted for 8.3% of all peritonitis episodes. The bacteria isolated were resistant to ceftazidime in 32 cases (20.9%), and to gentamycin in 18 cases (11.8%). In 20 episodes (13.1%), there was a concomitant exit site infection (ESI); in another 24 episodes (15.7%), there was a history of Pseudomonas ESI in the past. The overall primary response rate was 53.6%, and complete cure rate 42.4%. There was no significant difference in the complete cure rate between patients who treated with regimens of 3 and 2 antibiotics. Amongst 76 episodes (46.4%) that failed to respond to antibiotics by day 4, 37 had immediate catheter removal; the other 24 received salvage antibiotics, but only 6 achieved complete cure.

Conclusions

Antibiotic resistance is common amongst Pseudomonas species causing peritonitis. Adoption of the treatment guideline leads to a reasonable complete cure rate of Pseudomonas peritonitis. Treatment with three antibiotics is not superior than the conventional two antibiotics regimen. When there is no clinical response after 4 days of antibiotic treatment, early catheter removal should be preferred over an attempt of salvage antibiotic therapy.

Dialysate bacterial endotoxin as a prognostic indicator of peritoneal dialysis related peritonitis

Peritonitis is the major complication of peritoneal dialysis (PD). The aim of our present study is to explore the prognostic value of endotoxin level in PD effluent for the prediction of treatment failure in PD-related peritonitis. We studied 325 peritonitis episodes in 223 patients. PD effluent (PDE) was collected every 5 days for endotoxin level and leukocyte count. Patients were followed for relapsing or recurrent peritonitis. We found 20 episodes (6.2%) had primary treatment failure; 41 (12.6%) developed relapsing, 19 (5.8%) had recurrent, and 22 (6.8%) had repeat episodes. Endotoxin was detectable in the PDE of 19 episodes (24.4%) caused by Gram negative organisms, 4 episodes (6.8%) of mixed bacterial growth, and none of the culture negative episodes or those by Gram positive organisms. For episodes caused by Gram negative bacteria, a detectable endotoxin level in PDE on day 5 had a sensitivity and specificity of 66.7% and 83.3%, respectively, for predicting primary treatment failure. In contrast, PDE leukocyte count > 1000 per mm3 on day 5 had a sensitivity and specificity of 88.9% and 89.1%, respectively; the addition of PDE endotoxin assay did not improve the sensitivity or specificity. We conclude that detectable endotoxin in PDE 5 days after antibiotic therapy might predict primary treatment failure in peritonitis episodes caused by Gram negative organisms. However, the sensitivity and specificity of PDE endotoxin assay was inferior to PDE leukocyte count.

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.

Deciphering the Contribution of Biofilm to the Pathogenesis of Peritoneal Dialysis Infections: Characterization and Microbial Behaviour on Dialysis Fluids

Infections are major complications in peritoneal dialysis (PD) with a multifactorial etiology that comprises patient, microbial and dialytic factors. This study aimed at investigating the contribution of microbial biofilms on PD catheters to recalcitrant infections and their interplay with PD related-factors. A prospective observational study was performed on 47 patients attending Centro Hospitalar of Porto and Vila Nova de Gaia/Espinho to whom the catheter was removed due to infectious (n = 16) and non-infectious causes (n = 31). Microbial density on the catheter was assessed by culture methods and the isolated microorganisms identified by matrix-assisted laser desorption/ionization time-of-flight intact cell mass spectrometry. The effect of conventional and three biocompatible PD solutions on 16 Coagulase Negative Staphylococci (CNS) and 10 Pseudomonas aeruginosa strains planktonic growth and biofilm formation was evaluated. Cultures were positive in 87.5% of the catheters removed due infectious and 90.3% removed due to non-infectious causes. However, microbial yields were higher on the cuffs of catheters removed due to infection vs. non-infection. Staphylococci (CNS and Staphylococcus aureus) and P. aeruginosa were the predominant species: 32% and 20% in the infection and 43.3% and 22.7% in the non-infection group, respectively. In general, PD solutions had a detrimental effect on planktonic CNS and P. aeruginosa strains growth. All strains formed biofilms in the presence of PD solutions. The solutions had a more detrimental effect on P. aeruginosa than CNS strains. No major differences were observed between conventional and biocompatible solutions, although in icodextrin solution biofilm biomass was lower than in bicarbonate/lactate solution. Overall, we show that microbial biofilm is universal in PD catheters with the subclinical menace of Staphylococci and P. aeruginosa. Cuffs colonization may significantly contribute to infection. PD solutions differentially impact microbial species. This knowledge is important for the development of infection diagnosis, treatment and preventive strategies.

A qualitative systematic review of the literature supporting a causal relationship between exit-site infection and subsequent peritonitis in patients with end-stage renal disease treated with peritoneal dialysis

OBJECTIVE

The objective of our research was to summarize and review evidence supporting a causal relationship between exit-site infection and peritonitis in peritoneal dialysis (PD) patients.

DATA SOURCES

We undertook a qualitative review of studies retrieved from MEDLINE, EMBASE, and PubMed, and supplemented that process with a hand search of references and abstracts in the literature.

STUDY SELECTION

Our quality criteria were based on the Paediatric Risk of Mortality guidelines, definitions, and recommendations from the International Society for Peritoneal Dialysis (ISPD), and the Bradford Hill criteria for causality. All identified abstracts were reviewed for content. Of 776 abstracts, 59 were selected for full-text evaluation, and 22 of those met the ISPD criteria for good-quality research in PD-related infections. Of the 22 eligible studies, 9 met the study's quality criteria and were included in the summative analysis. No articles reported sufficient data for a quantitative analysis.

DATA EXTRACTION

Information on study design, study population characteristics, definitions, peritonitis rates, exit-site care protocol, exit-site treatment protocol, follow-up period, potential bias, and outcomes was extracted. Criteria for including data in the final study were determined using ISPD guidelines.

DATA SYNTHESIS

Of the 9 included studies, 8 suggested that a history of exit-site infection increased the risk for subsequent peritonitis. Of those studies, 3 met 5 causality criteria, 4 met 4 causality criteria, and 1 met 3 causality criteria.

CONCLUSIONS

The literature provides weak evidence to support a causal relationship between exit-site infection and subsequent peritonitis. Few criteria for causation were met. We were unable to attribute causation and could assume an association only. The exclusion of studies focusing on PD-related tunnel infections may be viewed as both a strength and a limitation of the present work.

Acidosis potentiates the host proinflammatory interleukin-1β response to Pseudomonas aeruginosa infection

Infection by Pseudomonas aeruginosa, and bacteria in general, frequently promotes acidification of the local microenvironment, and this is reinforced by pulmonary exertion and exacerbation. However, the consequence of an acidic environment on the host inflammatory response to P. aeruginosa infection is poorly understood. Here we report that the pivotal cellular and host proinflammatory interleukin-1β (IL-1β) response, which enables host clearance of the infection but can produce collateral inflammatory damage, is increased in response to P. aeruginosa infection within an acidic environment. Synergistic mechanisms that promote increased IL-1β release in response to P. aeruginosa infection in an acidic environment are increased pro-IL-1β induction and increased caspase-1 activity, the latter being dependent upon a functional type III secretion system of the bacteria and the NLRC4 inflammasome of the host. Using an in vivo peritonitis model, we have validated that the IL-1β inflammatory response is increased in mice in response to P. aeruginosa infection within an acidic microenvironment. These data reveal novel insights into the regulation and exacerbation of inflammatory responses to P. aeruginosa.

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.

Bacteria-derived DNA fragment in peritoneal dialysis effluent as a predictor of relapsing peritonitis

BACKGROUND AND OBJECTIVES

Relapsing and recurrent peritonitis episodes are important causes of treatment failure in patients undergoing peritoneal dialysis (PD). This study explored whether the level of bacteria-derived DNA fragment in PD effluent predicts the development of relapsing or recurrent peritonitis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The study included 143 patients with PD peritonitis in a dialysis unit between September 2010 and December 2011. Every 5 days until antibiotic treatment ended, PD effluent was collected to determine bacteria-derived DNA fragment level, which is represented by the number of PCR cycles at which bacterial DNA could be detected. Patients were followed for the development of relapsing or recurrent peritonitis.

RESULTS

Thirty-nine patients were excluded because of immediate treatment failure or incorrect diagnosis. Of the other 104 patients, 15 (14.4%) developed relapsing peritonitis, 3 (2.9%) had recurrent peritonitis, and 5 (4.8%) had repeat episodes. Patients with relapsing or recurrent peritonitis episodes had significantly higher levels of bacterial DNA fragment in PD effluent than those without relapsing or recurrence, both 5 days before (31.9 ± 3.4 versus 34.3 ± 3.0 cycles; P=0.002) and on the day of (32.3 ± 2.6 versus 34.1 ± 1.7 cycles; P<0.001) completion of antibiotics. When bacterial DNA fragment detectable by 34 PCR cycles 5 days before the completion of antibiotics is used as the cutoff, it has a sensitivity of 88.9% and specificity of 60.5% for the prediction of relapsing or recurrent peritonitis.

CONCLUSIONS

Bacterial DNA fragment levels in PD effluent are significantly higher, both 5 days before and on the date of completion of antibiotics, among patients who subsequently develop relapsing or recurrent peritonitis than among those cured by antibiotics. Further studies are needed to validate these results and confirm the clinical utility of dialysate bacterial DNA fragment level.

Prevention of peritoneal dialysis catheter infections in Saudi peritoneal dialysis patients: the emergence of high-level mupirocin resistance

PURPOSE

Exit-site infection (ESI) and peritonitis remain the major causes of morbidity and mortality in peritoneal dialysis (PD) patients. This study compared the effectiveness of local mupirocin ointment and gentamicin cream in preventing both gram-positive and gram-negative bacterial infections in PD patients.

METHODS

Patients from two centers (n = 203) were assigned to daily mupirocin ointment or gentamicin cream application. Infections were tracked prospectively by organisms and expressed as episodes per patient-year for both ESI and peritonitis.

RESULTS

The rate of gram-positive ESI was 0.31/episode/patient-year and 0.22 episodes/patient-year (p<0.05), whereas the rate of gram-negative ESI was 0.28 episode/patient-year and 0.11 episode/patient-year (p<0.01) in the mupirocin group and gentamicin group, respectively. Gram-positive ESI occurred in 17.1% vs 10.2% of patients (p<0.05), whereas 20% of and 5.1% of patients (p<0.001) had gram-negative ESI in the 2 groups respectively. S.aureus was cultured at exit-site in the mupirocin group in 27.8% patients, 60% (16.7% of the total Gram-positive isolates) of them being with high-level mupirocin-resistance. Pseudomonas aeruginosa was cultured in 21.8% of ESI in the mupirocin group, and in only 6.7% in the gentamicin group (p<0.01). Peritonitis rates were lower using gentamicin cream, 0.17 episode/patient-year compared with mupirocin, 0.39 episode/patient-year (p<0.01). With multivariate analysis, only gentamicin exit-site use was a significant predictor for lower catheter infection rate.

CONCLUSION

Prolonged use of mupirocin for ESI-prophylaxis is associated with the emergence of mupirocin-resistant S. aureus. Gentamicin cream is superior to mupirocin ointment in the prevention of PD catheter infections.

Campylobacter peritonitis complicating peritoneal dialysis: a review of 12 consecutive cases

BACKGROUND

Peritoneal dialysis-associated peritonitis secondary to Campylobacter organisms is uncommon. Few studies have assessed either treatment or clinical outcomes.

METHODS

We reviewed all Campylobacter peritonitis episodes occurring in a single dialysis unit from 1994 to 2011.

RESULTS

During the study period, 12 episodes of Campylobacter peritonitis (0.45% of all peritonitis episodes) were recorded. Diarrhea was uncommon (8.3%). The overall primary response rate was 91.7%; the complete cure rate was 75.0%. Among 6 patients who failed to respond to standard antibiotics by day 5, all improved after administration of an oral macrolide (erythromycin or clarithromycin). Of those 6 patients, 5 experienced a complete cure, and 1 patient experienced relapse of culture-negative peritonitis. No patient required Tenckhoff catheter removal or temporary hemodialysis support. The 30-day mortality was 0%.

CONCLUSIONS

Campylobacter peritonitis might not respond to first-line conventional antibiotics, and an oral macrolide is recommended if Campylobacter is confirmed. The findings from our analysis do not support the use of fluoroquinolone, which is associated with a high resistance rate.

An intra-abdominal abscess or "rind" as a consequence of peritoneal dialysis-associated pseudomonas peritonitis

Background: Abdominal CT imaging has defined characteristics of two pathological entities specific to peritoneal dialysis patients. Both are associated with serious peritoneal complications. One is comprised of ascites accompanied by septation and loculated fluid pockets as a complication of bacterial peritonitis. The other is the syndrome of encapsulating peritoneal sclerosis. We present the evolution of a single, thick-walled fluid collection as a consequence of relapsing Pseudomonas aeruginosa peritonitis. The entity had distinctive features differing from either of the two previously described entities, and to our knowledge, has not been described previously. Our patient’s radiological evolution resembled the formation of a pleural or peritoneal “rind.” Conclusion: Peritonitis, as a result of Pseudomonas aeruginosa, may lead to “rind” formation as described with empyemas and is distinct from previously described intra-abdominal pathologies in peritoneal dialysis patients.