Feasibility of resuming peritoneal dialysis after severe peritonitis and Tenckhoff catheter removal

A predictive model of treatment effectiveness of refractory peritoneal dialysis-related peritonitis in patients with peritoneal dialysis: a single-center observational study in South China

Background

To prevent loss of peritoneal function caused by persistent abdominal inflammation, the guidelines recommend early extubation in patients with refractory peritoneal dialysis (PD)-associated peritonitis (rPDAP). In attempt to pinpoint high-risk patient cohorts that did not respond to treatment for refractory peritonitis, we created a model to predict the effectiveness of peritonitis treatment.

Methods

This observational cohort study included PD patients from 1 January 2011 to 31 December 2020. Multivariate logistic regression analysis was used to explore the factors affecting the occurrence and prognosis of rPDAP, and to construct a predictive model for the success of rPDAP treatment. Receiver operator characteristic curve, calibration and decision curve were drawn to evaluate the predictive performance of the model.

Results

A total of 1397 cases of PDAP occurred in our center during the study period, of which 558 cases were diagnosed as rPDAP. The incidence of refractory peritonitis was 0.047 cases/patient-year. In the study, 440 cases with rPDAP were included. Among them, 304 cases (69.1%) had been successfully cured, while 136 cases (30.9%) were treatment failure, of which 19 cases (13.9%) died, 85 cases (62.5%) transferred to hemodialysis and 32 cases (23.5%) were relapse/recurrent peritonitis. Dialysate culture results showed 132 (30.0%) cases were infected with Gram-positive bacteria and 161 (36.6%) Gram-negative bacteria. Multivariate logistic regression analysis showed that episodes of peritonitis previously ≤3 times were correlated with the better prognosis of rPDAP, but white blood cell (WBC) counts in peritoneal dialysate on the third day of peritonitis or WBC counts on the fifth day ≥300 × 106/L, the pathogenic microorganism with Gram-negative bacteria, as well as longer duration of PD were associated with poor outcomes. The C-statistical value of the training data set was 0.870 (95% confidence interval 0.821-0.918). The calibration curve and clinical decision-making curve also proved that this nomogram could accurately predict the success of treatment in patients with refractory peritonitis.

Conclusion

The nomogram model created through internal verification indicated a strong clinical application value and a high prognostic prediction accuracy for rPDAP.

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

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

Staphylococcus lugdunensis Peritoneal Dialysis-Related Peritonitis: A Matched Comparative Analysis

Rationale & Objective

Staphylococcus lugdunensis (S lugdunensis) is a coagulase-negative staphylococcus species that has been increasingly recognized to cause serious infections with virulence resembling Staphylococcus aureus (S aureus). No studies have evaluated the characteristics and outcomes of patients with S lugdunensis peritoneal dialysis-related peritonitis compared with those with S aureus peritonitis. We aim to evaluate the clinical course of peritonitis as caused by these organisms.

Study Design

A retrospective matched comparative analysis involving a single tertiary center from July 2000 to July 2020.

Setting & Participants

Forty-eight episodes of S aureus peritonitis were matched to 19 cases of S lugdunensis peritonitis.

Analytical Approach

The cases were individually matched for year of peritonitis, sex, age (±10 years), and Charlson Comorbidity Index (±3). A comparative analysis was performed between the 2 organisms. The outcome includes responses at day 5 of peritonitis and the rate of complete response.

Results

There is a higher predilection of diabetes in those with S aureus peritonitis than in those with S lugdunensis (64.6% vs 31.6%; P = 0.03). Patients with S aureus peritonitis also have a much higher total cell count at presentation (4,463.9 ± 5,479.5 vs 1,807.9 ± 3,322.7; P = 0.05); a higher prevalence of poor response at day 5 (50.0% vs 15.8%; P = 0.03); a lower rate of complete response (64.6% vs 94.7%; P = 0.01) and are more prone to relapse with the same organism (29.2% vs 0%, respectively; P = 0.01) as compared to those with S lugdunensis.

Limitations

The result of this small retrospective study involving a single center may not be generalizable to other centers. There is also no data for comparative analysis on other coagulase-negative staphylococci such as Staphylococcus epidermidis, which belongs to the same family as S lugdunensis.

Conclusions

Although S aureus peritonitis is more virulent with significant morbidity, S lugdunensis can cause similarly serious peritonitis. This largest case series of S lugdunensis peritonitis enabled better characterization of clinical features and outcomes of patients with S lugdunensis peritonitis.

ISPD Catheter-related Infection Recommendations: 2023 Update

Peritoneal dialysis (PD) catheter-related infections are important risk factors for catheter loss and peritonitis. The 2023 updated recommendations have revised and clarified definitions and classifications of exit site infection and tunnel infection. A new target for the overall exit site infection rate should be no more than 0.40 episodes per year at risk. The recommendation about topical antibiotic cream or ointment to catheter exit site has been downgraded. New recommendations include clarified suggestion of exit site dressing cover and updated antibiotic treatment duration with emphasis on early clinical monitoring to ascertain duration of therapy. In addition to catheter removal and reinsertion, other catheter interventions including external cuff removal or shaving, and exit site relocation are suggested.

Simultaneous replacement and removal of the peritoneal catheter is effective in patients with refractory tunnel infections sustained by S. aureus

BACKGROUND

In tunnel infection (TI) refractory to medical therapy or in case of TI that occurs simultaneously with peritonitis, the removal of the peritoneal catheter has been proposed. This approach requires the interruption of peritoneal dialysis (PD) and the creation of a temporary vascular access. However, simultaneous removal and reinsertion of the PD catheter (SCR) represents another possible therapeutic approach.

METHODS

We analysed the outcome of 20 patients (10 men and 10 women, mean age 65.5 ± 16.3 years) treated by CAPD for a mean period of 24.3 ± 14.2 months who underwent to SCR for the treatment of TI unresponsive to medical therapy or TI that occurred simultaneously with peritonitis at Fondazione Ca' Granda Ospedale Maggiore Policlinico. All the patients restarted CAPD exchanges within 24 h from catheter placement.

RESULTS

SCR was successful in 80% (16/20) of the cases. In particular, SCR was effective in 100% (11/11) of the TI with or without associated peritonitis sustained by S. aureus. However, SCR failed in 57% (4/7) of TI associated with relapsing peritonitis and in one patient with TI secondary to Enterobacter. No early mechanical complications (within 3 months after SCR) occurred when CAPD was restarted.

CONCLUSIONS

SCR of the PD catheter through double-purse string technique represents an effective treatment for TI without or with simultaneously peritonitis sustained by S. aureus avoiding the patient the need for temporary hemodialysis and second surgical procedure. However, SCR could be contraindicated in case of relapsing peritonitis.

Excessive risk and poor outcome of hospital-acquired peritoneal dialysis-related peritonitis

Background

Peritoneal dialysis (PD) is a home-based renal replacement therapy. Since hospital staff are not often familiar with PD and its complications, PD patients may have an excess risk of developing PD-related peritonitis during hospital admission for unrelated reasons, and the outcome may be affected.

Methods

We reviewed 371 episodes of hospital-acquired PD-peritonitis in our center from 2000 to 2019. Their clinical characteristics and outcome were compared to 825 episodes that required hospital admission, and 1964 episodes that were treated as out-patient.

Result

Hospitalized PD patients had a significantly higher risk of developing peritonitis than out-patient ones (incident rate ratio 4.41, 95% confidence interval [CI] 3.95–4.91). Hospital-acquired peritonitis episodes were more commonly culture negative. Bacterial isolates from the hospital acquired episodes were more likely resistant to ceftazidime (p < 0.0001) than the other groups. The primary response rate, complete cure rate, and overall mortality of the hospital-acquired episode were 66.6%, 62.0%, and 23.2% respectively, all worse than episodes that developed outside the hospital (p < 0.0001 for all).

Conclusion

PD patients admitted to the hospital had a 4-fold increase in the risk of developing peritonitis. Hospital-acquired peritonitis episodes were more likely culture negative, be resistant to antibiotics. They also had a lower primary response rate, lower complete cure rate, and a higher mortality than episodes that developed outside hospital.

The Clinical Utility of the Neutrophil-to-Lymphocyte Ratio as a Discriminatory Test among Bacterial, Mycobacterium Tuberculosis, and Nontuberculous Mycobacterium Peritoneal Dialysis-Related Peritonitis

Background

Distinguishing Mycobacterium tuberculosis (TB) and nontuberculous Mycobacterium (NTM) from bacterial peritoneal dialysis (PD)-related peritonitis (peritonitis) is often very challenging and can lead to a significant delay in diagnosis and treatment. The neutrophil-to-lymphocyte ratio (NLR) is readily calculable and has been shown to be useful in differentiating pulmonary TB from bacterial pneumonia. We are the first group to demonstrate the predictive efficacy of peritoneal dialysate (PDE) NLR in distinguishing TB/NTM peritonitis from bacterial causes in the PD population.

Methods

We retrospectively reviewed the clinical and laboratory characteristics of all patients with TB/NTM peritonitis, methicillin-sensitive Staphylococcus aureus (MSSA) peritonitis, and culture-negative peritonitis in our tertiary center between July 2000 and July 2020. The diagnostic ability of the blood and PDE NLR for differential diagnosis was evaluated.

Results

In total, 258 episodes, 38 episodes, and 27 episodes were caused by MSSA, TB, and NTM species, respectively; 364 episodes were culture negative. The PDE NLR level taken at presentation were lowest in the TB peritonitis, followed by the NTM, culture-negative, and MSSA groups, (9.44±13.01, 16.99±23.96, 36.63±32.33, 48.51±36.01; P<0.001, respectively). The area under the receiver operating characteristic curve for the NLR taken at presentation was 0.83 (95% confidence interval, 0.77 to 0.89; P<0.001). A PDE NLR <15 was an optimal cut-off value with sensitivity, specificity, positive predictive value, and negative predictive values of 81%, 70%, 97%, and 22%, respectively.

Conclusions

The PDE NLR obtained at presentation is a useful and easily accessible marker to discriminate TB/NTM peritonitis from bacterial peritonitis, especially in areas with intermediate TB/NTM burden. The NLR may enable early prompting of TB/NTM peritonitis, allowing specific investigation and treatment to be instigated earlier.

Recent advances in novel diagnostic testing for peritoneal dialysis-related peritonitis

Peritoneal dialysis-related peritonitis remains a significant complication and an important cause of technique failure. Based on current International Society for Peritoneal Dialysis guidelines, diagnosis of peritonitis is made when two of the three following criteria are met: 1) clinical features consistent with peritonitis; 2) dialysis effluent white blood cell count of >100 cells/μL; 3) positive effluent culture. However, early and accurate diagnosis can still be faulty, and emphasis has been placed on improving the timeliness and accuracy of diagnosis to facilitate early effective treatment. There have been advances in the novel diagnostic tests such as point-of-care molecular tests, genetics sequencing, mass spectrometry, and machine learning algorithm with immune fingerprinting. This article will discuss the latest evidence and updates of these tests in the management of peritoneal dialysis-related peritonitis.

Extended antibiotic therapy for the prevention of relapsing and recurrent peritonitis in peritoneal dialysis patients: a randomized controlled trial

Background

Relapsing and recurrent peritonitis episodes are major causes of technique failure in peritoneal dialysis (PD). We examined the efficacy of extended antibiotic therapy for the prevention of relapsing and recurrent peritonitis.

Methods

From February 2016 to November 2018 we recruited 254 PD patients who fulfilled the diagnostic criteria for PD peritonitis. They were randomized to a standard group, with the duration of intraperitoneal (IP) antibiotic treatment following the International Society for Peritoneal Dialysis (ISPD) guideline according to the causative microorganisms, and an extended group, with 1 extra week of IP antibiotics. The primary endpoint was relapsing, recurrent or repeat peritonitis episodes within 6 months.

Results

The primary endpoint developed in 36 and 29 patients of the extended and standard groups, respectively (28.3% versus 22.8%; P = 0.34). The rate of complete cure, without relapsing, recurrent or repeat peritonitis within 6 months, was 63.8 and 69.3% for the extended and standard groups, respectively (P = 0.35). Repeat peritonitis episodes were more common in the extended than the standard group (15.0% versus 5.5%; P = 0.013).

Conclusions

In patients with PD-related peritonitis, extending the antibiotic therapy for 1 extra week beyond the ISPD protocol should not be recommended. Extending the treatment does not reduce the risk of relapsing or recurrent peritonitis episodes but rather is associated with a higher risk of repeat peritonitis episodes.

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

BACKGROUND

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

METHOD

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

RESULT

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

CONCLUSION

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

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

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

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

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

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

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

Independent Effects of Renal and Peritoneal Clearances on the Mortality of Peritoneal Dialysis Patients

Objective

Previous studies show that peritoneal Kt/V is an independent predictor of survival in anuric patients receiving continuous ambulatory peritoneal dialysis (CAPD). We studied whether peritoneal Kt/V has the same effect in CAPD patients with residual renal function.

Design

Observational cohort study.

Setting

Single dialysis center in a university teaching hospital.

Patients

New and prevalent CAPD patients.

Methods

We examined the 5-year follow-up results of our prospective study previously reported ( Kidney Int 2000; 58:400–7). A total of 270 CAPD patients were followed for up to 6 years. Dialysis adequacy indices, residual renal function, and nutritional data were monitored.

Outcome Measures

Primary outcomes included mortality and technique failure. Peritoneal Kt/V rather than total Kt/V was used for multivariate survival analysis.

Results

Average duration of follow-up was 35.1 ± 22.0 months. Average peritoneal Kt/V throughout the study was 1.59 ± 0.37; median residual glomerular filtration rate (GFR) 0.82 mL/minute. Five-year actuarial patient survival was 41.5%, and technique survival was 23.1%. Multivariate analysis showed that sex, age, duration of dialysis, presence of diabetes, serum albumin, dialysate-to-plasma creatinine ratio at 24 hours, peritoneal Kt/V, residual GFR, and normalized protein nitrogen appearance were independent factors of both actuarial patient survival and technique survival. For every 0.1 unit higher peritoneal Kt/V, relative mortality risk was 0.94 (95% CI 0.89 – 0.99, p = 0.03). When prevalent and new CAPD cases were analyzed separately, peritoneal Kt/V predicted survival only for prevalent CAPD patients.

Conclusion

We conclude that, in prevalent CAPD patients with relatively low levels of peritoneal clearance and residual renal function, a higher peritoneal Kt/V is associated with better survival. Peritoneal clearance below 1.6 – 1.7 likely has a major detrimental effect on the clinical outcome of CAPD patients with little residual renal function.

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

Objective

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

Design

Retrospective study.

Setting

A single regional dialysis unit in a university teaching hospital.

Patients

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

Results

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

Conclusions

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

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

Background

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

Method

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

Results

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

Conclusion

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

Changes in Water Transport across the Peritoneum during Treatment with Continuous Ambulatory Peritoneal Dialysis in Selected Patients with and without Peritonitis

Background

The natural course of longitudinal changes in peritoneal permeability and membrane area has been studied mostly by performing single-dwell studies in selected patients during treatment with peritoneal dialysis.

Purpose

To evaluate the permeability characteristics of the peritoneal membrane by measuring drained ultrafiltration volume relative to initial glucose concentration in dialysis fluid from the start to the end of continuous ambulatory peritoneal dialysis (CAPD) treatment in a selected cohort of patients with and without peritonitis.

Design

A retrospective analysis of a group of patients whose peritoneal function was prospectively followed by recording drained ultrafiltration volume and glucose concentration in dialysis fluid for each dwell time, every day, during the time in CAPD treatment. Mean values from a 1-month period starting after the first 3 weeks of CAPD treatment were compared with the mean values from the last month of treatment. Approximately 11 500 exchanges were analyzed. Evaluations were done separately for short (day) and long (night) dwell times.

Patients and Statistics

Of 132 patients commencing CAPD treatment in the time period selected for inclusion, 51 had enough data to be included in this study. Of these, 29 patients experienced one or more episodes of successfully treated peritonitis. The selection of patients was not based upon patient characteristics, but upon criteria to satisfy predefined demands, such as number of measurements in each period, time since an episode of peritonitis, and time on CAPD treatment. Data were analyzed in three different groups: patients with episodes of peritonitis, patients without peritonitis, and both groups together. To assess changes between monthly mean at the start and at the end of CAPD, paired t-test was performed. Patients were also stratified into two groups according to low and high glucose in dialysis fluid at the start of CAPD (cutoff = 2 g/dL). Additionally, we used linear regression analyses to predict the level of drained ultrafiltration volume for a given level and change in glucose concentration. Mean treatment time for the entire group was 20 months (median 14.3 months), ranging from 6 to 69 months.

Results

No statistical differences in glucose concentrations were found between the periods compared. In the entire group there was an increase in ultrafiltration volume from the start to the end of CAPD treatment, for both day ( p = 0.009) and night ( p = 0.013) exchanges. Also, for patients without peritonitis, an increase appeared for day ( p = 0.046) and night exchanges ( p = 0.053). However, for the cohort with peritonitis, only an insignificant increase was indicated. Patient characteristics, diabetic patients, the need for glucose in dialysis fluid when commencing CAPD treatment, the number of episodes of peritonitis, and time on CAPD did not influence the change in ultrafiltration. Regression analyses showed higher ultrafiltration response to a given level and change in glucose concentration at the end of CAPD treatment compared to the start values, also for the cohort with peritonitis. The regression coefficient between these variables was also significantly changed for both day ( p < 0.0001) and night ( p = 0.027) exchanges.

Conclusion

A significant change in the regression coefficient between glucose in dialysis fluid and ultrafiltration volume reflects an increase in ultrafiltration response to a given level and change in glucose concentration during time on CAPD treatment. A parallel change after 5- and 9-hour dwells can be explained by a decrease in peritoneal surface area combined with a lesser decrease in peritoneal conductivity. However, changes in Starling forces across the peritoneal membrane are possible even in the absence of changes in peritoneal membrane characteristics.

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

Background

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

Methods

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

Results

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

Conclusions

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

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

Objectives

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

Methods

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

Results

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

Conclusions

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

Resuming peritoneal dialysis after catheter removal due to complicated peritonitis

BACKGROUND

Causes of non-resuming peritoneal dialysis (PD) after complicated peritonitis requiring peritoneal catheter (PC) removal remain poorly studied.

METHODS

We reviewed all peritonitis episodes in our center between 1997 and 2017. Patients who restarted PD after PC removal (Group 1) were compared to those who did not (Group 2), identifying the causes.

RESULTS

Of 284 peritonitis episodes, PC was removed in 48 patients (16.9%). In 18 (37.5%) patients PC was reinserted, and PD successfully resumed in all, with a median duration of PD afterwards of 14.1 months. In other 30 (62.5%) reinsertion of PC was not attempted. Causes of non-reinsertion were: transfer to hemodialysis 76.6% (n = 23), death 16.7% (n = 5) and transplantation 6.7% (n = 2). Hemodialysis switch was due to non-medical reasons in 47.8% (n = 11) including fear of peritonitis, family decision and social dependence. Group 1 was younger (p = 0.041), with lower Charlson index (p = 0.045) and higher men proportion (p = 0.049). Group 1 had a better patient survival than group 2 (survival at 24 months: 67% and 53%, respectively; log-rank test p: 0.01). There were no differences in survival between groups when adjusted for significant basal characteristics.

CONCLUSIONS

Resuming PD after severe peritonitis requiring PC removal is feasible but a high proportion of patients do not restart PD for non-medical reasons, usually older patients with higher Charlson index. A properly structured interview would be a useful tool that could improve return to technique in these patients.

Peritoneal Dialysis-Associated Peritonitis

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

Outcomes following peritoneal dialysis catheter removal with reinsertion or permanent transfer to haemodialysis

INTRODUCTION

Long-term use of peritoneal dialysis catheter is associated with complications such as infection and malfunction, necessitating removal of catheter with subsequent reinsertion or permanent transfer to haemodialysis. This study aims to investigate the outcome in patients who underwent reinsertion.

METHODS AND MATERIALS

A single-centre retrospective study was performed in Singapore General Hospital for all adult incident peritoneal dialysis patients between January 2011 and January 2016. Study data were retrieved from patient electronic medical records up till 1 January 2017.

RESULTS

A total of 470 patients had peritoneal dialysis catheter insertion with median follow-up period of 29.2 (interquartile range = 16.7-49.7) months. A total of 92 patients required catheter removal. Thirty-six (39%) patients underwent catheter reinsertion. The overall technique survival at 3 and 12 months were 83% and 67%. Median time to technique failure of the second catheter was 6.74 (interquartile range = 0-50.2) months. The mean survival for patients who converted to haemodialysis and re-attempted peritoneal dialysis was comparable (54.9 ± 5.5 vs 57.3 ± 3.6 months; p = 0.75). Twelve (13%) patients had contraindication for peritoneal dialysis and were excluded from analysis. Of 11 patients who required catheter removal due to malfunction, 7 (64%) underwent catheter reinsertion and 6 (86%) patients ultimately converted to haemodialysis during study period. Of the 69 patients who had catheter removal due to infection, 29 (42%) underwent catheter reinsertion and 8 (28%) patients eventually converted to haemodialysis during the study period.

CONCLUSION

Patient survival was comparable between patients who re-attempted peritoneal dialysis and patients who transferred to haemodialysis. Patients who had previous catheter removal due to infections had favourable technique survival than those due to catheter malfunction.

Simultaneous Removal And Reinsertion of the PD Catheter in Relapsing Peritonitis

Background:Relapsing peritonitis in peritoneal dialysis (PD) is associated with lower cure rates and more hemodialysis (HD) transfers, as catheter removal is recommended in these situations. The aim of our study was to evaluate the continuation of PD without perioperative transfer to HD in patients who underwent a simultaneous catheter removal and replacement for relapsing peritonitis.Methods:This was a retrospective monocentric study. Patients with simultaneous catheter removal and replacement for relapsing peritonitis or peritonitis at high risk of relapse (fungal or Pseudomonas infection) between 1 January 2007 and 31 December 2016 were included. The events of interest were the continuation of PD without perioperative transfer to HD, postoperative complications, new infection with the same organism, and technique survival.Results:Of the 271 incident patients in PD during this period, 11 had a simultaneous catheter removal and replacement for relapsing peritonitis (8) or high risk of relapse peritonitis (3). Eight (72.7%) patients pursued PD without transfer to HD. Six infections were due to microorganisms other than gram-positive cocci. At 1 year, 7 (63.6%) of the 11 patients were still on PD. After the surgery, there were no peritonitis or catheter-related infections caused by the same organism.Conclusion:Simultaneous catheter removal and replacement for peritonitis appears to be an effective procedure for maintaining patients on PD.

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

Background

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

Methods

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

Results

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

Conclusions

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

A Retrospective Analysis of Etiology and Outcomes of Refractory CAPD Peritonitis in a Tertiary Care Center from North India

BACKGROUND

Refractory peritonitis is defined as failure of clearance of peritoneal fluid despite 5 days of appropriate antibiotic therapy. Catheter removal decreases morbidity and mortality. Data on the outcomes of refractory peritonitis and of reinitiation of peritoneal dialysis (PD) in this group of patients are sparse. The present study analyzed etiology, outcomes, and prognostic factors of refractory peritonitis as well as survival of the reinitiation of the technique.

METHODS

This was a single-center retrospective study that included 90 patients of refractory continuous ambulatory PD (CAPD) peritonitis at a tertiary care center in North India. We collected information regarding symptomatology, causes, prognostic factors, and outcomes of refractory peritonitis.

RESULTS

Ninety patients suffered 93 episodes of refractory peritonitis. Fungal peritonitis was the most common cause of refractory peritonitis. Twenty nine (31%) episodes were culture-negative. We observed no difference between culture-positive and culture-negative peritonitis. Out of 90 patients, 54 (60%) recovered while 36 (40%) died. Septic shock at presentation alone was significantly associated with mortality in our study. The immediate mortality of refractory peritonitis is high. Even in patients who were shifted to permanent hemodialysis, 33% died in the first 3 months. Mean duration of technique survival after reinitiation was 23 months (1 - 85 months). Among the 12 patients who were reinitiated on CAPD, 5 patients had technique failure due to refractory peritonitis or ultrafiltration (UF) failure.

CONCLUSION

Refractory peritonitis is associated with significant morbidity and mortality despite catheter removal. Reinitiation is confounded by residual infection, which is a concern for poor technique survival, and high immediate mortality.

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

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

Peritoneal dialysis outcomes after temporary haemodialysis transfer for peritonitis

BACKGROUND

There has not been a comprehensive examination to date of peritoneal dialysis (PD) outcomes after temporary haemodialysis (HD) transfer for peritonitis.

METHODS

The study included all incident Australian patients who experienced peritonitis between 1 October 2003, and 31 December 2011, using Australia and New Zealand Dialysis and Transplant Registry data. Patients were grouped into three categories: Interim HD, Permanent HD and Never HD based on HD transfer status after the first peritonitis. The independent predictors of HD transfer and subsequent return to PD were determined by multivariable, multilevel mixed-effects logistic regression analysis. Matched case-control analyses were performed to compare clinical outcomes (e.g. patient survival) between groups.

RESULTS

Of the 3305 patients who experienced peritonitis during the study period, 553 episodes (16.7%) resulted in transfer to HD and 101 patients subsequently returned to PD. HD transfer was significantly and independently predicted by inpatient treatment of peritonitis [odds ratio (OR) 11.45, 95% confidence interval (CI) 7.14-18.36] and the recovered microbiologic profile of organisms recognized to be associated with moderate (20-40%) to high (>40%) rates of catheter removal (moderate: OR 2.45, 95% CI 1.89-3.17; high: OR 8.63, 95% CI 6.44-11.57). Matched case-control analyses yielded comparable results among Interim, Permanent and Never HD groups in terms of patient survival (P = 0.28), death-censored technique survival [hazard ratio (HR) 0.87, 95% CI 0.59-1.28; P = 0.48] and peritonitis-free survival (HR 0.84, 95% CI 0.50-1.39, P = 0.49).

CONCLUSIONS

In an observational registry study of first peritonitis episodes, temporary HD transfer was not associated with inferior patient-level clinical outcomes when compared with others who either never required HD transfer or remained on HD permanently if all patient-level and peritonitis-related factors were considered equal. Therefore, return to PD after a temporary HD due to peritonitis should not be discouraged in appropriate PD patients.

Reinitiation of peritoneal dialysis after catheter removal for refractory peritonitis

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Optimization and evaluation of magnetic bead separation combined with matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy (MALDI-TOF MS) for proteins profiling of peritoneal dialysis effluent

Peritoneal dialysis effluent (PDE) potentially carries an archive of peptides relevant to pathological processes in abdominal and surrounding tissues. Magnetic beads and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry is one such approach that offers a unique tool for profiling of peptides, but this approach has not been used in the PDE analysis. In this study, we developed a strategy for screening PDE proteins <15 kDa and applied this technique to identify potential biomarkers for peritonitis. We examined four kinds of magnetic beads, including a carbon series (C3, C8), weak cation exchange (WCX) and immobilized metal-affinity chromatography (IMAC-Cu) beads. Samples processed with IMAC-Cu magnetic beads consistently showed more MS signals across all beads within the measured mass range. Moreover, there was no difference in the number and morphology of MS signals between concentrated and unconcentrated samples. The PDE peptidome pattern, based on a panel of 15 peaks, accurately recognized peritonitis PD patients from peritonitis-free patients with sensitivity of 90.5% and specificity of 94.7% respectively. Therefore, IMAC-Cu magnetic beads and unconcentrated samples can be used as a fast and cost-effective approach for sample preparation prior to more in-depth discovery of predictive biomarkers of disease in patients on dialysis.

Automated peritoneal dialysis in Hong Kong: there are two distinct groups of patients

AIM

To compare the clinical outcome between continuous ambulatory peritoneal dialysis (CAPD) and automated peritoneal dialysis (APD) in specific subgroups of patients.

METHODS

We reviewed the clinical outcome of 90 consecutive incident APD patients and 180 CAPD patients in our centre.

RESULTS

The median follow up was 21.9 months (inter-quartile range, 9.5 to 46.5 months). The APD group was younger and had a lower Charlson's score than the CAPD group. Furthermore, the APD group had a highly skewed distribution of the Charlson's score, indicating the possibility of two different groups of patients. Multivariate analysis showed that in addition to the treatment mode (APD vs CAPD) and Charlson's score, there was a significant interaction between the two (P = 0.043) on patient survival. For patients with Charlson's score ≤6, the APD group had a significantly better patient survival than the CAPD group (78.3% vs. 65.4% at 5 years, P = 0.039), while for patients with Charlson's score ≥7, the APD group had a worse patient survival than the CAPD group (16.3% vs. 48.4% at 5 years, P = 0.028). Similarly, Charlson's score and its interaction with treatment mode, but not the APD group per se, were independent predictors of technique survival (P = 0.013). For patients with Charlson's score ≥7, the APD group had a significantly lower technique survival than the CAPD group (8.8% vs. 34.3%, P = 0.001), while for patients with Charlson's score ≤6, the technique survival was similar (44.4% vs. 42.5%, P = 0.15). Peritonitis-free survival was 35.2% and 32.2% for APD and CAPD groups, respectively (P = 0.021), and the difference was not affected by Charlson's score.

CONCLUSIONS

Comorbid diseases had a significant interaction with the mode of PD on patient and technique survival of incident PD patients. Our result suggests that APD may offer benefit in, and only in, young patients with minimal comorbid diseases.

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

BACKGROUND AND OBJECTIVES

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

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

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

RESULTS

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

CONCLUSIONS

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

Outcomes of peritoneal dialysis catheter reinsertion: does the cause of initial removal matter?

PURPOSE

In this study, we aimed to compare patient and technique survival between the patients, in whom peritoneal dialysis (PD) catheter was removed due to severe peritonitis and then it was reinserted, and those, in whom PD catheter was removed due to non-peritonitis causes and then it was reinserted.

METHOD

Sixty-two patients, in whom PD catheter was reinserted surgically, were retrospectively analyzed in this cohort study. Group 1 consisted of 27 patients in whom PD catheter was removed due to severe peritonitis, whereas Group 2 consisted of 35 patients in whom PD catheter was removed due to non-peritonitis causes.

RESULTS

There was no significant difference between Group 1 and Group 2 in terms of the estimation of overall patient survival [43 months (95 % CI 43.6-83.7) versus 80 months (95 % CI 52.8-107.3, p 0.362]. Similarly, there was no significant difference between Group 1 and Group 2 in terms of the estimation of overall technique survival [82 months (95 % CI 0-166.0) versus 31 months (95 % CI 9.7-52.3), p 0.346].

CONCLUSION

Our results suggest that there was no significant effect of causes of PD catheter removal (peritonitis vs. non-peritonitis) on the outcomes of PD treatment.

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.

Risk factors and outcome of contamination in patients on peritoneal dialysis--a single-center experience of 15 years

OBJECTIVE

Contamination is an important risk factor for peritoneal dialysis (PD)-related peritonitis. The present study outlines the clinical characteristics and outcomes of PD patients experiencing touch contamination.

METHODS

We reviewed the case records of PD patients from 1995 to 2010. Patients who experienced contamination of their PD system were identified and stratified into "dry" and "wet" contamination groups. Risk factors, microbiology, and clinical outcomes were compared.

RESULTS

Of 548 episodes of touch contamination, 246 involved dry contamination, and 302, wet contamination. After contamination, 17 episodes of peritonitis (3.1%) developed; all episodes occurred in the wet contamination group (p < 0.001). The incidence of peritonitis after wet contamination was 5.63%. Prophylactic antibiotics significantly reduced the risk of peritonitis (1 of 182 episodes, p < 0.001). Half the patients experiencing peritonitis had either culture-negative or staphylococcal episodes, and most of those episodes responded to intraperitoneal antibiotics. In 2 patients, peritonitis was attributable to Pseudomonas, and in 3, to Acinetobacter. In these latter patients, outcomes were less favorable, with catheter removal being required in 4 of the 5 episodes.

CONCLUSIONS

The overall rate of peritonitis was low after contamination. Wet contamination was associated with a much higher risk of peritonitis. Prophylactic antibiotics after wet contamination were effective in preventing peritonitis.

Risk factors associated with peritoneal dialysis catheter survival: a 9-year single-center study in 315 patients

PURPOSE

To review the peritoneal dialysis (PD) catheter outcomes at our center and assess factors affecting catheter survival.

METHODS

We carried out a retrospective study on 315 patients who had their first PD catheter placed between January 2001 and September 2009 at the UT Southwestern/DaVita Peritoneal Dialysis Clinic at Dallas, Texas. Medical records were reviewed for demographic and clinical information of the patients. The primary end point of the study was PD catheter failure, defined as removal of a dysfunctional PD catheter due to catheter-related complications. Catheter survival was estimated using the Kaplan-Meier method. Cox proportional hazard regression model was used to identify factors that are independently associated with catheter survival.

RESULTS

The mean age of the patients was 49.7 ± 29 yrs. The study population included 54.6% females, 42.5% African American, 27.9% Caucasian and 22.9% Hispanic patients. Diabetes was the primary etiology of end-stage renal disease in 43.2% of patients. More than 90% of patients had one or more co-morbidities, and 57.5% had previous abdominal surgery. The mean BMI for the group was 28.6 ± 13.8 kg/m2. Less than a quarter of the patients (24.1%) had non-infectious/mechanical catheter problems. Overall PD catheter survival rates over 12, 24 and 36 months were 92.9%, 91.9% and 91.1%, respectively. PD catheter-related non-infectious problem was the only independent variable that was significantly associated with catheter survival (hazard ratio 22.467; 95% CI 6.665-75.732). No significant association was observed between the PD catheter survival and other risk factors including age, body mass index (BMI), diabetic status, co-morbidities, previous abdominal surgeries or infections.

CONCLUSIONS

Our study shows an excellent 3-yr PD catheter survival (91.1%). Only PD catheter-related non-infectious problems are significantly associated with catheter failure. Other factors such as age, gender, race, BMI, diabetic status, co-morbidities, previous abdominal surgeries, peritoneal infections or exit site/tunnel infections were not found to affect the PD catheter survival and should not be considered barriers to PD initiation.

Repeat peritonitis in peritoneal dialysis: retrospective review of 181 consecutive cases

BACKGROUND AND OBJECTIVES

The clinical behavior of repeat-peritonitis episodes, defined as peritonitis with the same organism occurring more than 4 weeks after completion of therapy for a prior episode, is poorly understood.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We compared outcomes of 181 episodes of repeat peritonitis from 1995 to 2009 (Repeat Group) with 91 episodes of relapsing peritonitis (Relapsing Group) and 125 episodes of peritonitis preceded 4 weeks or longer by another episode with a different organism (Control Group).

RESULTS

In Repeat Group, 24% were due to Staphylococcus aureus, as compared with 5.5% in Relapsing Group and 15% in Control Group. The majority of the organisms causing relapsing peritonitis were Gram negative (62%), whereas the majority of that in Repeat Group were Gram positive (56%). Repeat Group had a lower complete-cure rate (70.7% versus 54.9%) than Relapsing Group, but rates of primary response, catheter removal, and mortality were similar. Repeat Group had a higher primary response rate (89.0% versus 73.6%) and a lower rate of catheter removal (6.1% versus 15.2%) than Control Group, whereas the complete-cure rate and mortality were similar. Repeat Group had a higher risk of developing relapsing (14.3% versus 2.2%) and repeat peritonitis (26.1% versus 5.4%) than Control Group, whereas the risk of recurrent peritonitis was similar.

CONCLUSIONS

Repeat peritonitis is a distinct clinical entity. Although repeat-peritonitis episodes generally have a satisfactory response to antibiotic, they have a substantial risk of developing further relapsing or repeat peritonitis.

The impact of treatment modality on infection-related hospitalization rates in peritoneal dialysis and hemodialysis patients

BACKGROUND AND OBJECTIVES

Infection is a major cause of morbidity and mortality in the dialysis population. This study compares the rates of infection-related hospitalization (IRH) in incident chronic dialysis patients initiating outpatient peritoneal dialysis (PD) and hemodialysis (HD).

METHODS AND PATIENTS

This was a retrospective cohort study at the dialysis program of a tertiary-care center in Toronto, Canada. Incident chronic dialysis patients that were eligible for both PD and HD and started outpatient dialysis between 1 January 2004 and 31 August 2008 were included. Dialysis modality was assigned at the start of outpatient dialysis treatment. All hospital admissions were reviewed and incidence of IRH was compared between PD and HD using Poisson regression.

RESULTS

Of 264 incident chronic dialysis patients, 168 (64%) were eligible for both treatment modalities: 71 (42%) started outpatient PD and 97 (58%) started outpatient HD. The unadjusted and adjusted incidence rate ratios (IRR) of IRH did not differ significantly between PD and HD: 1.23 [95% confidence interval (CI) 0.65-2.32, p=0.37] and 1.14 (95% CI 0.58-2.23, p=0.71) respectively. There was no difference between PD and HD in the risk of access loss (28% vs 35%, p=0.73), modality change (22% vs 0%, p=0.10), or death (17% vs 6%, p=0.60) following hospitalization for infection. Patients starting outpatient treatment on PD versus HD were more likely to be hospitalized for peritonitis (IRR 3.20, 95% CI 1.16-9.09; p=0.029) and there was a trend for fewer hospitalizations for bacteremia (IRR 0.19, 95% CI 0.028-1.30; p=0.091). The risk of IRH did not differ between PD and HD in the subgroup of patients that received adequate predialysis care (IRR 1.16, 95% CI 0.59-2.27; p=0.67) or when patients starting outpatient HD with a central venous catheter were excluded (IRR 1.52, 95% CI 0.53-4.37; p=0.44).

CONCLUSIONS

Patients that initiate outpatient peritoneal dialysis do not have a significantly increased risk of infection-related hospitalization compared to those that initiate outpatient hemodialysis.

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.