Pseudomonas peritonitis in peritoneal dialysis patients: the Network #9 Peritonitis Study

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

TRIAL REGISTRATION

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

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.

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

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

Predictors of Outcome following Bacterial Peritonitis in Peritoneal Dialysis

Objective

No studies have been done to examine factors that predict the outcome of bacterial peritonitis during peritoneal dialysis (PD), beyond the contribution of the organism causing the peritonitis, concurrent exit-site or tunnel infection, and abdominal catastrophes.

Design

In this study we examined several clinical and laboratory parameters that might predict the outcome of an episode of bacterial peritonitis. Between March 1995 and July 2000, we identified 399 episodes of bacterial peritonitis in 191 patients on dialysis.

Results

There were 260 episodes of gram-positive peritonitis, 99 episodes of gram-negative peritonitis, and 40 episodes of polymicrobial peritonitis. Gram-positive peritonitis had a significantly higher resolution rate than either polymicrobial peritonitis or gram-negative peritonitis. Staphylococcus aureus episodes had poorer resolution than other gram-positive infections. Nonpseudomonal peritonitis had a better outcome than Pseudomonas aeruginosa episodes. Among all the gram-negative infections, Serratia marcescens had the worst outcome. Episodes associated with a purulent exit site had poor outcome only on univariate analysis. For those peritonitis episodes in which the PD fluid cell count was > 100/μL for more than 5 days, the nonresolution rate was 45.6%, compared to a 4.2% nonresolution rate when the cell count returned to 100/μL or less in less than 5 days. Those patients that had a successful outcome had been on continuous ambulatory PD for a significantly shorter period of time than those patients that had nonresolution. The nonresolution rate for those patients that had been on PD for more than 2.4 years was 24.4%, compared to 16.5% for those that had been on PD for less than 2.4 years ( p = 0.05).

Conclusion

The duration of PD and the number of days the PD effluent cell count remained > 100/μL were the only factors that independently predicted the outcome of an episode of peritonitis. Caucasians seem to have a higher nonresolution (failure) rate compared to Blacks. Other variables, such as the number of peritonitis episodes before the episode in question, vancomycin-based initial empiric treatment, serum albumin level, total lymphocyte count and initial dialysate white blood cell count, age, sex, diabetes, previous renal transplantation, and the use of steroids did not affect the outcome of peritonitis.

Recurrent Infection and Catheter Loss in Patients on Continuous Ambulatory Peritoneal Dialysis

Objective

To elucidate the factors leading to catheter loss from recurrent infection in patients on continuous ambulatory peritoneal dialysis (CAPD).

Design

All catheters removed from patients were prospectively examined for infection.

Setting

CAPD unit in large tertiary-care general hospital.

Patients

Sixty-five consecutive patients undergoing catheter removal for whatever cause; 20 catheters rejected because of desiccation or contamination in transit.

Interventions

None.

Main Outcome Measures

Micro-organisms linked to catheter removal; their locations on removed catheters.

Results

Of 45 catheters removed between January 1994 and August 1995, 26 were infected: 13/26 infections were caused by Staphylococcus aureus and 7/26 by Pseudomonas aeruginosa. In only one case was S. epidermidis associated with catheter removal. The most striking finding was that the inner cuff harbored large numbers of the infecting organisms, even when antibiotics had eradicated them from the peritoneal cavity and exit site, where present, and the catheter lumen.

Conclusion

The importance of S. aureus and Ps. aeruginosa rather than S. epidermidis in catheter loss due to relapsing infection is confirmed. Persistence of the causative organisms in the inner cuff is a likely explanation for relapse after treatment, and might be due to the predominantly intraperitoneal administration of antibiotics. A clinical trial of the effect on catheter retention of empirical use of systemic or oral agents that give high tissue levels and are active against intracellular microorganisms, along with recommended intraperitoneal regimens, is indicated.

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-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.

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.

Clinical and microbiological characteristics of peritoneal dialysis-related peritonitis caused by Klebsiella pneumoniae in southern Taiwan

BACKGROUND/PURPOSE(S)

Gram-negative peritonitis is a frequent and serious complication of peritoneal dialysis (PD). No previous reports have focused on Klebsiella pneumoniae infection. The aim of this study was to investigate the host and bacterial factors associated with K. pneumoniae PD-related peritonitis.

METHODS

We retrospectively studied K. pneumoniae PD-peritonitis cases treated at a university hospital in southern Taiwan during 1990-2011, and analyzed the clinical features and outcomes and bacterial characteristics of serotypes, hypermucoviscosity (HV), and virulence-associated genes such as wabG, uge, and rmpA in K. pneumoniae PD-related peritonitis. Fifty-four isolates of K. pneumoniae-related community-acquired urinary tract infection (UTI) and 76 morphologically different nonpathogenic K. pneumoniae isolates from healthy adults were used as controls.

RESULTS

K. pneumoniae was the second most common monomicrobial pathogen causing Gram-negative PD-related peritonitis (n = 13, 2.7%), and the most common pathogen involved in polymicrobial peritonitis (16/43, 37.2%) and associated with high catheter removal rate (7/16, 43.8%). Compared with Escherichia coli peritonitis cases, patients with monomicrobial K. pneumoniae peritonitis also had insignificantly higher incidence of sepsis/bacteremia [n = 5 (38%), p = 0.11] and a higher mortality rate [n = 3 (23%), p = 0.36]. The prevalence of K1/K2 (n = 1, 7.7%) serotypes was low, but there was a higher prevalence of serotype K20 (n = 3, 23.1%) in K. pneumoniae isolates derived from monomicrobial PD-related peritonitis compared with control groups. HV phenotype (p < 0.001) and rmpA genotype (p = 0.007) were absent in the peritonitis group.

CONCLUSION

This is the first study focused on clinical and microbiological characteristics of K. pneumoniae PD-related peritonitis. K. pneumoniae was a common Gram-negative pathogen causing monomicrobial and polymicrobial PD-related peritonitis in southern Taiwan. The bacterial characteristics with low percentage of capsular serotype K1/K2, no significant HV, and absence of rmpA suggest a different pathogenesis in K. pneumoniae PD-related peritonitis compared with that in UTI and liver abscess.

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.

The association between exit site infection and subsequent peritonitis among peritoneal dialysis patients

BACKGROUND AND OBJECTIVES

Peritonitis is the most common infectious complication seen in peritoneal dialysis (PD). Traditionally, exit site infection (ESI) has been thought to predispose PD patients to peritonitis, although the risks have not been quantified. This study aimed to quantify the risk of PD peritonitis after ESI.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Data from 203 clinically stable PD patients >18 years of age who were followed as part of a randomized controlled trial over 18 months were used to estimate the risk of developing peritonitis within 30 days of an ESI compared with individuals who did not have a recent ESI. Sensitivity analyses were performed at 15, 45, and 60 days.

RESULTS

Patients were mostly male (64.5%) and Caucasian, with a mean age of 60.5 ± 14.4 years. There were 44 ESIs and 87 peritonitis episodes during the 18-month study. Seven patients had an ESI followed by peritonitis within 30 days. Using a frailty model, patients who had an ESI had a significantly higher risk of developing peritonitis within 30 days, even if the ESI was appropriately treated. This risk was maximal early on and diminished with time, with hazard ratios (95% confidence interval) of 11.1 at 15 days (HR=11.1, 95% CI=4.9-25.1), 5.3 at 45 days (2.5-11.3), and 4.9 at 60 days (2.4-9.9). In 2.3% of patients, subsequent peritonitis was caused by the same organism as the previous ESI.

CONCLUSIONS

A strong association between a treated ESI and subsequent PD peritonitis was present up to 60 days after initial diagnosis.

Infectious complications in dialysis--epidemiology and outcomes

This Review focuses on the changing epidemiology of infections among patients with end-stage renal disease who are undergoing dialysis. In particular, bloodstream infections related to vascular access in patients undergoing hemodialysis, and peritonitis in patients undergoing peritoneal dialysis, are highlighted. Gram-positive (staphylococcal and enterococcal) bloodstream infections and Gram-negative peritonitis (especially extended-spectrum β-lactamase-producing organisms) contribute substantially to excess health-care use owing to infection caused by dialysis access. Although the management of peritoneal-dialysis-related peritonitis has been hampered by a dearth of randomized, controlled studies, epidemiological data have provided useful information. To overcome the problem of differing methods used to monitor infections within various dialysis centers, uniform reporting systems for vascular-access-related infection and peritoneal-dialysis-related peritonitis, as recommended by the Centers for Disease Control and Prevention and the International Society for Peritoneal Dialysis, respectively, are discussed. Infections unrelated to the port of entry for dialysis are also examined, namely hepatitis and respiratory infection. To address the disease burden, we examine the infection-related mortality as well as the implications for subsequent cardiovascular mortality.

Prevention of peritoneal dialysis-related infections

Despite substantial advances in peritoneal dialysis (PD) as a renal replacement modality, PD-related infection remains an important cause of morbidity, technique failure, and mortality. This review describes the microbiology and outcomes of PD peritonitis and catheter infection, followed by a discussion of several strategies that may reduce the risk of PD-related infections. Strategies that are reviewed include use of antibiotics at the time of PD catheter insertion, selection of PD catheter design and insertion technique, patient training, PD connectology, exit site prophylaxis, periprocedural prophylaxis, fungal prophylaxis, and choice of PD solutions.

Microbiology and outcomes of peritonitis in Australian peritoneal dialysis patients

We analyzed data from the Australia and New Zealand Dialysis and Transplant Registry for 1 October 2003 to 31 December 2008 with the aim of describing the nature of peritonitis, therapies, and outcomes in patients on peritoneal dialysis (PD) in Australia. At least 1 episode of PD was observed in 6639 patients. The overall peritonitis rate was 0.60 episodes per patient-year (95% confidence interval: 0.59 to 0.62 episodes), with 6229 peritonitis episodes occurring in 3136 patients. Of those episodes, 13% were culture-negative, and 11% were polymicrobial. Gram-positive organisms were isolated in 53.4% of single-organism peritonitis episodes, and gram-negative organisms, in 23.6%. Mycobacterial and fungal peritonitis episodes were rare. Initial antibiotic therapy for most peritonitis episodes used 2 agents (most commonly vancomycin and an aminoglycoside); in 77.2% of episodes, therapy was subsequently changed to a single agent. Tenckhoff catheter removal was required in 20.4% of cases at a median of 6 days, and catheter removal was more common in fungal, mycobacterial, and anaerobic infections, with a median time to removal of 4 - 5 days. Peritonitis was the cause of death in 2.6% of patients. Transfer to hemodialysis and hospitalization were frequent outcomes of peritonitis. There was no relationship between center size and peritonitis rate. The peritonitis rate in Australia between 2003 and 2008 was higher than that reported in many other countries, with a particularly higher rate of gram-negative peritonitis.

Pseudomonas peritonitis in Australia: predictors, treatment, and outcomes in 191 cases

BACKGROUND AND OBJECTIVES

Pseudomonas peritonitis is a serious complication of peritoneal dialysis. To date, there as been no comprehensive, multicenter study of this condition.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The predictors, treatment, and clinical outcomes of Pseudomonas peritonitis were examined by binary logistic regression and multilevel, multivariate Poisson regression in all Australian PD patients in 66 centers between 2003 and 2006.

RESULTS

A total of 191 episodes of Pseudomonas peritonitis (5.3% of all peritonitis episodes) occurred in 171 individuals. Its occurrence was independently predicted by Maori/Pacific Islander race, Aboriginal/Torres Strait Islander race, and absence of baseline peritoneal equilibration test data. Compared with other organisms, Pseudomonas peritonitis was associated with greater frequencies of hospitalization (96 versus 79%; P = 0.006), catheter removal (44 versus 20%; P < 0.001), and permanent hemodialysis transfer (35 versus 17%; P < 0.001) but comparable death rates (3 versus 2%; P = 0.4). Initial empiric antibiotic choice did not influence outcomes, but subsequent use of dual anti-pseudomonal therapy was associated with a lower risk for permanent hemodialysis transfer (10 versus 38%, respectively; P = 0.03). Catheter removal was associated with a lower risk for death than treatment with antibiotics alone (0 versus 6%; P < 0.05).

CONCLUSIONS

Pseudomonas peritonitis is associated with high rates of catheter removal and permanent hemodialysis transfer. Prompt catheter removal and use of two anti-pseudomonal antibiotics are associated with better outcomes.

Determinants of Catheter Loss following Continuous Ambulatory Peritoneal Dialysis Peritonitis

Background

Few patients are able to resume peritoneal dialysis (PD) therapy after an episode of peritonitis that requires catheter removal. PD catheter loss is therefore regarded as an important index of patient morbidity. The aim of the present study was to evaluate factors influencing catheter loss in patients suffering from continuous ambulatory PD (CAPD) peritonitis.

Patients and Methods

We retrospectively reviewed 579 episodes of CAPD peritonitis from 1999 to 2006 in a tertiary-care referral hospital. Demographic, biochemical, and microbiological characteristics were recorded. Episodes resulting in PD catheter removal ( n = 68; 12%) were compared by both univariate and multivariate analyses with those in which PD catheters were preserved.

Results

The incidence of PD catheter loss increased as the number of organisms cultured increased ( p = 0.001). Also, PD catheter removal was more likely to occur after peritonitis episodes with low serum albumin level ( p = 0.004), those with long duration of PD effluent leukocyte count remaining above 100/μL ( p < 0.001), those with concomitant tunnel infection ( p < 0.001), those with concomitant exit-site infection ( p = 0.005), and those with presence of catastrophic intra-abdominal visceral events ( p < 0.001). Duration on PD preceding the peritonitis episode was of borderline significance ( p = 0.080). On the contrary, initial PD effluent leukocyte count and serum level of C-reactive protein were not predictive of PD catheter loss. Micro-organisms of the Enterobacteriaceae family were the major pathogens responsible for PD catheter loss following polymicrobial peritonitis. Furthermore, we found that there was no association between polymicrobial peritonitis and the catastrophic intra-abdominal visceral event, although both resulted in a greater incidence of PD catheter loss. Among the single-organism group in our population, the microbiological determinants of PD catheter loss included fungi ( p < 0.001), anaerobes ( p = 0.018), and Pseudomonas sp (borderline significance: p = 0.095).

Conclusion

PD catheter loss as a consequence of peritonitis is related primarily to hypoalbuminemia, longer duration of PD effluent leukocyte count remaining above 100/μL, the etiologic source of the infection, and the organism causing the infection. Peritonitis associated with concomitant tunnel or exit-site infections and abdominal catastrophes were more likely to proceed to PD catheter loss. The microbiological determinants of PD catheter loss in the present study included polymicrobial infections caused by Enterobacteriaceae as well as monomicrobial pseudomonal, anaerobic, and fungal infections.

Microbiology and outcomes of peritonitis in North America

A proper understanding of the patterns of occurrence of infectious complications in patients on peritoneal dialysis (PD) is crucial to lay the foundation for interventions directed at the major causes and predisposing factors. The present work is an initial report of a survey based on a large representative database of the infectious complications of PD. Gram-positive organisms accounted for 62% of peritonitis episodes in the US and 61% of these episodes in Canada. Gram-negative organisms accounted for 20.5% of episodes in the US and 23.6% of episodes in Canada. The peritoneal catheter was removed in 18% of the episodes in the US and 16% in Canada. Less than 4% of the episodes resulted in death. Gram-positive organisms accounted for the majority of exit-site infections in the US (69%) and Canada (76%). Gram-negative organisms accounted for a third of exit-site infections and among Gram-negative organisms Pseudomonas was the overwhelmingly dominant organism. The microbiology of exit-site infections revealed the expected representation of Gram-positive organisms. An important finding, however, is the significantly high contribution of Gram-negative organisms. Our findings can inform future guideline development and suggest that similar endeavors be undertaken in other parts of the world.

Diagnosis and management of enteric disease and abdominal catastrophe in peritoneal dialysis patients with peritonitis

Peritoneal dialysis (PD)-associated peritonitis rates have decreased significantly in recent years, especially Staphylococcus epidermidis and Staphylococcus aureus infections. Rates of gram-negative, polymicrobial, and fungal peritonitis have remained steady. The reported mortality of gram-negative and polymicrobial peritonitis varies widely (4%-50%). Most likely, the reason for this variability is that prognosis depends on the underlying etiology more than the specific microorganisms isolated. Gram-negative, polymicrobial, and fungal infection have variable association with documented visceral disease, and the highest mortality occurs in reports with the highest prevalence of intra-abdominal pathology. The odds ratio of death in PD patients with documented abdominal catastrophe and peritonitis is reported to be 20:1 compared with all other causes. Further reductions in PD-associated peritonitis mortality are likely to depend on earlier diagnosis and better management of intra-abdominal pathology. Presentation with hypotension, sepsis, lactic acidosis, and/or elevation of peritoneal fluid amylase should raise immediate concern for "surgical" peritonitis. Suspicion for visceral disease should also be high in patients with gram-negative, polymicrobial, and fungal infection or those who fail to improve rapidly as judged by clinical signs and symptoms, cell counts, and repeat cultures. Nonlocalizing physical examination and negative or nonspecific results of abdominal computed tomography do not rule out serious intra-abdominal disease. Immediate initiation of broad antibiotic coverage including for anaerobic infection is indicated when bowel pathology is suspected. Urgent surgical consultation, with active discussion and participation by the nephrologist, is advisable when visceral pathology is suspected and the patient is unstable or fails to improve rapidly.

Randomized, double-blind trial of antibiotic exit site cream for prevention of exit site infection in peritoneal dialysis patients

Infection is the Achilles heel of peritoneal dialysis. Exit site mupirocin prevents Staphylococcus aureus peritoneal dialysis (PD) infections but does not reduce Pseudomonas aeruginosa or other Gram-negative infections, which are associated with considerable morbidity and sometimes death. Patients from three centers (53% incident to PD and 47% prevalent) were randomized in a double-blinded manner to daily mupirocin or gentamicin cream to the catheter exit site. Infections were tracked prospectively by organism and expressed as episodes per dialysis-year at risk. A total of 133 patients were randomized, 67 to gentamicin and 66 to mupirocin cream. Catheter infection rates were 0.23/yr with gentamicin cream versus 0.54/yr with mupirocin (P = 0.005). Time to first catheter infection was longer using gentamicin (P = 0.03). There were no P. aeruginosa catheter infections using gentamicin compared with 0.11/yr using mupirocin (P < 0.003). S. aureus exit site infections were infrequent in both groups (0.06 and 0.08/yr; P = 0.44). Peritonitis rates were 0.34/yr versus 0.52/yr (P = 0.03), with a striking decrease in Gram-negative peritonitis (0.02/yr versus 0.15/yr; P = 0.003) using gentamicin compared with mupirocin cream, respectively. Gentamicin use was a significant predictor of lower peritonitis rates (relative risk, 0.52; 95% confidence interval, 0.29 to 0.93; P < 0.03), controlling for center and incident versus prevalent patients. Gentamicin cream applied daily to the peritoneal catheter exit site reduced P. aeruginosa and other Gram-negative catheter infections and reduced peritonitis by 35%, particularly Gram-negative organisms. Gentamicin cream was as effective as mupirocin in preventing S. aureus infections. Daily gentamicin cream at the exit site should be the prophylaxis of choice for PD patients.

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

BACKGROUND

Peritonitis due to Pseudomonas species is a serious complication in continuous ambulatory peritoneal dialysis (CAPD) patients. The clinical course of peritonitis due to Pseudomonas complicating CAPD remains unclear.

METHODS

All of the Pseudomonas species episodes of peritonitis in our dialysis unit were studied from 1995 to 1999. During this period, there were 859 episodes of peritonitis recorded, 113 of which were caused by the Pseudomonas species. Nine episodes were excluded because they were mixed growth. The remaining 104 episodes in 68 patients were reviewed.

RESULTS

The underlying renal diagnosis and prevalence of comorbid conditions of the 68 patients were similar to those found in our entire dialysis population. There was a history of antibiotic therapy within 30 days of the onset of peritonitis due to the Pseudomonas species in 69 episodes (66.3%). In 47 episodes (45.2%) there was a concomitant exit site infection. The overall primary response rate was 60.6% and the complete cure rate was 22.1%. The presence of exit site infection was associated with a lower primary response rate (22 in 47 vs. 41 in 57 episodes, P < 0.01) and a lower complete cure rate (5 in 47 vs. 18 in 57 episodes, P < 0.02). The episodes that had received recent antibiotic therapy had a significantly lower complete cure rate than the de novo cases (8 in 69 vs. 15 in 35 episodes, P < 0.001). Episodes receiving third-generation cephalosporin as part of the initial antibiotic regimen had a significantly higher primary response rate than the ones that initially received aminoglycoside (54 in 81 episodes vs. 8 in 22 episodes, P < 0.05), but their complete cure rates were similar. Twenty-four cases failed to respond to antibiotics and the Tenckhoff catheter was removed. The chance of returning to CAPD was higher when the Tenckhoff catheter was removed on day 10 than on day 15 (9 in 14 cases vs. 5 in 10 cases), although the result was not statistically significant. The Tenckhoff catheter was removed and replaced at another site simultaneously in another 14 cases after the effluent cleared up. None of these patients had a relapse of peritonitis within three months.

CONCLUSIONS

Recent antibiotic therapy is the major risk factor for peritonitis due to the Pseudomonas species. Exit site infection and recent antibiotic therapy are associated with poor therapeutic response to antibiotics. When the therapeutic response is suboptimal, early Tenckhoff catheter removal may help preserve the peritoneum for further peritoneal dialysis. Elective Tenckhoff catheter exchange after clearing up the peritoneal dialysis effluent may also reduce the likelihood of relapse. It is desirable to use third-generation cephalosporin in the initial antibiotic regimen for peritonitis treatment in localities with a high incidence of peritonitis due to the Pseudomonas species.

Outcomes of single organism peritonitis in peritoneal dialysis: gram negatives versus gram positives in the Network 9 Peritonitis Study

The use of the "peritonitis rate" in the management of patients undergoing peritoneal dialysis is assuming importance in comparing the prowess of facilities, care givers and new innovations. For this to be a meaningful outcome measure, the type of infection (causative pathogen) must have less clinical significance than the number of infections during a time interval. The natural history of Staphylococcus aureus, pseudomonas, and fungal peritonitis would not support that the outcome of an episode of peritonitis is independent of the causative pathogen. Could this concern be extended to other more frequently occurring pathogens? To address this, the Network 9 Peritonitis Study identified 530 episodes of single organism peritonitis caused by a gram positive organism and 136 episodes caused by a single non-pseudomonal gram negative (NPGN) pathogen. Coincidental soft tissue infections (exit site or tunnel) occurred equally in both groups. Outcomes of peritonitis were analyzed by organism classification and by presence or absence of a soft tissue infection. NPGN peritonitis was associated with significantly more frequent catheter loss, hospitalization, and technique failure and was less likely to resolve regardless of the presence or absence of a soft tissue infection. Hospitalization and death tended to occur more frequently with enterococcal peritonitis than with other gram positive peritonitis. The outcomes in the NPGN peritonitis group were significantly worse (resolution, catheter loss, hospitalization, technique failure) compared to coagulase negative staphylococcal or S. aureus peritonitis, regardless of the presence or absence of a coincidental soft tissue infection. Furthermore, for the first time, the poor outcomes of gram negative peritonitis are shown to be independent of pseudomonas or polymicrobial involvement or soft tissue infections. The gram negative organism appears to be the important factor. In addition, the outcome of peritonitis caused by S. aureus is worse than that of other staphylococci. Thus, it is clear that all peritonitis episodes cannot be considered equivalent in terms of outcome. The concept of peritonitis rate is only meaningful when specific organisms are considered.

Longitudinal follow-up of CA125 in peritoneal effluent

Mesothelial changes occur during peritoneal dialysis. CA125 provides a way to study the mesothelial cells in the in vivo situation. In the present study longitudinal changes of CA125 were analyzed. In addition, the appearance of CA125 in peritoneal effluent and day-to-day variability were studied. CA125 was measured in the effluent of five stable CAPD patients during four hour dwells with 1.36% glucose, with 3.86% glucose and with 7.5% icodextrin. In addition, CA125 was determined on six consecutive days in four hour effluents of three patients and appearance rates (AR) were calculated. Longitudinal follow-up was performed in 31 patients in whom three to seven yearly observations had been made. Linear appearance of CA125 was present in all dwells. No difference was found between the appearance rates of CA125 with 3.86% glucose, compared to either 1.36% glucose or icodextrin. Mean day-to-day coefficient of variation was 6.4% for CA125 AR, but a wide variation existed in stable CA125 values among patients (mean 22.1, range 2 to 48 U/ml). A negative trend with duration of CAPD was present in the longitudinal study. A mean decrease of 2.2% per year could be calculated, but substantial interindividual differences existed. Sudden decreases of CA125 AR were found in five patients. Possible causes were found in all of them and included a severe or recurrent peritonitis, and temporary cessation of peritoneal dialysis. In one patient a sudden decrease preceded the manifestation of peritoneal sclerosis. It can be concluded that CA125 can be used for the in vivo follow-up of the mesothelium in peritoneal dialysis patients. The appearance of CA125 in effluent is linear in time and not influenced by the initial lysis of mesothelial cells. A gradual loss of mesothelial cells is likely to occur, although interindividual variability is substantial. An acceleration of the process may be caused by severe peritonitis and perhaps by temporary cessation of peritoneal dialysis. A sudden decrease in CA125 may be an alarming sign for the development or manifestation of peritoneal sclerosis.

Xanthomonas maltophilia peritonitis in uremic patients receiving continuous ambulatory peritoneal dialysis

Xanthomonas maltophilia peritonitis has been only occasionally reported in patients receiving continuous ambulatory peritoneal dialysis. We present a series of six cases of peritonitis caused by such bacteria, accounting for 1.5% of all peritonitis episodes encountered in our renal unit over the past 5 years. Recent bacterial peritonitis treated with broad-spectrum antibiotics was the major risk factor, and the outcome was poor with medical treatment alone. Secondary peritonitis, especially fungal, was common and probably related to the prolonged course of antibiotics. All patients eventually required removal of the catheter, either because the effluent failed to clear up or because of secondary peritonitis. We suggest that X maltophilia peritonitis be treated with double antibiotics as soon as it is diagnosed. To prevent the development of superimposed infection after prolonged administration of antibiotics, the Tenckhoff catheter should be removed if the peritonitis fails to respond to a short course of antibiotics.

Risk factors for peritonitis in long-term peritoneal dialysis: the Network 9 peritonitis and catheter survival studies. Academic Subcommittee of the Steering Committee of the Network 9 Peritonitis and Catheter Survival Studies

To determine factors involved in peritoneal dialysis-associated peritonitis and catheter loss, all point prevalent peritoneal dialysis patients in Health Care Finance Administration (HCFA) end-stage renal disease (ESRD) Network 9 were followed throughout 1991 for peritonitis events and throughout 1991 to 1992 for catheter survival. Data were collected by questionnaires compiled by the dialysis facility and validated by network staff. Peritonitis was reported 1,168 times in 729 of the 1,930 patients. By gamma-Poisson regression, a significantly increased risk for peritonitis was observed for patients with previous peritonitis, black race, and those dialyzing with standard connectors or cyclers compared with disconnect systems. Decreased risks were observed for patients with longer ESRD experience and when prophylactic antibiotics were administered before catheter insertion. Postinsertion leakage, diabetes, visual problems, previous or current immunosuppression, and physical activity were not risk factors. Infection of any kind caused the removal of 68% of the 414 catheters lost. Patients with downward-directed tunnels were less likely to experience concomitant exit site/tunnel infections associated with peritonitis. Peritonitis episodes with Staphylococcus epidermidis-like organisms were more likely to resolve with a single course of antibiotics. Perhaps because of their higher infection rate, blacks were more likely than whites to use a disconnect system. In general, the outcome of peritonitis in blacks was similar to that in whites, except that blacks were less likely to be hospitalized and were less likely to die.

Peritoneal catheter exit-site and tunnel infections

Peritoneal catheter exit-site and tunnel infections may lead to peritonitis and catheter loss. Exit-site infections are diagnosed when there is pericatheter erythema and/or purulent drainage. Staphylococcus aureus is the most common cause of both exit-site and tunnel infections. S. aureus nasal carriage is an important risk factor for S. aureus catheter infections. Few other risk factors for catheter infections have been identified. Treatment of catheter infections consists of antibiotic therapy, often prolonged, as well as intensification of exit-site care. Refractory cases may resolve with revision of the tunnel and exit-site with removal of the superficial cuff, but some patients undergoing this procedure will develop peritonitis. Once peritonitis develops from a tunnel infection, the catheter should be replaced. Research on prevention of catheter infections has focused on three areas: antibiotic prophylaxis, exit-site care, and new catheter designs. Several antibiotic protocols, including intranasal mupirocin, cyclical oral rifampin, and exit-site mupirocin, are effective in decreasing S. aureus catheter infections and should be used more widely. New catheter designs may, in the future, prove to further diminish catheter infection and loss, but there are insufficient data at this time to show superiority of one catheter over another.