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

Exit Site Infection due to Mycobacterium chelonae in an Elderly Patient on Peritoneal Dialysis

Nontuberculous mycobacteria (NTM) are rarely isolated from peritoneal dialysis (PD)-associated catheter infections. However, NTM infection is usually difficult to treat and leads to catheter loss. Prompt diagnosis is essential for appropriate treatment. A 70-year-old Japanese man who had been on PD for 2 years and with a medical history of 2 episodes of exit site infections (ESIs) due to methicillin-resistant Staphylococcus aureus was admitted to the hospital due to suspected ESI recurrence. However, Gram staining of the pus revealed no gram-positive cocci. Instead, weakly stained gram-positive rods were observed after 7 days of incubation, which were also positive for acid-fast staining. Rapidly growing NTM Mycobacterium chelonae was isolated on day 14. Despite administering a combination antibiotic therapy, ESI could not be controlled, and catheter removal surgery was performed on day 21. Although PD was discontinued temporarily, the patient did not require hemodialysis, without any uremic symptoms. The catheter was reinserted on day 48, and PD was reinitiated on day 61. The patient was discharged on day 65. Antibiotic therapy was continued for 3 months after discharge, with no indications of recurrent infections observed. It is important to consider the risk of NTM infections in patients on PD. Acid-fast staining could be a key test for prompt diagnosis and provision of an appropriate treatment.

Peritoneal dialysis-associated catheter infection caused by Mycobacterium abscessus in an elderly patient who was successfully treated with catheter removal

An 89-year-old Japanese man on peritoneal dialysis (PD) was suspected of having a PD-associated catheter infection. He visited the hospital because of the discharge of pus from the exit site of his catheter. Gram staining of the pus showed Gram-positive bacilli, but these were acid-fast bacilli. The rapidly growing nontuberculous mycobacteria, Mycobacterium abscessus, was isolated. PD catheter removal and debridement were immediately performed. The patient received combination antibiotic therapy. His clinical course was good, but he required hemodialysis due to the discontinuation of PD. However, the patient and his family chose not to continue hemodialysis even when the symptoms of uremia appeared. Best supportive care was arranged by his primary care physician. M. abscessus is a rare causative organism for PD-associated catheter infections and is difficult to treat. In our case, a rapid and precise diagnosis was made using acid-fast staining and Mycobacterium culture. The risk of nontuberculous mycobacterial infections should be considered in patients on PD.

Antimicrobial agents for preventing peritonitis in peritoneal dialysis patients

BACKGROUND

Peritoneal dialysis (PD) is an important therapy for patients with end-stage kidney disease and is used in more than 200,000 such patients globally. However, its value is often limited by the development of infections such as peritonitis and exit-site and tunnel infections. Multiple strategies have been developed to reduce the risk of peritonitis including antibiotics, topical disinfectants to the exit site and antifungal agents. However, the effectiveness of these strategies has been variable and are based on a small number of randomised controlled trials (RCTs). The optimal preventive strategies to reduce the occurrence of peritonitis remain unclear.This is an update of a Cochrane review first published in 2004.

OBJECTIVES

To evaluate the benefits and harms of antimicrobial strategies used to prevent peritonitis in PD patients.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant's Specialised Register to 4 October 2016 through contact with the Information Specialist using search terms relevant to this review. Studies contained in the Specialised Register are identified through search strategies specifically designed for CENTRAL, MEDLINE, and EMBASE; handsearching conference proceedings; and searching the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

RCTs or quasi-RCTs in patients receiving chronic PD, which evaluated any antimicrobial agents used systemically or locally to prevent peritonitis or exit-site/tunnel infection were included.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed risk of bias and extracted data. Summary estimates of effect were obtained using a random-effects model, and results were expressed as risk ratio (RR) with 95% confidence intervals (CI).

MAIN RESULTS

Thirty-nine studies, randomising 4435 patients, were included. Twenty additional studies have been included in this update. The risk of bias domains were often unclear or high; risk of bias was judged to be low in 19 (49%) studies for random sequence generation, 12 (31%) studies for allocation concealment, 22 (56%) studies for incomplete outcome reporting, and in 12 (31%) studies for selective outcome reporting. Blinding of participants and personnel was considered to be at low risk of bias in 8 (21%) and 10 studies (26%) for blinding of outcome assessors. It should be noted that blinding of participants and personnel was not possible in many of the studies because of the nature of the intervention or control treatment.The use of oral or topical antibiotic compared with placebo/no treatment, had uncertain effects on the risk of exit-site/tunnel infection (3 studies, 191 patients, low quality evidence: RR 0.45, 95% CI 0.19 to 1.04) and the risk of peritonitis (5 studies, 395 patients, low quality evidence: RR 0.82, 95% CI 0.57 to 1.19).The use of nasal antibiotic compared with placebo/no treatment had uncertain effects on the risk of exit-site/tunnel infection (3 studies, 338 patients, low quality evidence: RR 1.34, 95% CI 0.62 to 2.87) and the risk of peritonitis (3 studies, 338 patients, low quality evidence: RR 0.94, 95% CI 0.67 to 1.31).Pre/perioperative intravenous vancomycin compared with no treatment may reduce the risk of early peritonitis (1 study, 177 patients, low quality evidence: RR 0.08, 95% CI 0.01 to 0.61) but has an uncertain effect on the risk of exit-site/tunnel infection (1 study, 177 patients, low quality evidence: RR 0.36, 95% CI 0.10 to 1.32).The use of topical disinfectant compared with standard care or other active treatment (antibiotic or other disinfectant) had uncertain effects on the risk of exit-site/tunnel infection (8 studies, 973 patients, low quality evidence, RR 1.00, 95% CI 0.75 to 1.33) and the risk of peritonitis (6 studies, 853 patients, low quality evidence: RR 0.83, 95% CI 0.65 to 1.06).Antifungal prophylaxis with oral nystatin/fluconazole compared with placebo/no treatment may reduce the risk of fungal peritonitis occurring after a patient has had an antibiotic course (2 studies, 817 patients, low quality evidence: RR 0.28, 95% CI 0.12 to 0.63).No intervention reduced the risk of catheter removal or replacement. Most of the available studies were small and of suboptimal quality. Only six studies enrolled 200 or more patients.

AUTHORS' CONCLUSIONS

In this update, we identified limited data from RCTs and quasi-RCTs which evaluated strategies to prevent peritonitis and exit-site/tunnel infections. This review demonstrates that pre/peri-operative intravenous vancomycin may reduce the risk of early peritonitis and that antifungal prophylaxis with oral nystatin or fluconazole reduces the risk of fungal peritonitis following an antibiotic course. However, no other antimicrobial interventions have proven efficacy. In particular, the use of nasal antibiotic to eradicate Staphylococcus aureus, had an uncertain effect on the risk of peritonitis and raises questions about the usefulness of this approach. Given the large number of patients on PD and the importance of peritonitis, the lack of adequately powered and high quality RCTs to inform decision making about strategies to prevent peritonitis is striking.

Comparison of topical mupirocin and gentamicin in the prevention of peritoneal dialysis-related infections: A systematic review and meta-analysis

BACKGROUND

Topical antibiotics have been shown to reduce exit-site infection and peritonitis. The aim of this study was to compare infection rates between mupirocin and gentamicin.

METHODS

Multiple comprehensive databases were searched systematically to include relevant randomized controlled trials and observational studies. Pooled risk ratios (RRs) and 95% confidence intervals were calculated for the incidences of exit-site infection and peritonitis.

RESULTS

Seven studies (mupirocin group n = 458, gentamicin group n = 448) were analyzed for exit-site infection. The risk of gram-positive exit-site infection was similar between the groups. Gram-negative exit-site infection rate was higher in the mupirocin group (RR = 2.125, P = 0.037). Six studies were assessed the peritonitis risk. There was no difference in the gram-positive and -negative peritonitis rate.

CONCLUSIONS

Topical use of gentamicin is associated with fewer exit-site infections caused by gram-negative organisms. Gentamicin has comparable efficacy to mupirocin for peritonitis and gram-positive exit-site infection.

Peritoneal dialysis practice in Australia and New Zealand: A call to sustain the action

This paper updates a previous 'Call to Action' paper (Nephrology 2011; 16: 19-29) that reviewed key outcome data for Australian and New Zealand peritoneal dialysis patients and made recommendations to improve care. Since its publication, peritonitis rates have improved significantly, although they have plateaued more recently. Peritoneal dialysis patient and technique survival in Australian and New Zealand have also improved, with a reduction in the proportion of technique failures attributed to 'social reasons'. Despite these improvements, technique survival rates overall remain lower than in many other parts of the world. This update includes additional practical recommendations based on published evidence and emerging initiatives to further improve outcomes.

Comparison of Topical Chlorhexidine and Mupirocin for the Prevention of Exit-Site Infection in Incident Peritoneal Dialysis Patients

♦ OBJECTIVE: Prevention of exit-site infection (ESI) is of paramount importance to peritoneal dialysis (PD) patients. The aim of this study was to evaluate the effectiveness of chlorhexidine in the prevention of ESI in incident PD patients compared with mupirocin. ♦ METHODS: This retrospective, pre-test/post-test observational study included all incident PD patients at Singapore General Hospital from 2012 to 2015. Patients received daily topical exit-site application of either mupirocin (2012 - 2013) or chlorhexidine (2014 - 2015) in addition to routine exit-site cleaning with 10% povidone-iodine. The primary outcome was ESI rate during the 2 time periods. Secondary outcomes were peritonitis rate, times to first ESI and peritonitis, hospitalization rate, and infection-related catheter removal. Event rates were analyzed using Poisson regression, and infection-free survival was estimated using Kaplan-Meier and Cox regression survival analyses. ♦ RESULTS: The study included 162 patients in the mupirocin period (follow-up 141.5 patient-years) and 175 patients in the chlorhexidine period (follow-up 136.9 patient-years). Compared with mupirocin-treated patients, chlorhexidine-treated patients experienced more frequent ESIs (0.22 vs 0.12 episodes/patient-year, p = 0.048), although this was no longer statistically significant following multivariable analysis (incidence rate ratio [IRR] 1.78, 95% confidence interval [CI] 0.98 - 3.26, p = 0.06). No significant differences were observed between the 2 groups with respect to time to first ESI (p = 0.10), peritonitis rate (p = 0.95), time to first peritonitis (p = 0.60), hospitalization rate (p = 0.21) or catheter removal rate (0.03 vs 0.04/patient-year, p = 0.56). ♦ CONCLUSIONS: Topical exit-site application of chlorhexidine cream was associated with a borderline significant, higher rate of ESI in incident PD patients compared with mupirocin cream.

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.

The Relationship Between Presentation and the Time of Initial Administration of Antibiotics With Outcomes of Peritonitis in Peritoneal Dialysis Patients: The PROMPT Study

Introduction

The impact of time to treatment on clinical outcome is an established precept in infectious disease but is not established in peritoneal dialysis–related peritonitis (PDRP).

Methods

In a prospective multicenter study of PDRP, symptom-to-contact time (SC), contact-to-treatment time (CT), defined as the time from health care presentation to initial antibiotic, and symptom-to-treatment time (ST) were determined.

Results

One hundred sixteen patients had 159 episodes of PDRP. Median SC for all episodes was 5.0 hours (first to third quartile [Q1–Q3]: 1.3–13.9); CT, 2.3 hours (Q1–Q3: 1.2–4.0); and ST, 9.0 hours (Q1–Q3: 4.7–25.3). Thirty-eight (23.9%) patient episodes (28 catheter removals and 10 deaths) met the primary composite outcome of PD failure at 30 days (PD-fail). The risk of PD-fail increased by 5.5% for each hour of delay of administration of antibiotics (odds ratio [OR] for CT: 1.055; 95% confidence interval [CI]: 1.005–1.109; P = 0.032). Neither SC (OR: 1.00; 95% CI: 0.99–1.01; P = 0.74) nor ST (OR: 1.00; 95% CI: 0.99–1.01; P = 0.48) was associated with PD-fail. In a multivariable analysis, only CT for presentation to a hospital-based facility compared with a community facility (OR: 1.068; 95% CI: 1.013–1.126; P = 0.015) and female sex (OR: 2.4; 95% CI: 1.1–5.4; P = 0.027) were independently associated with PD-fail. Each hour of delay in administering antibacterial therapy from the time of presentation to a hospital facility increased the risk of PD failure or death by 6.8%.

Discussion

Strategies targeted to expedited antibiotic treatment should be implemented to improve outcomes from PDRP.

Risk Factors for Early-Onset Peritonitis in Southern Chinese Peritoneal Dialysis Patients

♦ BACKGROUND: Early peritonitis was confirmed to be associated with a higher risk of early technique failure. However, literature concerning peritonitis within the first 3 months of peritoneal dialysis (PD) initiation is scarce. The present study was to investigate risk factors associated with early-onset peritonitis in PD patients. ♦ METHODS: In this retrospective observational cohort study, all incident PD patients from January 1, 2006, to December 31, 2013, were recruited and followed up until December 31, 2014. According to time-to-first episode of peritonitis, patients were divided into early-onset (≤ 3 months) peritonitis and late-onset (> 3 months) peritonitis. Baseline demographic, clinical, and laboratory data, as well as episodes of peritonitis, were collected. Risk factors associated with early-onset peritonitis were evaluated using logistic regression model. ♦ RESULTS: Of 1,690 patients on PD, 503 (29.8%) developed at least 1 episode of peritonitis and 118 (7.0%) patients presented the first episodes of peritonitis within the first 3 months. A multivariate logistic analysis showed that higher body mass index (BMI) (odds ratio [OR] 1.08, 95% confidence interval [CI] 1.01 - 1.15, p = 0.034), hypoalbuminemia (OR 1.75, 95% CI 1.11 - 2.78, p = 0.017), and catheter exit-site infection (OR 4.14, 95% CI 2.45 - 7.00, p < 0.001) were risk factors independently associated with early-onset peritonitis. Compared to those with late-onset, patients with early-onset peritonitis had a higher overall peritonitis rate (0.76 vs 0.38 per patient-year, p < 0.001) and worse technique survival (p < 0.001), while patient survival did not differ significantly between the 2 groups during the long-term follow-up (p > 0.05). ♦ CONCLUSIONS: Higher BMI, hypoalbuminemia, and catheter exit-site infection were the risk factors associated with early-onset peritonitis in PD patients.

Antimicrobial evaluation of quaternary ammonium polyethyleneimine nanoparticles against clinical isolates of pathogenic bacteria

Peritonitis is a disease caused by bacterial strains that have become increasingly resistant to many antibiotics. The development of alternative therapeutic compounds is the focus of extensive research, so novel nanoparticles (NPs) with activity against antibiotic-resistant bacteria should be developed. In this study, the antibacterial activity of quaternary ammonium polyethyleneimine (QA-PEI) NPs was evaluated against Streptococcus viridans, Stenotrophomonas maltophilia and Escherichia coli. To appraise the antibacterial activity, minimal inhibitory concentration (MIC), minimal bactericidal concentration and bactericidal assays were utilised with different concentrations (1.56-100 µg/ml) of QA-PEI NPs. Moreover, 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) and annexin V/propidium iodide toxicity assays were performed in cell cultures. MICs for S. maltophilia and E. coli isolates were 12.5 and 25 µg/ml, respectively, whereas the MIC for S. viridans was 100 µg/ml. Furthermore, the growth curve assays revealed that these QA-PEI NPs at a concentration of 12.5 µg/ml significantly inhibited bacterial growth for the bacterial isolates studied. On the other hand, QA-PEI NPs lacked significant toxicity for cells when used at concentrations up to 50 μg/ml for 48 h. The present findings reveal the potential therapeutic value of this QA-PEI NPs as alternative antibacterial agents for peritonitis, especially against Gram-negative bacteria.

A Case Report of Rash at Peritoneal Dialysis Exit Site

The International Society for Peritoneal Dialysis recommends the regular application of topical antibiotic-containing preparations in addition to a routine exit site care to reduce the risk of exit site infection (ESI). Among these prophylactic antimicrobial preparations, topical gentamicin is one of the widely used and effective antibiotics for prevention of ESI and peritonitis in peritoneal dialysis (PD) patients. Overall, topical gentamicin is well tolerated; however, its use can be associated with the development of allergic contact dermatitis (ACD). We describe a first reported case of PD catheter exit site contact ACD due to topical gentamicin mimicking ESI. The patient in this report developed worsening violaceous in color and pruritic rash surrounding the PD catheter exit site that appeared 3 weeks after the initiation of gentamicin cream. The association between development of rash and initiation of topical gentamicin led to a suspicion of local reaction to gentamicin rather than ESI. Skin biopsy confirmed ACD. Discontinuation of the provoking agent and subsequent treatment with topical hydrocortisone application led to a resolution of the exit site rash. Any rash at a PD catheter exit site should be considered infectious until proven otherwise. However, it is important to be aware of noninfectious etiologies of exit site rashes as the treatment of these 2 conditions differs.

Peritoneal Dialysis in Western Countries

BACKGROUND

Peritoneal dialysis (PD) for the treatment of end-stage renal failure was introduced in the 1960s. Nowadays it has evolved to an established therapy that is complementary to hemodialysis (HD), representing 11% of all patients treated worldwide with dialysis. Despite good clinical outcomes and similar results in patient survival between PD and HD, the penetration of PD is decreasing in the Western world.

SUMMARY

First the major events in the history of the development of PD are described. Then important insights into the physiology of peritoneal transport are discussed and linked to the changes in time observed in biopsies of the peritoneal membrane. Furthermore, the developments in peritoneal access, more biocompatible dialysate solutions, automated PD at home, the establishment of parameters for dialysis adequacy and strategies to prevent infectious complications are mentioned. Finally non-medical issues responsible for the declining penetration in the Western world are analyzed.

KEY MESSAGES

Only after introduction of the concept of continuous ambulatory PD by Moncrief and Popovich has this treatment evolved in time to a renal replacement therapy. Of all structures present in the peritoneal membrane, the capillary endothelium offers the rate-limiting hindrance for solute and water transport for the diffusive and convective transport of solutes and osmosis. The functional and anatomical changes in the peritoneal membrane in time can be monitored by the peritoneal equilibrium test. Peritonitis incidence decreased by introduction of the Y-set and prophylaxis using mupirocin on the exit site. The decrease in the proportion of patients treated with PD in the Western world can be explained by non-medical issues such as inadequate predialysis patient education, physician experience and training, ease of HD initiation, overcapacity of in-center HD, lack of adequate infrastructure for PD treatment, costs and reimbursement issues of the treatment.

FACTS FROM EAST AND WEST

(1) PD is cheaper than HD and provides a better quality of life worldwide, but its prevalence is significantly lower than that of HD in all countries, with the exception of Hong Kong. Allowing reimbursement of PD but not HD has permitted to increase the use of PD over HD in many Asian countries like Hong Kong, Vietnam, Taiwan, Thailand, as well as in New Zealand and Australia over the last years. In the Western world, however, HD is still promoted, and the proportion of patients treated with PD decreases. Japan remains an exception in Asia where PD penetration is very low. Lack of adequate education of practitioners and information of patients might as well be reasons for the low penetration of PD in both the East and West. (2) Patient survival of PD varies between and within countries but is globally similar to HD. (3) Peritonitis remains the main cause of morbidity in PD patients. South Asian countries face specific issues such as high tuberculosis and mycobacterial infections, which are rare in developed Asian and Western countries. The infection rate is affected by climatic and socio-economic factors and is higher in hot, humid and rural areas. (4) Nevertheless, the promotion of a PD-first policy might be beneficial particularly for remote populations in emerging countries where the end-stage renal disease rate is increasing dramatically.

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.

Peritoneal dialysis-related peritonitis: towards improving evidence, practices, and outcomes

Peritonitis is a common serious complication of peritoneal dialysis that results in considerable morbidity, mortality, and health care costs. It also significantly limits the use of this important dialysis modality. Despite its importance as a patient safety issue, peritonitis practices and outcomes vary markedly and unacceptably among different centers, regions, and countries. This article reviews peritonitis risk factors, diagnosis, treatment, and prevention, particularly focusing on potential drivers of variable practices and outcomes, controversial or unresolved areas, and promising avenues warranting further research. Potential strategies for augmenting the existing limited evidence base and reducing the gap between evidence-based best practice and actual practice also are discussed.

Prevention of peritonitis in peritoneal dialysis

Reducing the frequency of peritonitis for patients undergoing peritoneal dialysis (PD) continues to be a challenge. This review focuses on recent updates in catheter care and other patient factors that influence infection rates. An experienced nursing staff plays an important role in teaching proper PD technique to new patients, but nursing staff must be cognizant of each patient's unique educational needs. Over time, many patients become less adherent to proper dialysis technique, such as washing hands or wearing a mask. This behavior is associated with higher risk of peritonitis and is modifiable with re-training. Prophylactic antibiotics before PD catheter placement can decrease the infection risk immediately after catheter placement. In addition, some studies suggest that prophylaxis against fungal superinfection after antibiotic exposure is effective in reducing fungal peritonitis, although larger randomized studies are needed before this practice can be recommended for all patients. Over time, exit site and nasal colonization with pathogenic organisms can lead to exit-site infections and peritonitis. For patients with Staphylococcus aureus colonization, exit-site prophylaxis with either mupirocin or gentamicin cream reduces clinical infection with this organism. Although there are limited data for support, antibiotic prophylaxis before gastrointestinal, gynecologic, or dental procedures may also help reduce the risk of peritonitis.

The risk of peritonitis after an exit site infection: a time-matched, case-control study

BACKGROUND

Exit site infections (ESIs) have been previously associated with the development of peritonitis; however, the evidence to support this association is limited. We conducted a time-matched, case-control study to determine the association between ESIs and subsequent peritonitis.

METHODS

The cohort comprised 962 incident adult peritoneal dialysis (PD) patients from January 2000 to December 2009. Patients with an ESI were matched to those with no ESI based on the duration of PD. The subsequent risk of peritonitis was determined using Cox models and conditional logistic regression.

RESULTS

During the study period, there were a total of 1002 ESI and 1228 peritonitis episodes among 962 individuals. The time to subsequent peritonitis was shorter in individuals who had at least one ESI [hazard ratio (HR) 1.59; 95% confidence interval (CI) 1.22-2.07, P<0.001]. The risk of peritonitis post-ESI was increased for all Gram-positive infections [adjusted hazard ratio (aHR) 1.75; 95% CI 1.25-2.43], and for the subtypes of coagulase-negative Staphylococcus (CNS) and S. aureus, but not for Gram-negative or culture-negative infections. These findings were similar when examining the odds of subsequent peritonitis within prespecified time intervals of the ESI through conditional logistic regression.

CONCLUSIONS

The risk of peritonitis after ESI is increased, particularly with S. aureus and CNS, despite appropriate antibiotic treatment of the ESI.

Perforative peritonitis caused by appendicitis in a patient on peritoneal dialysis

A 46-year-old man on peritoneal dialysis (PD) was hospitalized due to suspicious PD-related peritonitis. Because the patient's abdominal pain was unimproved by conventional antibiotics and multiple bacteria were identified in a smear-sample of PD fluid, endogenous peritonitis was suspected. Perforated appendicitis was finally diagnosed under exploratory laparotomy. In this patient, perforated appendicitis was difficult to diagnose due to the attenuated clinical symptoms and inconclusive results of abdominal computed tomography (CT), even though the positive predictive value of CT is >95% in non-PD patients. Quickly deciding to perform exploratory laparotomy in patients suspected of having endogenous peritonitis is thus important, even when the origin has not been clarified.