Serratia marcescens Peritonitis in a Diabetic Patient Receiving Continuous Ambulatory Peritoneal Dialysis

We report a case of Serratia marcescens peritonitis in a 45-year-old man with insulin-dependent diabetes mellitus undergoing continuous ambulatory peritoneal dialysis (CAPD). The patient presented with abdominal pain and cloudy dialysate. Empiric antibiotic therapy was initiated intraperitoneally with cefazolin and ceftazidime for 5 days. Cultures of the dialysate revealed S. marcescens, and the treatment was subsequently changed to gentamicin and ceftazidime. Oral ciprofloxacin was also added. The patient's abdominal pain and the dialysate white blood cell (WBC) count, however, did not improve. The indwelling CAPD catheter was therefore removed. This is an unusual case report in the Korean literature of S. marcescens peritonitis in a patient receiving CAPD.

Effects of age and diabetes mellitus on clinical outcomes in patients with peritoneal dialysis-related peritonitis

BACKGROUND

Peritoneal dialysis (PD)-related peritonitis is the most common complication and the leading cause of technique failure for patients on PD therapy. The aim of this study was to review the episodes and outcomes of PD-related peritonitis, with special reference to the effects of age and diabetes status.

METHODS

The study comprised 204 consecutive peritonitis episodes between January 2001 and June 2011 from our registry database. Factors associated with treatment failure and mortality were analyzed with multi-variable logistic regression modeling.

RESULTS

The overall peritonitis rate was one episode per 65 patient-months or 0.187 episodes/patient-year. Older patients had lower probability of remaining free of peritonitis (log rank, p<0.001). Elderly patients and diabetic subjects had a higher risk of peritonitis-related dropout. Age (odds ratio [OR], 1.37; p=0.041), diabetes mellitus (OR, 3.64; p=0.005), and gram-negative peritonitis (OR, 3.55; p=0.011) were independent determinants of catheter removal. Age (OR, 1.93; p=0.026) and diabetes (OR, 5.98; p=0.015) were the only predictors of death from peritonitis.

CONCLUSIONS

Old age and diabetes mellitus are two major risk factors for adverse outcomes of PD-related peritonitis. Although they are not contraindications to PD, our results suggest that these patients need meticulous care when peritonitis occurs.

Outcomes of peritonitis in children on peritoneal dialysis: a 25-year experience at Severance Hospital

PURPOSE

Relatively little is known on the microbiology, risk factors and outcomes of peritoneal dialysis (PD)-associated peritonitis in Korean children. We performed this study in order to evaluate the incidence, treatment and clinical outcomes of peritonitis in pediatric PD patients at Severance Hospital.

MATERIALS AND METHODS

We analyzed data from 57 PD patients younger than 18 years during the period between June 1, 1986 and December 31, 2011. The collected data included gender, age at commencement of PD, age at peritonitis, incidence of peritonitis, underlying causes of end stage renal disease, microbiology of peritonitis episodes, antibiotics sensitivity, modality and outcomes of PD.

RESULTS

We found 56 episodes of peritonitis in 23 of the 57 PD patients (0.43 episodes/patient-year). Gram-positive bacteria were the most commonly isolated organisms (40 episodes, 71.4%). Peritonitis developed in 17 patients during the first 6 months following initiation of PD (73.9%). Peritonitis episodes rarely resulted in relapse or the need for permanent hemodialysis and no patient deaths were directly attributable to peritonitis. Antibiotic regimens included cefazolin+tobramycin from the years of 1986 to 2000 and cefazolin+ ceftazidime from the years of 2001 to 2011. While antibiotic therapy was successful in 48 episodes (85.7%), the treatment was ineffective in 8 episodes (14.3%). The rate of continuous ambulatory PD (CAPD) peritonitis was statistically higher than that of automated PD (APD) (p=0.025).

CONCLUSION

Peritonitis was an important complication of PD therapy and we observed a higher incidence of PD peritonitis in patients with CAPD when compared to APD.

Quality of life in chronic haemodialysis and peritoneal dialysis patients in Turkey and related factors

Turkey is the fifth country in Europe with regard to the number of patients receiving haemodialysis (HD). However, only a limited number of studies have comparatively investigated the factors that affect quality of life in haemodialysis and peritoneal dialysis (PD) patients in Turkey. The purpose of the study was to investigate the factors that affect quality of life in haemodialysis and peritoneal dialysis patients, as well as providing a comparison of quality of life between these groups. In this cross-sectional study, Quality of Life Scale and a data form was completed by 300 dialysis patients who received treatment at five hospital-based dialysis units in Istanbul, Turkey. The data were evaluated using arithmetic mean values, standard deviations, minimums, maximums, percentages, independent groups t-tests, Spearman correlation analyses and one-way variance analyses. The quality of life values in peritoneal dialysis patients were found to be higher than those of haemodialysis patients (P < 0.05). It was concluded that the quality of life in chronic dialysis patients was affected by various factors.

Clinical characteristics and outcomes of peritoneal dialysis-related peritonitis with different trends of change in effluent white cell count: a longitudinal study

BACKGROUND

Effluent white cell count (WCC) is among the important prognostic factors for peritonitis outcome, but its trend has never been studied. We aimed to explore the clinical characteristics and outcomes of peritonitis episodes having different trends in effluent WCC change in the first 5 days.

METHODS

For each peritonitis episode, we examined the patient's demographic and biochemical data, serial effluent WCC, and organisms cultured. Peritonitis-associated death and transfer to hemodialysis were defined as treatment failure.

RESULTS

Based on the trend of effluent WCC in the first 5 days, we divided 190 peritonitis episodes into group A (WCC persistently declined), group B (WCC declined after a transient increase), group C (WCC increased after a transient decline), and group D (WCC persistently increased). In group A, peritonitis was caused mostly by gram-positive organisms, and effluent WCC declined the most quickly, leading to a good prognosis. Although the elevation of effluent WCC was prolonged in group B, and the infections were, compared with those in group A, more often caused by gram-negative organisms, outcomes were not worse. In group C, the effluent WCC was more likely to be higher than 100/μL on day 5, and the infection was, compared with those in groups A and B, less likely to be caused by gram-positive organisms. Accordingly, membership in group C independently predicted the worst outcome of peritonitis even adjusted for age, sex, and causative organism.

CONCLUSIONS

Different trends of change in effluent WCC during the early stage of peritonitis represent different clinical patterns and outcomes. Further investigation for optimizing outcomes is required.

Bacteria on catheters in patients undergoing peritoneal dialysis

BACKGROUND

Peritonitis is the leading cause of morbidity for peritoneal dialysis (PD) patients, and microbial biofilms have previously been identified on catheters from infected patients. However, few studies of catheters from patients without clinical signs of infection have been undertaken. The aim of the present study was to investigate the extent to which bacteria are present on catheters from PD patients with no symptoms of infection.

METHODS

Microbiologic culturing under aerobic and anaerobic conditions and confocal laser scanning microscopy were used to determine the distribution of bacteria on PD catheters from 15 patients without clinical signs of infection and on catheters from 2 infected patients. The 16S rRNA gene sequencing technique was used to identify cultured bacteria.

RESULTS

Bacteria were detected on 12 of the 15 catheters from patients without signs of infection and on the 2 catheters from infected patients. Single-species and mixed-microbial communities containing up to 5 species were present on both the inside and the outside along the whole length of the colonized catheters. The bacterial species most commonly found were the skin commensals Staphylococcus epidermidis and Propionibacterium acnes, followed by S. warneri and S. lugdunensis. The strains of these micro-organisms, particularly those of S. epidermidis, varied in phenotype with respect to their tolerance of the major classes of antibiotics.

CONCLUSIONS

Bacteria were common on catheters from patients without symptoms of infection. Up to 4 different bacterial species were found in close association and may represent a risk factor for the future development of peritonitis in patients hosting such micro-organisms.

Clinical characteristics and outcomes of "silent" and "non-silent" peritonitis in patients on peritoneal dialysis

OBJECTIVES

We compared the clinical characteristics and outcomes of "silent" peritonitis (meaning episodes without fever and abdominal pain) and "non-silent" peritonitis in patients on peritoneal dialysis (PD).

METHODS

Our cohort study collected data about all peritonitis episodes occurring between January 2008 and April 2010. Disease severity score, demographics, and biochemistry and nutrition data were recorded at baseline. Effluent cell counts were examined at regular intervals, and the organisms cultured were examined. Treatment failure was defined as peritonitis-associated death or transfer to hemodialysis.

RESULTS

Of 248 episodes of peritonitis occurring in 161 PD patients, 20.9% led to treatment failure. Of the 248 episodes, 51 (20.6%) were not accompanied by fever and abdominal pain. Patients with these silent peritonitis episodes tended to be older (p = 0.003). The baseline values for body mass index, triglycerides, and daily energy intake were significantly lower before silent peritonitis episodes than before non-silent episodes (p = 0.01, 0.003, and 0.001 respectively). Although silent peritonitis episodes were more often culture-negative and less often caused by gram-negative organisms, and although they presented with low effluent white cell counts on days 1 and 3, the risk for treatment failure in those episodes was not lower (adjusted odds ratio: 1.33; 95% confidence interval: 0.75 to 2.36; p = 0.33).

CONCLUSIONS

Silent peritonitis is not a rare phenomenon, especially in older patients on PD. Although these episodes were more often culture-negative, silent presentation was not associated with a better outcome.

Successful treatment of extensively drug-resistant Acinetobacter baumannii peritoneal dialysis peritonitis with intraperitoneal polymyxin B and ampicillin-sulbactam

OBJECTIVE

To describe a case of extensively drug-resistant (XDR) Acinetobacter baumannii peritoneal dialysis (PD)-associated peritonitis successfully treated with combination antibiotics, including intraperitoneal polymyxin B, with retention of the catheter.

CASE SUMMARY

A 54-year-old woman with end-stage renal disease receiving chronic PD and recent antibiotic and hospital exposure presented with abdominal pain, nausea, and vomiting. She was found to have XDR A. baumannii PD peritonitis. Treatment was initiated with intravenous and intraperitoneal ampicillin-sulbactam, followed by the addition of intraperitoneal polymyxin B based on susceptibilities. The patient recovered without the need for catheter removal or switch to hemodialysis.

DISCUSSION

The frequency of XDR A. baumannii as a nosocomial pathogen is increasing, and polymyxins are being used more often as part of combination therapy for infections caused by this organism. Neither XDR A. baumannii PD peritonitis nor the use of intraperitoneal polymyxin B has been well described. In our patient, intraperitoneal dosing of polymyxin B was determined based on limited published pharmacokinetic and pharmacodynamic data.

CONCLUSIONS

A case of XDR A. baumannii PD peritonitis was successfully treated with combination antibiotic therapy, including intraperitoneal polymyxin B, without major complications.

Peritoneal dialysis-related peritonitis due to Staphylococcus aureus: a single-center experience over 15 years

Peritonitis caused by Staphylococcus aureus is a serious complication of peritoneal dialysis (PD), which is associated with poor outcome and high PD failure rates. We reviewed the records of 62 S. aureus peritonitis episodes that occurred between 1996 and 2010 in the dialysis unit of a single university hospital and evaluated the host and bacterial factors influencing peritonitis outcome. Peritonitis incidence was calculated for three subsequent 5-year periods and compared using a Poisson regression model. The production of biofilm, enzymes, and toxins was evaluated. Oxacillin resistance was evaluated based on minimum inhibitory concentration and presence of the mecA gene. Logistic regression was used for the analysis of demographic, clinical, and microbiological factors influencing peritonitis outcome. Resolution and death rates were compared with 117 contemporary coagulase-negative staphylococcus (CoNS) episodes. The incidence of S. aureus peritonitis declined significantly over time from 0.13 in 1996–2000 to 0.04 episodes/patient/year in 2006–2010 (p = 0.03). The oxacillin resistance rate was 11.3%. Toxin and enzyme production was expressive, except for enterotoxin D. Biofilm production was positive in 88.7% of strains. The presence of the mecA gene was associated with a higher frequency of fever and abdominal pain. The logistic regression model showed that diabetes mellitus (p = 0.009) and β-hemolysin production (p = 0.006) were independent predictors of non-resolution of infection. The probability of resolution was higher among patients aged 41 to 60 years than among those >60 years (p = 0.02). A trend to higher death rate was observed for S. aureus episodes (9.7%) compared to CoNS episodes (2.5%), (p = 0.08), whereas resolution rates were similar. Despite the decline in incidence, S. aureus peritonitis remains a serious complication of PD that is associated with a high death rate. The outcome of this infection is negatively influenced by host factors such as age and diabetes mellitus. In addition, β-hemolysin production is predictive of non-resolution of infection, suggesting a pathogenic role of this factor in PD-related S. aureus peritonitis.

Peritoneal dialysis-associated peritonitis rates and outcomes in a national cohort are not improving in the post-millennium (2000-2007)

BACKGROUND

Peritoneal dialysis (PD)-related peritonitis remains the leading cause of technique failure and a significant cause of morbidity among PD patients. Rates in the literature vary, reflecting differences in study design and in populations. The objective of the present study was to determine peritonitis incidence and outcomes in Scotland and to compare them with national guidelines.

METHODS

All 10 adult renal units in Scotland prospectively collect data relating to peritonitis for all PD patients in Scotland. Complete audit data between 1 January 2000 and 31 December 2007 were analyzed for the study.

RESULTS

The 1918 peritonitis episodes in 38 106 PD treatment months yielded a national rate of 1 episode every 19.9 months. The UK Renal Association standard was met every year, but is not consistently improving. The median peritonitis-free survival was 526 days (95% confidence interval: 463 to 589 days). The spectrum of causative organisms reflected those in previous reports, with a culture-negative rate of 19.4%. Nationally, the cure rate was 74.6%, the refractory rate was 22.6%, and the death rate was 2.8%. Outcome varied by organism. Recurrences represented 9.3% of episodes, and technique failure occurred in 14.9%. The peritonitis rate was higher for continuous ambulatory PD patients than for automated PD patients (1 episode every 17.6 months vs 1 episode every 22.3 months, p < 0.001, relative risk: 1.27). There were significant differences between renal units.

CONCLUSIONS

This large national PD cohort met targets for peritonitis rates every year during the 8 years covered by the present report, but showed no consistent trend for improvement. Peritonitis remains the main cause of technique failure in Scotland. Peritonitis rates varied widely between the units, which suggests that we should look to the units and countries with lower peritonitis rates to see if we can adopt successful elements of their practice before resigning ourselves to our ongoing peritonitis burden.

Human neutrophil clearance of bacterial pathogens triggers anti-microbial γδ T cell responses in early infection

Human blood Vγ9/Vδ2 T cells, monocytes and neutrophils share a responsiveness toward inflammatory chemokines and are rapidly recruited to sites of infection. Studying their interaction in vitro and relating these findings to in vivo observations in patients may therefore provide crucial insight into inflammatory events. Our present data demonstrate that Vγ9/Vδ2 T cells provide potent survival signals resulting in neutrophil activation and the release of the neutrophil chemoattractant CXCL8 (IL-8). In turn, Vγ9/Vδ2 T cells readily respond to neutrophils harboring phagocytosed bacteria, as evidenced by expression of CD69, interferon (IFN)-γ and tumor necrosis factor (TNF)-α. This response is dependent on the ability of these bacteria to produce the microbial metabolite (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMB-PP), requires cell-cell contact of Vγ9/Vδ2 T cells with accessory monocytes through lymphocyte function-associated antigen-1 (LFA-1), and results in a TNF-α dependent proliferation of Vγ9/Vδ2 T cells. The antibiotic fosmidomycin, which targets the HMB-PP biosynthesis pathway, not only has a direct antibacterial effect on most HMB-PP producing bacteria but also possesses rapid anti-inflammatory properties by inhibiting γδ T cell responses in vitro. Patients with acute peritoneal-dialysis (PD)-associated bacterial peritonitis – characterized by an excessive influx of neutrophils and monocytes into the peritoneal cavity – show a selective activation of local Vγ9/Vδ2 T cells by HMB-PP producing but not by HMB-PP deficient bacterial pathogens. The γδ T cell-driven perpetuation of inflammatory responses during acute peritonitis is associated with elevated peritoneal levels of γδ T cells and TNF-α and detrimental clinical outcomes in infections caused by HMB-PP positive microorganisms. Taken together, our findings indicate a direct link between invading pathogens, neutrophils, monocytes and microbe-responsive γδ T cells in early infection and suggest novel diagnostic and therapeutic approaches.

The immune system of all jawed vertebrates harbors three distinct lymphocyte populations – αβ T cells, γδ T cells and B cells – yet only higher primates including humans possess so-called Vγ9/Vδ2 T cells, an enigmatic γδ T cell subset that uniformly responds to the majority of bacterial pathogens. For reasons that are not understood, this responsiveness is absent in all other animals although they too are constantly exposed to a plethora of potentially harmful micro-organisms. We here investigated how Vγ9/Vδ2 T cells respond to live microbes by mimicking physiological conditions in acute disease. Our experiments demonstrate that Vγ9/Vδ2 T cells recognize a small common molecule released when invading bacteria become ingested and killed by other white blood cells. The stimulation of Vγ9/Vδ2 T cells at the site of infection amplifies the inflammatory response and has important consequences for pathogen clearance and the development of microbe-specific immunity. However, if triggered at the wrong time or the wrong place, this rapid reaction toward bacteria may also lead to inflammation-related damage. These findings improve our insight into the complex cellular interactions in early infection, identify novel biomarkers of diagnostic and predictive value and highlight new avenues for therapeutic intervention.

Pharmacokinetics and pharmacodynamics of intravenous daptomycin during continuous ambulatory peritoneal dialysis

BACKGROUND AND OBJECTIVES

This study sought to (1) characterize the pharmacokinetic (PK) profile of intravenous (i.v.) daptomycin among patients receiving continuous ambulatory peritoneal dialysis (CAPD); (2) identify optimal i.v. CAPD dosing schemes; and (3) determine extent of daptomycin penetration into the peritoneal space after i.v. administration.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A PK study was conducted among eight CAPD patients. Population PK modeling and Monte Carlo simulation (MCS) were used to identify CAPD dosing schemes providing efficacy and toxicity plasma profiles comparable with those obtained from MCS using the daptomycin population PK model derived from patients in the Staphylococcus aureus bacteremia-infective endocarditis (SAB-IE) study. The primary efficacy exposure target was the area under the curve (AUC). For toxicity, the goal was to identify CAPD dosing schemes that minimized plasma trough concentrations in excess of 24.3 mg/L. Finally, peritoneal cavity penetration was determined.

RESULTS

Administration of i.v. daptomycin 4 or 6 mg/kg, depending on indication, every 48 h was identified as the optimal CAPD dosing scheme. This regimen provided cumulative (AUC(0-48)) and daily partitioned (AUC(0-24 h) and AUC(24-48 h)) plasma AUC values similar to the SAB-IE or "typical patient" simulations. In addition, the proportion of patients likely to experience an elevated trough concentration in excess of 24.3 mg/L was similar between every 48 h CAPD dosing and the referent group. Penetration into the peritoneal cavity was 6% of plasma.

CONCLUSIONS

Daptomycin 4 or 6 mg/kg, on the basis of indication, i.v. every 48 h was found to be the optimal i.v. CAPD dosing scheme.

First case of CAPD-related peritonitis caused by Morganella morganii

Morganella morganii, a gram-negative bacillus, is a rare cause of peritonitis. In this article we report a 55-year-old female patient with peritonitis due to Morganella morganii who was receiving continuous ambulatory peritoneal dialysis (CAPD).

Comparative analysis of two-piece extended peritoneal dialysis catheters with remote exit-site locations and conventional abdominal catheters

BACKGROUND

An alternative peritoneal catheter exit-site location is sometimes needed in patients with obesity, floppy skin folds, intestinal stomas, urinary and fecal incontinence, and chronic yeast intertrigo. Two-piece extended catheters permit remote exit-site locations away from problematic abdominal conditions.

OBJECTIVE

The effect on clinical outcomes by remotely locating catheter exit sites to the upper abdomen or chest was compared to conventional lower abdominal sites.

METHODS

In a nonrandomized design, peritoneal access was established with 158 extended catheters and 270 conventional catheters based upon body habitus and special clinical needs. Prospective data collection included patient demographics, infectious and mechanical complications, and catheter survival.

RESULTS

Kaplan-Meier survival time until first exit-site infection was longer for extended catheters (p = 0.03). Poisson regression showed no difference in exit site, subcutaneous tunnel, and peritonitis infection rates; however, the proportion of catheters lost during peritonitis episodes was significantly greater for extended catheters (p = 0.007) and appeared to be due primarily to coagulase-negative staphylococcus organisms. Poisson regression showed interactions of body mass index (BMI) and diabetic status in determining catheter loss from peritonitis for both catheter types (p = 0.02). Extended catheter patients had higher BMI and diabetes prevalence (p < 0.0001). Overall extended catheter survival at 1, 2, and 3 years (92%, 80%, 71%) trended lower than conventional devices (93%, 87%, 80%; p = 0.0505).

CONCLUSIONS

Extended catheters enable peritoneal access for patients in whom conventional catheter placement would be difficult or impossible. Certain patient and extended-catheter characteristics may contribute to loss from peritonitis.

Correlation of periscreen strip results and white cell count in peritoneal dialysis peritonitis

INTRODUCTION

Monitoring of peritoneal dialysis (PD) peritonitis can be difficult for visually impaired patients. PeriScreen strips measure leukocyte esterase activity and this might be a useful objective test that can be performed by patients at home.

METHODS

A prospective study of 138 episodes of peritonitis was undertaken. Effluent samples were analysed for white cell count (WCC) and PeriScreen score on days 3 and 5. Co-morbidity data were collated from these patients.

RESULTS

Effluent WCC and PeriScreen results were found to correlate with the gold standard assessment of microbiology WCC count. A positive PeriScreen result on day 5 predicted that the episode of peritonitis would relapse after treatment with a sensitivity of 80% but with a poor specificity of 45%. Patients who cleared or relapsed their peritonitis could not be differentiated based on their burden of co-morbidity, Karnofsky scores, age, dialysis vintage or infective organism.

CONCLUSION

PeriScreen strip analysis correlated with microscopic WCC of PD. However, analysis of PD effluent on day 5 of treatment is not a good test to risk stratify patients for relapsing peritonitis.

Encapsulating peritoneal sclerosis: a single-center experience and review of the literature

Encapsulating peritoneal sclerosis (EPS) is a serious and often fatal complication of long-term PD with severe malnutrition and poor prognosis. It causes progressive obstruction and encapsulation of the bowel. This retrospective study reviews our experience and that reviewed in the literature concerning EPS. It refers to a total of 1966 patients treated with chronic PD between 1974 and 2008. Twenty one of them (1.1%) developed EPS, with the incidence increasing with the duration of PD. Mean age of our patients with EPS was 43, ranging from 18 to 71 years, 8 were men and 13 women with a mean body mass index (BMI) of 21.6 kg/m(2). Only one patient had Type II diabetes, 15 patients had glomerular disease, and six of these 15 had an autoimmune disease such as Wegener's granulomatosis and SLE. Thirteen patients developed EPS while on PD, 7 within 2 years after transfer to HD, and only one after renal transplantation. However, 7 patients had a previous renal transplant before returning to PD and subsequently developing EPS. Interestingly, we did not observe more episodes of EPS after transplantation. In the patients who developed EPS, the peritonitis rate over the period of observation was 1/15.6 pt-months and was due to Staphylococcus aureus, coagulase-negative staphylococcus, Pseudomonas and fungi. A history of peritonitis was not a prerequisite for developing EPS, since one patient had no episodes of peritonitis and 4 had just one previous episode. Fifteen patients presented with peritonitis within 4 months before the diagnosis of EPS with particularly virulent micro-organisms such as S. aureus, Candida, Pseudomonas, Corynebacterium, and Peptostreptococcus. Eleven patients were treated with hypertonic dextrose solutions (4.25 g/dl of dextrose) and seven with icodextrin, indirectly suggesting problems with ultrafiltration. Nine of 21 patients were on beta-blockers. The diagnosis of EPS was made either surgically or radiologically with signs of small bowel obstruction in combination with severe malnutrition. Eleven of our patients (52%) had evidence of small bowel obstruction and 14 patients required total parenteral nutrition (TPN). Tamoxifen (10-20 mg daily) was started in 6 patients, 4 of whom are alive and 2 deceased 3 and 5 years after EPS was diagnosed. Of the 12 patients who were not given tamoxifen, 2 are alive and 10 died. No side effects of tamoxifen were reported. Only 7 of our patients (33%) died during the first year after the diagnosis of EPS. Currently, 4 patients are on HD and 3 have had a renal transplant. Six patients of the fourteen who underwent surgery (42.8%) died within the first 6 months after operation and five died after an average of 6.6 years, mostly due to cardiovascular causes, three are still alive. As EPS becomes more prevalent with longer duration of PD, large multicenter prospective studies are needed to establish its incidence and identify risk factors, therapeutic approach, and prognosis.

Positive dialysate gram stain predicts outcome of empirical antibiotic therapy for peritoneal dialysis-associated peritonitis

Empirical antibiotic treatment with a first-generation cephalosporin plus gentamicin for peritoneal dialysis (PD)-associated peritonitis before culture results are available is still wildly used due to concerns regarding the economic burden and antibiotic-resistant bacterial infections. The aim of this study is to define the factors that predict the outcome of empirical antibiotic therapy for PD peritonitis. This is a retrospective study of patients with PD peritonitis over the last 10 years. Patients who had been treated empirically with intermittent intraperitoneal first-generation cephalosporin and gentamicin were enrolled. Eighty-three patients had 192 episodes of PD peritonitis. In total, 159 peritonitis episodes were treated with intraperitoneal antibiotics combined with first-generation cephalosporin and gentamicin empirically. Twenty-five peritonitis episodes had no pathogens identified by dialysate culture. In total, 122 (122/159, 76.7%) PD peritonitis episodes were caused by bacteria, 9 (9/159, 5.7%) were fungal, and 3 (3/159, 1.9%) were Mycobacterium tuberculosis peritonitis. Sixty-four (64/159, 40.3%) peritonitis episodes were successfully cured by empirical intraperitoneal antibiotic therapy. Empirical antibiotic treatment failed in 95 episodes (95/159, 59.7%). The positive rates of dialysate Gram stain in the empirical treatment success and failure groups were 15.6% and 40.0%, respectively (P = 0.001). The odds ratio of empirical treatment failure with a positive bacteria Gram stain was 3.60 (95% CI: 1.65-7.82). The dialysate Gram staining result was a significant predictor of empirical antibiotics treatment outcome for PD-associated peritonitis. Therefore, using an empirical antibiotic regimen for patients with an initial positive bacterial Gram stain of the dialysate should be introduced cautiously.

Peritoneal cells at admission: do they have prognostic significance in peritonitis?

Peritonitis accounts for considerable morbidity and hospitalization in peritoneal dialysis (PD) patients. We investigated the factors related with time of hospital stay, especially focusing on the peritoneal cell profiles at the time of hospital admission in PD-related peritonitis. Eighty peritonitis attacks were evaluated. Data were collected at the time of hospital admission, clinical and biochemical parameters, including initial systemic and dialysate white cell counts (including percentage and differential count of neutrophils and lymphocytes) and length of hospital stay. Peritoneal leukocyte (r=+0.289, p=0.009) and neutrophil counts (r=+0.403, p<0.0001), peritoneal neutrophil percentage (r=+0.492, p<0.0001), time of hospital admission (r=+0.498, p<0.0001), and C-reactive protein (CRP) (r=+0.231, p=0.042) were positively correlated; lymphomononuclear cell percentage (r=-0.650, p<0.0001) was negatively correlated with hospitalization length. Hospital admission>or=24 hours of symptom onset was associated with higher CRP, dialysate leukocyte and neutrophil counts, longer hospitalization, and with lower dialysate lymphomononuclear cell percentage compared to admission<24 hours (p=0.04, p=0.04, p=0.005, p<0.0001, and p=0.04, respectively). In multiple linear regression, the time of hospital admission (p=0.002), initial peritoneal neutrophil count (p=0.011), and lymphomononuclear cell percentage (p<0.0001) were independently associated with hospitalization length. Hospital admission within first 24 hours of peritonitis symptoms onset is of vital importance; delayed admission is associated with higher peritoneal leukocyte and neutrophil counts, and increased length of hospital stay.

Enterococcal peritonitis in children receiving chronic peritoneal dialysis

BACKGROUND

Peritonitis is a common complication of chronic peritoneal dialysis (CPD) and can be associated with technique failure. Enterococcus is an uncommon peritoneal pathogen in children receiving CPD but represents a potential therapeutic challenge due to its innate resistance to cephalosporins and emerging resistance to glycopeptides.

METHODS

The International Pediatric Peritonitis Registry is a global consortium of 47 paediatric dialysis centres designed to address validation of the International Society for Peritoneal Dialysis paediatric peritonitis treatment guidelines. Between 2001 and 2004, peritonitis episodes were assessed in 392 participating children receiving CPD.

RESULTS

Among the 392 patients, 340 episodes of culture-positive peritonitis were evaluated. Twenty of these episodes were due to Enterococcus species (5.9%). There were no clinical characteristics uniquely associated with enterococcal peritonitis at presentation. After 3 days of therapy, 75% of patients were pain free, 95% had decreased effluent cloudiness and 90% were afebrile. Only one patient required a catheter exchange, and all patients experienced full functional recovery. Despite broad in vitro resistance to cephalosporins and 21% resistance to glycopeptides, neither in vitro resistance pattern nor choice of empiric antibiotic regimen affected short- or long-term outcomes.

CONCLUSIONS

Enterococci are likely responsible for ∼6% of culture-positive peritonitis episodes in children receiving CPD. Although it was not possible to identify patients with enterococcal peritonitis based on presentation, clinical response was not associated with in vitro resistance patterns, and patients who initially received a cephalosporin-based empiric regimen until culture results are available are likely to respond quickly and have full functional recovery.

Persistent symptomatic intra-abdominal collection after catheter removal for PD-related peritonitis

BACKGROUND

Peritoneal dialysis (PD) patients with severe peritonitis require catheter removal. It is often assumed that this approach, together with antibiotics, would eradicate the infection; however, some patients continue to have problems despite catheter removal.

METHOD

We reviewed 30 consecutive PD patients in our center from 1997 to 2008 with recurrent loculated peritoneal collection after catheter removal for severe peritonitis.

RESULTS

Of the 1928 episodes of peritonitis that occurred in 702 patients during the study period, 11.1% required catheter removal and 1.6% developed recurrent peritoneal collection that required percutaneous drainage. Median time to diagnosis of intra-abdominal collection was 12 days after catheter removal (interquartile range 7 - 61 days). In 25 patients (83.3%), aspirate of the abdominal collection was culture negative. In 17 patients (56.7%), the abdominal collection was recurrent and required repeated percutaneous aspiration. Only 3 patients had successful reinsertion of the peritoneal catheter but all had reduced small solute clearance after returning to PD.

CONCLUSION

A small but not negligible proportion of patients with PD-related peritonitis develop recurrent intra-abdominal collection that requires percutaneous drainage after catheter removal. The chance of a successful return to PD is very low in this group of patients. Direct conversion to long-term hemodialysis may avoid unnecessary attempts at peritoneal catheter reinsertion.

Prognostic Survival Factors in Elderly Renal Failure Patients Treated with Peritoneal Dialysis: A Nine-Year Retrospective Study

Background

Few studies specifically investigating elderly patients on peritoneal dialysis (PD) have been conducted and great uncertainty remains on the factors involved in the vital prognosis. The objective of this study was to describe our population of patients aged 75 years or older at the time PD was initiated and to study their survival in terms of the relevant nephro-geriatric criteria inventoried at the beginning of treatment.

Methods

We retrospectively analyzed the data of all the elderly patients that began first-line PD in our center between 1 January 1997 and 31 July 2006 ( n = 112).

Results

Mean duration of survival on PD was 19.6 ± 13.9 months; by the end of the study 87 patients had died and 7 had been transferred to hemodialysis. The Cox model multivariate analysis of survival allowed us to select 5 independent predictive variables that had a considerable impact on survival: absence of nephrologic care before dialysis, associated comorbidities (Charlson Comorbidity Index), loss of physical and/or mental autonomy (AGGIR group), and polymedication. Above and beyond the weight of these clinical variables, institutionalization or, more generally, social isolation was a determining factor for the duration of survival in PD.

Conclusion

Any patient considered for peritoneal dialysis should be evaluated by a multidisciplinary team in collaboration with geriatric specialists for both the overall medical situation and the social and family environment.

The role of virulence factors in the outcome of staphylococcal peritonitis in CAPD patients

Background

Peritonitis continues to be the most frequent cause of peritoneal dialysis (PD) failure, with an important impact on patient mortality. Gram-positive cocci such as Staphylococcus epidermidis, other coagulase-negative staphylococci (CoNS), and Staphylococcus aureus are the most frequent etiological agents of PD-associated peritonitis worldwide. The objective of the present study was to compare peritonitis caused by S. aureus and CoNS and to evaluate the factors influencing outcome.

Methods

Records of 86 new episodes of staphylococcal peritonitis that occurred between 1996 and 2000 in the Dialysis unit of a single university hospital were studied (35 due to S. aureus, 24 to S. epidermidis and 27 to other CoNS). The production of slime, lipase, lecithinase, nuclease (DNAse), thermonuclease (TNAse), α- and β-hemolysin, enterotoxins (SEA, SEB, SEC, SED) and toxic shock syndrome toxin-1 (TSST-1) was studied in S. aureus and CoNS. Antimicrobial susceptibility was evaluated based on the minimal inhibitory concentration determined by the E-test. Outcome predictors were evaluated by two logistic regression models.

Results

The oxacillin susceptibility rate was 85.7% for S. aureus, 41.6% for S. epidermidis, and 51.8% for other CoNS (p = 0.001). Production of toxins and enzymes, except for enterotoxin A and α-hemolysin, was associated with S. aureus episodes (p < 0.001), whereas slime production was positive in 23.5% of CoNS and 8.6% of S. aureus strains (p = 0.0047). The first model did not include enzymes and toxins due to their association with S. aureus. The odds of resolution were 9.5 times higher for S. epidermidis than for S. aureus (p = 0.02) episodes, and were similar for S. epidermidis and other CoNS (p = 0.8). The resolution odds were 68 times higher for non-slime producers (p = 0.001) and were not influenced by oxacillin resistance among vancomycin-treated cases (p = 0.89). In the second model, the resolution rate was similar for S. aureus and S. epidermidis (p = 0.70), and slime (p = 0.001) and α-hemolysin (p = 0.04) production were independent predictors of non-resolution.

Conclusion

Bacterial species and virulence factors rather than antibiotic resistance influence the outcome of staphylococcal peritonitis.

Enterococcal peritonitis in Australian peritoneal dialysis patients: predictors, treatment and outcomes in 116 cases

Background. Enterococcal peritonitis is a serious complication of peritoneal dialysis (PD), although reports of this condition in the literature are exceedingly limited. Methods. The frequency, predictors, treatment and clinical outcomes of enterococcal peritonitis were investigated in all 4675 patients receiving PD in Australia between 1 October 2003 and 31 December 2006. Results. One hundred and sixteen episodes of enterococcal peritonitis occurred in 103 individuals. Enterococcal peritonitis tended to be associated with older age, Maori and Pacific Islander racial origin, renovascular disease and coronary artery disease. Polymicrobial peritonitis, defined as recovery of two or more organisms from dialysate effluent, was significantly more common when an Enterococcus species was isolated than when it was not (45% vs 5%, respectively, P < 0.001, odds ratio 13.4, 95% CI 9.45-19.0). Although international guidelines recommend intraperitoneal ampicillin therapy, only 8% of patients with pure enterococcal peritonitis were treated with this agent, whilst the majority (78%) received vancomycin monotherapy. Overall, 59 (51%) patients with enterococcal peritonitis were successfully treated with antibiotics without experiencing relapse, catheter removal or death. The sole independent predictor of adverse clinical outcomes was recovery of additional (non-Enterococcus) organisms. Polymicrobial enterococcal peritonitis was associated with very high rates of hospitalization (83%), catheter removal (52%), permanent haemodialysis transfer (50%) and death (5.8%). In contrast, clinical outcomes were broadly comparable for pure enterococcal and non-enterococcal peritonitis (hospitalization 75% vs 69%, respectively; catheter removal 25% vs 21%; permanent haemodialysis transfer 17% vs 17%; death 1.6% vs 2.2%) although worse than non-enterococcal Gram-positive peritonitis (63%, 12%, 3% and 0.6%, respectively). Removal of the PD catheter within 1 week of enterococcal peritonitis onset was associated with a lower probability of permanent haemodialysis transfer than later removal (74% vs 100%, P = 0.03).

CONCLUSIONS

Enterococcal peritonitis is associated with an increased risk of catheter removal, permanent haemodialysis transfer and death, particularly when other organisms are isolated in the same episode.

Peritoneal dialysis-associated peritonitis: clinical features and predictors of outcome

OBJECTIVES

The objective of this study was to identify the epidemiological, clinical, and microbiological factors affecting the outcome of peritoneal dialysis (PD)-associated peritonitis.

METHODS

All patients with PD-associated peritonitis, cared for at the University Hospital of Heraklion from 1990 to 2007, were retrospectively studied.

RESULTS

A total of 247 episodes of PD-associated peritonitis occurring in 82 patients were evaluated. The median age of patients was 68 years (range 10-92 years); 51 (62%) were males. There were 104 episodes (42%) of Gram-positive peritonitis, 46 (19%) of Gram-negative peritonitis, 13 (5%) of polymicrobial peritonitis, and 11 (4%) of fungal peritonitis. There were 64 (26%) complicated episodes. The latter included 22 (8.9%) relapses, 13 (5.3%) repeated episodes, 18 (7.3%) catheter removals, and 11 (4.5%) deaths. In multivariate analysis, the presence of a purulent exit-site infection (p<0.001), peritoneal dialysis effluent cell count >100 x 10(6)/l for more than 5 days (p<0.001), use of antimicrobials during the preceding 3 months (p<0.05), and low serum total protein level on admission (p<0.05) were independent predictors of a complicated course.

CONCLUSIONS

Exit-site infection, more than 5 days with a peritoneal dialysis effluent cell count >100 x 10(6)/l, prior use of antimicrobials, and low serum total protein level are potential predictors of complicated PD-associated peritonitis and may distinguish high-risk cases.

Assessing and training patients on peritoneal dialysis in their own homes can influence better practice

Peritoneal dialysis (PD) offers the opportunity of a better quality of life for patients as long as they are able to perform dialysis according to the set procedures. Our aim in this study was to assess the change in PD patients' knowledge about their treatment and practice through repeated home visits. This study was based on the findings of a previous study. Fifteen patients participated and received two visits post training. During the visits, a questionnaire was completed, and the answers were analysed. Data were analysed by percentage statistics and assessed for differences between the two visits. The correct number of answers given during the first visit was 25.5 +/- 3.2/31 and was 27.8 +/- 4.0/31.8 at the second visit. The mean infection section and medication scores had increased from the original study findings. The personal hygiene section was the least correctly answered section. Consecutive home visits revealed that as the time on PD increased, knowledge and practice regarding infections and medication increased. Personal hygiene scores did not improve. This study confirmed the importance of home visits in detecting the weakest point of PD practice.

Streptococcal peritonitis in Australian peritoneal dialysis patients: predictors, treatment and outcomes in 287 cases

BACKGROUND

There has not been a comprehensive, multi-centre study of streptococcal peritonitis in patients on peritoneal dialysis (PD) to date.

METHODS

The predictors, treatment and clinical outcomes of streptococcal peritonitis were examined by binary logistic regression and multilevel, multivariate poisson regression in all Australian PD patients involving 66 centres between 2003 and 2006.

RESULTS

Two hundred and eighty-seven episodes of streptococcal peritonitis (4.6% of all peritonitis episodes) occurred in 256 individuals. Its occurrence was independently predicted by Aboriginal or Torres Strait Islander racial origin. Compared with other organisms, streptococcal peritonitis was associated with significantly lower risks of relapse (3% vs 15%), catheter removal (10% vs 23%) and permanent haemodialysis transfer (9% vs 18%), as well as a shorter duration of hospitalisation (5 vs 6 days). Overall, 249 (87%) patients were successfully treated with antibiotics without experiencing relapse, catheter removal or death. The majority of streptococcal peritonitis episodes were treated with either intraperitoneal vancomycin (most common) or first-generation cephalosporins for a median period of 13 days (interquartile range 8-18 days). Initial empiric antibiotic choice did not influence outcomes.

CONCLUSION

Streptococcal peritonitis is a not infrequent complication of PD, which is more common in indigenous patients. When treated with either first-generation cephalosporins or vancomycin for a period of 2 weeks, streptococcal peritonitis is associated with lower risks of relapse, catheter removal and permanent haemodialysis transfer than other forms of PD-associated peritonitis.

Impact of age on peritonitis risk in peritoneal dialysis patients: an era effect

BACKGROUND AND OBJECTIVES

Despite reductions in the frequency of peritoneal dialysis (PD)-related infectious complications over time, peritonitis and catheter infection remain important causes of morbidity and mortality. Given the increasing number of elderly patients reaching end-stage renal disease, making informed decisions about PD utilization is contingent on an understanding of the infectious complications of PD in this population. We therefore studied the impact of age on infection rates, organisms and outcomes.

DESIGN, SETTING, PARTICIPANTS AND MEASUREMENTS

On the basis of data collected from 1996 to 2005 in the multicenter Baxter Peritonitis Organism Exit sites Tunnel infections database, the study population included 4247 incident Canadian PD patients: 1265 patients aged > or =70 yr and 2982 patients aged <70 yr. We defined two eras of PD initiation: 1996 to 2000 and 2001 to 2005.

RESULTS

In a negative binomial model, older age was independently associated with a higher peritonitis rate (rate ratio [RR] 1.06 per decade increase; 95% CI 1.01 to 1.10; P = 0.008). However, this association was present only among those who initiated PD at an earlier time (RR 1.13 per decade increase; 95% CI 1.07 to 1.20; P < 0.001 in 1996 to 2000 versus 1.01 per decade increase; 95% CI 0.95 to 1.06; P = 0.81 in 2001 to 2005). Catheter-related infections were less frequent with increasing age regardless of era (RR 0.93 per decade increase; 95% CI 0.89 to 0.97).

CONCLUSIONS

The higher peritonitis rate observed in elderly patients may represent an era effect, as age was not associated with peritonitis among patients initiating PD between 2001 and 2005. In addition, catheter infection was less frequent with increasing age.

Risk Factors for Adverse Outcomes after Peritonitis-Related Technique Failure

Background

Peritonitis is the leading cause of technique failure in peritoneal dialysis (PD) patients. Some patients experience recurrent ascites, encapsulating peritoneal sclerosis (EPS), and even death after catheter removal. Little is known, however, about the risk factors for such complications.

Methods

The study subjects were 117 patients that had their PD catheter removed due to peritonitis between January 2000 and June 2006. Biochemical and clinical data were reviewed retrospectively. Serum C-reactive protein (CRP) and blood and effluent white blood cell counts (WBC) were measured at baseline and at 72 hours of peritonitis. Based on adverse outcomes, patients were classified into 4 groups: non-complication (NC; n = 73), recurrent ascites (A; n = 26), EPS (E; n = 10), and death directly related to peritonitis (D; n = 8).

Results

Age at PD catheter removal was significantly higher in D group compared to NC group (62.0 ± 10.6 vs 51.2 ± 11.5 years, p < 0.05). In addition, mean PD duration was significantly longer in E group compared to NC and A groups (130.5 ± 48.1 vs 58.8 ± 42.4 vs 74.8 ± 47.4 months, p < 0.01). Compared to baseline, effluent WBC was significantly decreased in NC group after 72 hours of peritonitis. In addition, serum CRP level was significantly decreased in NC and A groups, whereas it was significantly increased in D group. Multivariate analyses adjusted for age, PD duration, blood and effluent WBC, serum CRP, and micro-organisms revealed that serum CRP level at 72 hours predicted significantly the development of EPS [odds ratio (OR) 1.15, p < 0.05] and peritonitis-related death (OR 1.18, p < 0.01). In addition, PD duration (per 1 month increase: OR 1.03, p < 0.05) and age at PD catheter removal (per 1 year increase: OR 1.11, p < 0.05) were identified as significant determinants of EPS and peritonitis-related death respectively. Only effluent WBC at 72 hours was significantly associated with the development of ascites (OR 1.27, p < 0.05).

Conclusion

Older patients with long PD duration and those with persistently elevated serum CRP levels were likely to develop complications after peritonitis-related technique failure. Our study suggests that serial measurement of CRP may be helpful in predicting the development of complications after PD catheter removal.

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.

Is Computerized Tomography Useful in Identifying Abdominal Catastrophes in Patients Presenting with Peritonitis?

Background

Peritonitis is a significant source of morbidity and mortality in patients on peritoneal dialysis (PD). Symptoms may persist, requiring an emergency laparotomy. Although increasingly used, we find that, in PD patients, abdominal computerized tomography (CT) is ineffective in determining significant pathology. This study was undertaken to assess the diagnostic utility of CT for the identification of intra-abdominal collections in PD patients presenting with peritonitis.

Methods

A retrospective chart review was undertaken of all patients that underwent abdominal CT scanning in the context of severe PD peritonitis in the past 2 years. All of these patients had at least one CT scan preoperatively.

Results

133 patients presented with PD peritonitis; 19 patients had a contrast CT procedure (12 females, 7 males). Average age was 59.2 years; mean duration on PD was 43.8 months. 13 of 19 patients had gram-negative bacillary peritonitis, 6 of whom had polymicrobial peritonitis; 4 patients had fungal peritonitis and 2 had Staphylococcus aureus peritonitis. 26 CT scans were done in 19 patients an average of 10 days after presentation. 21 of 26 scans revealed no collections of surgical interest. 12 laparotomies were performed, with an average delay of 10.4 days from presentation to laparotomy. Of the 12 laparotomies, 6 found a drainable collection not seen on CT. Seven of the 19 patients died (37%) and no patient was able to return to PD.

Conclusion

PD patients requiring emergency laparotomy following PD peritonitis have a high mortality rate. A negative abdominal CT in the setting of ongoing symptoms should not be taken as reassuring, nor should it delay proceeding to emergency laparotomy.

Icodextrin does not impact infectious and culture-negative peritonitis rates in peritoneal dialysis patients: a 2-year multicentre, comparative, prospective cohort study

Background. Icodextrin is a glucose polymer derived by hydrolysis of cornstarch. The different biocompatibility profile of icodextrin-containing peritoneal dialysis (PD) solutions may have a positive influence on peritoneal host defence. Furthermore, cases of sterile peritonitis potentially associated with icodextrin have been reported.

Methods. The primary objective of this multicentre, longitudinal, observational, non-interventional, prospective cohort study, which included 722 PD patients, was to evaluate the incidence of overall peritonitis in patients treated with icodextrin-containing PD solutions (Extraneal™) used during one long-dwell exchange/day compared with those treated with non-icodextrin-containing PD solutions. The secondary objective was to determine if culture-negative peritonitis rates differed between patients treated with icodextrin from two independent manufacturers. All peritonitis episodes were assessed by a Steering Committee in a blind manner.

Results. There was no significant difference between icodextrin-treated and control patients in the adjusted overall, culture-positive or culture-negative peritonitis rates. When stratified by the icodextrin supplier, there was no significant difference in the adjusted rate of culture-negative peritonitis episodes between groups.

Conclusion. Subjects receiving icodextrin as part of their PD regimen experienced neither a higher rate of culture-negative peritonitis nor a lower rate of infectious peritonitis compared with non-icodextrin users. There was no significant influence of the icodextrin raw material supplier on peritonitis rates.

Receptor-interacting protein 2 is a marker for resolution of peritoneal dialysis-associated peritonitis

There are no predictive factors for peritoneal dialysis-associated peritonitis; however, its resolution correlates with a cell-mediated Th1 immune response. We tested the hypothesis that induction of receptor-interacting protein 2 (RIP2), an assumed kinase linked with Th1 responses, is a useful marker in this clinical setting. Basal RIP2 expression was measured in human immune cells and during dialysis-associated peritonitis. RIP2 increased with bacterial toxin cell activation and the temporal profile for this differed depending on immune cell involvement in the innate or adaptive phases of the response. Importantly, RIP2 expression increased in peritoneal immune cells during dialysis-associated peritonitis and this upregulation correlated with clinical outcome. An early induction in peritoneal CD14(+) cells correlated with rapid resolution, whereas minimal induction correlated with protracted infection and with catheter loss in 36% of patients. These latter patients had higher levels of MCP-1 consistent with a delayed transition from innate to adaptive immunity. Our study shows that upregulation of RIP2 is a useful marker to monitor dialysis-associated peritonitis and in predicting the clinical outcome of these infections.

Peritonitis in children who receive long-term peritoneal dialysis: a prospective evaluation of therapeutic guidelines

In children who are on chronic peritoneal dialysis, peritonitis is the primary complication compromising technique survival, and the optimal therapy of peritonitis remains uncertain. An Internet-based International Pediatric Peritonitis Registry was established in 47 pediatric centers from 14 countries to evaluate the efficacy and safety of largely opinion-based peritonitis treatment guidelines in which empiric antibiotic therapy was stratified by disease severity. Among a total of 491 episodes of nonfungal peritonitis entered into the registry, Gram-positive organisms were cultured in 44%, Gram-negative organisms were cultured in 25%, and cultures remained negative in 31% of the episodes. In vitro evaluation revealed 69% sensitivity of Gram-positive organisms to a first-generation cephalosporin and 80% sensitivity of Gram-negative organisms to a third-generation cephalosporin. Neither the risk factors assumed by the guidelines nor the choice of empiric therapy was predictive of either the early treatment response or the final functional outcome of the peritonitis episodes. Overall, 89% of cases achieved full functional recovery, a portion after relapsing peritonitis (9%). These data serve as the basis for new evidence-based guidelines. Modification of empiric therapy to include aminoglycosides should be considered.

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.

Higher serum C-reactive protein predicts short and long-term outcomes in peritoneal dialysis-associated peritonitis

We examined the association between C-reactive protein (CRP) and short- and long-term adverse outcomes in peritoneal dialysis (PD)-associated peritonitis. Serum CRP levels were measured at baseline and 3 weeks after initiation of treatment in 209 patients with an incident episode of peritonitis between 1 January 1999 and 31 March 2005. Patients were followed until 31 May 2005. Short-term adverse outcomes included switch to hemodialysis, death, persistent infection beyond planned therapy duration, and relapse; long-term adverse outcomes included a subsequent peritonitis event or death. After adjustment for age, gender, diabetes, duration of renal replacement therapy and causative organism, patients with higher CRP levels at diagnosis had a greater odds of an adverse short-term outcome (odds ratio 1.57 (95% confidence interval (CI): 0.61-4.02), 2.73 (95% CI: 1.09-6.87), and 3.38 (95% CI: 1.36-8.42) in the second, third, and highest quartiles). In patients who met criteria for resolution of peritonitis 3 weeks after diagnosis, those with higher CRP levels had a greater risk of a long-term adverse outcome (hazard ratio 1.79 (95% CI: 1.05-3.07)). In conclusion, higher levels of CRP are independently associated with adverse outcomes in PD-associated peritonitis. Serial measurement of this marker during the course of peritonitis may facilitate earlier identification of individuals at greater risk of complications.

A survey of peritonitis and exit-site and/or tunnel infections in Japanese children on PD

To obtain data on peritonitis and exit-site and/or tunnel infections (ESI/TI) in Japanese children undergoing peritoneal dialysis (PD) from January 1999 through June 2003, we surveyed 22 members of the Japanese Study Group of Pediatric Peritoneal Dialysis (JSPPD) by questionnaire. One hundred and thirty patients were eligible. Seventy episodes of bacterial peritonitis occurred in 45 patients (0.17 episodes/patient-year), and 123 ESI/TI occurred in 60 patients (0.29 episodes/patient-year). S. aureus and MRSA were found to be the causative organisms in 39% and 13% of the peritonitis episodes, and in 59% and 20% of the ESI/TI, respectively. Tunnel infection was found in 55% of the MRSA peritonitis episodes. Eleven percent of the peritonitis episodes relapsed, and 19% needed hemodialysis. One patient died due to MRSA peritonitis. The PD catheter was removed in all fungal and 78% of MRSA peritonitis. However, the type of organism did not influence the need for catheter-related surgery for ESI/TI. Neither peritonitis nor ESI/TI was prevented by the use of a swan-neck catheter, a downward-pointing exit site, povidone iodine exit-site care, bathing instruments, or nasal mupirocin. In conclusion, MRSA peritonitis was not uncommon in children in Japan, was frequently associated with tunnel infections, and had a poor outcome. No association was found between the occurrence of infection and preventive measures previously reported as effective. Alternative approaches are needed in children, especially for MRSA.

Predictive value of dialysate cell counts in peritonitis complicating peritoneal dialysis

Early prediction of outcomes has major potential implications regarding the management of dialysis-related peritonitis. The outcomes of 565 consecutive episodes of peritonitis complicating peritoneal dialysis between August 2001 and July 2005 were evaluated in relation to the dialysate cell counts. Discriminatory power, based on the area under the receiver-operating characteristic (ROC) curves, of the cell counts was assessed. The findings then were validated externally in a cohort of 217 peritonitis episodes from another dialysis unit. During the study period, 565 episodes of peritonitis were included for analysis, 465 of which had treatment success defined as complete resolution of peritonitis without the need for Tenckhoff catheter removal. Of the remaining 100 episodes (treatment failure), 70 required Tenckhoff catheter removal and 30 had peritonitis-related death. The peritoneal dialysate total white blood cell count on day 3 of peritonitis predicted treatment failure independent of standard risk factors, and it had a higher area under the ROC curve than the dialysate white cell count on day 1 (0.80 versus 0.58; P < 0.0001). Using a peritoneal dialysate white count cut point > or = 1090/mm3 on day 3, the sensitivity was 75% and the specificity was 74% for the prediction of treatment failure (defined as catheter loss or peritonitis-related death). In multiple logistic regression analyses, peritoneal dialysate white count > or = 1090/mm3 on day 3 was an independent prognostic marker for treatment failure after adjustment for conventional risk factors (hazard ratio 9.03; 95% confidence interval 4.40 to 18.6; P < 0.0001). Number of years on peritoneal dialysis; diabetes; gram-negative organisms; and Pseudomonas, fungal, or Mycobacterium species were other independent risk factors that were predictive of treatment failure. Findings from an independent validation set of peritonitis (217 episodes after exclusion of Mycobacterium and fungal causes) also favored the peritoneal dialysate white count on day 3, as compared with day 1 and day 2, to predict treatment failure. Area under the ROC curve for the white counts on day 3 was 0.98 (95% confidence interval 0.95 to 0.99) in the validation set. This study demonstrated and cross-validated the superiority of peritoneal dialysate white cell count on day 3 to predict outcomes of dialysis-related peritonitis. These results call attention to the value of validating prognostic factors of peritonitis complicating peritoneal dialysis.