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.

Obesity, Weight Gain, and Fluid Overload in Peritoneal Dialysis

Obesity is a global epidemic that has a complicated pathogenesis as well as impact on the outcome of peritoneal dialysis (PD) patients. In this review, the prevalence of obesity in incident PD patients as well as the phenomenon of new-onset glucose intolerance after PD will be reviewed. Published literature on the effect of obesity on the survival and incidence of cardiovascular disease in PD patients will be discussed. Particular emphasis would be put on literature that compared the impact of obesity on the outcome of hemodialysis and PD, and the confounding effect of dialysis adequacy. Next, the complex concept of obesity and its relevance for PD will be explored. The focus would be put on the methods of assessment and clinical relevance of central versus general obesity, as well as visceral versus subcutaneous adipose tissue. The relation between obesity and systemic inflammation, as well as the biological role of several selected adipokines will be reviewed. The confounding effects of metabolic syndrome and insulin resistance will be discussed, followed by the prevalence and prognostic impact of weight gain during the first few years of PD. The differences between weight gain due to fluid overload and accumulation of adipose tissue will be discussed, followed by the current literature on the change in body composition after patients are put on chronic PD. The methods of body composition will be reviewed, and the clinical relevance of individual body component (fluid, fat, muscle, and bone) will be discussed. The review will conclude by highlighting current gaps of knowledge and further research directions in this area.

Two decades of analysis of peritonitis in peritoneal dialysis in Andalusia: Epidemiological, clinical, microbiological and progression aspects

BACKGROUND

This study focuses on the main complication associated with peritoneal dialysis, peritonitis. Its relevance derives from its high morbidity, the negative effect it has on the peritoneum as a dialysis membrane and its financial cost.

METHODS

Analytical, non-interventional, observational cohort study, whose main objective is the analysis of peritonitis in patients on peritoneal dialysis in Andalusia from 1 January 1999 to 31 December 2017, with a total of 2904 peritonitis cases. The database used is the Andalusian Autonomous Transplant Coordination Information System (SICATA).

OBJECTIVES

To ascertain how the rate of peritonitis is evolving in our community, analyse descriptive data pertaining to patients and peritonitis, ascertain the course of these infectious complications and analyse the factors that influence these cases of peritonitis and their outcomes: germ, hospitalisation and date.

RESULTS

The rate of peritonitis decreased progressively during the study period, from 0.7 peritonitis per patient in 1999 to 0.33 at the end of the period. Most infections were treated on an outpatient basis (72.5%). The most common germs were Gram-positive (55.9%), including coagulase-negative staphylococci (28.1%). Most cases of peritonitis progressed to healing (77.8%). The factors that significantly influence the need for hospitalisation and peritonitis progression were the causative germ and associated exit site infection.

CONCLUSIONS

In our population, the rate of peritonitis decreased progressively during the study period, meeting guideline recommendations.

Two decades of analysis of peritonitis in peritoneal dialysis in Andalusia: Epidemiological, clinical, microbiological and progression aspects

BACKGROUND

This study focuses on the main complication associated with peritoneal dialysis, peritonitis. Its relevance derives from its high morbidity, the negative effect it has on the peritoneum as a dialysis membrane and its financial cost.

METHODS

Analytical, non-interventional, observational cohort study, whose main objective is the analysis of peritonitis in patients on peritoneal dialysis in Andalusia from 1 January 1999 to 31 December 2017, with a total of 2,904 peritonitis cases. The database used is the Andalusian Autonomous Transplant Coordination Information System (SICATA).

OBJECTIVES

To ascertain how the rate of peritonitis is evolving in our community, analyse descriptive data pertaining to patients and peritonitis, ascertain the course of these infectious complications and analyse the factors that influence these cases of peritonitis and their outcomes: germ, hospitalisation and date.

RESULTS

The rate of peritonitis decreased progressively during the study period, from 0.7 peritonitis per patient in 1999 to 0.33 at the end of the period. Most infections were treated on an outpatient basis (72.5%). The most common germs were Gram-positive (55.9%), including coagulase-negative staphylococci (28.1%). Most cases of peritonitis progressed to healing (77.8%). The factors that significantly influence the need for hospitalisation and peritonitis progression were the causative germ and associated exit site infection.

CONCLUSIONS

In our population, the rate of peritonitis decreased progressively during the study period, meeting guideline recommendations.

Nontuberculous mycobacteria infections of peritoneal dialysis patients: A multicenter study

OBJECTIVES

Nontuberculous mycobacteria (NTM) infections pose a diagnostic challenge in peritoneal dialysis (PD) patients. In this study, we sought to identify findings that are suggestive of NTM infection in PD adult patients.

METHODS

All patients with NTM exit-site infection (ESI) with/without tunnel infection and peritonitis identified during the last decade in eight medical centers in Israel were included. Clinical, microbiological, and outcome data were collected and analyzed.

RESULTS

Thirty patients were identified; 16 had ESI (53%) and 14 had peritonitis (47%). Median age was 65 years (interquartile range 52-76). Abdominal pain and cloudy PD fluid were reported in all patients with peritonitis, whereas exit-site discharge and granulation tissue were common in patients with ESI. Fourteen patients (47%) had negative cultures prior NTM diagnosis, and isolation of diphtheroids or Corynebacterium spp. was reported in 9 of 30 patients (30%). Antimicrobial treatment prior to diagnosis was documented in 13 of 30 patients (43%). Delayed diagnosis was frequent. Treatment regimens and duration of therapy varied widely. In 26 of 30 (87%) patients, catheter was removed and 19 of 30 patients (63%) required permanent transition to hemodialysis. Two patients with peritonitis (2 of 14, 14%) and seven with ESI (7 of 16, 44%) were eligible for continuation of PD.

CONCLUSIONS

Culture negative peritonitis, isolation of diphtheroids or Corynebacterium spp., previous exposure to antibiotics, and/or a refractory infection should all prompt consideration of PD-related NTM infection and timely workup. Catheter removal is recommended aside prolonged antimicrobial therapy. In select patients with ESI, continuation of PD may be feasible.

Predictive value of procalcitonin for infection of patients with type-2 diabetes mellitus

The aim of the present study was to investigate the predictive value of procalcitonin (PCT) for infection in patients with type 2 diabetes mellitus (T2DM). A retrospective analysis of 178 patients with T2DM who were divided into non-infection, local infection and sepsis groups was conducted; in conjunction with 33 healthy control patients. Clinicopathological characteristics and inflammatory indicators were compared between the four groups. Patients in the non-infection group exhibited significantly higher PCT levels compared with healthy controls (P=0.002). In addition, PCT, C-reactive protein (CRP), white blood cell count and neutrophil percent were significantly different amongst patients with T2MD across different infection groups (all P<0.001) with the following rank order: Sepsis group > local infection group > non-infection group (all P<0.05). In addition, the following observations were made: i) PCT and CRP demonstrated larger areas under the curve (AUC) for predicting local infection (0.804 and 0.741, respectively); ii) PCT displayed lower sensitivity of only 21.8% at its classical cutoff value (0.500 ng/ml) whereas CRP exhibited higher sensitivity and specificity at 64.1 and 76.1%, respectively, at its classical cutoff value (10.0 mg/l); and iii) PCT exhibited the largest AUC (0.914) for predicting sepsis with high sensitivity and specificity (86.4 and 84.5%, respectively) at its cutoff value (0.990 ng/ml). Patients with T2DM without infection demonstrated higher baseline PCT levels. The present study clarified the value of PCT in predicting infection of T2DM patients. The application of PCT to predict local infection in patients with T2DM was identified to be inferior to CRP, but its ability to predict sepsis was concluded to be the best when compared with CRP, white blood cell count and neutrophil percent.

Successful treatment of peritoneal dialysis-related peritonitis caused by Dermacoccus nishinomiyaensis

A 53-year-old man receiving peritoneal dialysis (PD) for 4 months presented with PD-related peritonitis (abdominal pain, turbid peritoneal dialysate effluent, white blood cell in peritoneal dialysate effluent 5350/µL, C-reactive protein 25.56 mg/dL) caused by Dermacoccus (D.) nishinomiyaensis. He was first treated empirically with cefazolin and ceftazidime. After detection of D. nishinomiyaensis in the peritoneal effluent culture collected on the first day of hospitalization, the antibiotics were changed to amoxicillin and vancomycin. After confirming negative-conversion of peritoneal effluent culture, treatment was continued for more than 6 weeks. The peritonitis resolved; he continues peritoneal dialysis without withdrawal from PD or catheter removal. D. nishinomiyaensis is part of resident microbiota of the skin, and its pathogenicity is rarely reported. To date, there is no report of PD-related peritonitis caused by D. nishinomiyaensis. Because it is a slow grower, it may be missed and the peritonitis categorized as culture-negative. Long-term culture is important to detect it. It is difficult to determine the antibiotics that can be used because susceptibility to antibiotics is unknown due to the organism's rarity. Furthermore, the appropriate treatment period is also unknown. Long-term treatment may be useful in PD-related peritonitis caused by D. nishinomiyaensis because it is a slow grower.

Steady-State Pharmacokinetics of Oral Ciprofloxacin in Continuous Cycling Peritoneal Dialysis Patients: Brief Report

Steady-state pharmacokinetics of oral ciprofloxacin in 3 continuous cycling peritoneal dialysis (CCPD) outpatients given ciprofloxacin 750 mg b.i.d. for 5 doses was determined. Mean steady-state maximum serum concentration and half-life were 4.4 ± 1.5 mg/L and 10.3 ± 2.6 hours, respectively. Mean maximum dialysate concentration in the daytime long dwell and overnight continuous cycling dwell were 7.4 ± 1.2 mg/L and 3.3 ± 1.2 mg/L, respectively. Oral ciprofloxacin 750 mg b.i.d. may be reasonable for bloodstream and peritoneal infections caused by susceptible bacteria in CCPD patients.

The effect of far infrared radiation therapy on inflammation regulation in lipopolysaccharide-induced peritonitis in mice

Objective:

Far infrared radiation has been widely used in a variety of healthcare institutions and clinical research. Previous studies have shown that far infrared radiation can promote blood circulation and enhance the functioning of the immune system. Many patients receiving peritoneal dialysis have been co-treated with far infrared radiation to reduce the occurrence of inflammation. This study seeks to evaluate the effects of far infrared radiation therapy on inflammation.

Method:

We used the lipopolysaccharide-induced peritonitis mouse model to study the effect of far infrared radiation treatment. Sixteen mice were randomly divided into two groups, a far infrared radiation treatment group (n = 8) and a non-far infrared radiation treatment group (n = 8). Collected blood samples were studied by analyzing the RNA level of peripheral blood mononuclear cells and the plasma protein levels of interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), and endothelial nitric oxide synthase (eNOS).

Results:

The administration of far infrared radiation inhibited the RNA levels of interleukin-6 and TNF-α after stimulation by lipopolysaccharide. The far infrared radiation treatment inhibited the endothelial nitric oxide synthase RNA levels at 1 h, but the RNA levels returned close to the baseline level after 2 h. In the control group, the endothelial nitric oxide synthase RNA levels were continuously decreasing. The interleukin-6 concentration in the plasma of the far infrared radiation group showed significant inhibition 30 min after lipopolysaccharide stimulation. The tumor necrosis factor alpha RNA concentration in plasma of the far infrared radiation group was significantly reduced 2 h after lipopolysaccharide stimulation.

Conclusion:

Far infrared radiation therapy can inhibit interleukin-6 and tumor necrosis factor alpha RNA levels of peripheral blood mononuclear cells and recover endothelial nitric oxide synthase expression. These results demonstrate that far infrared radiation therapy might aid in reducing the level of inflammation experienced by patients going through peritoneal dialysis treatment.

Center Effects and Peritoneal Dialysis Peritonitis Outcomes: Analysis of a National Registry

BACKGROUND

Peritonitis is a common cause of technique failure in peritoneal dialysis (PD). Dialysis center-level characteristics may influence PD peritonitis outcomes independent of patient-level characteristics.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

Using Australia and New Zealand Dialysis and Transplant Registry (ANZDATA) data, all incident Australian PD patients who had peritonitis from 2004 through 2014 were included.

PREDICTORS

Patient- (including demographic data, causal organisms, and comorbid conditions) and center- (including center size, proportion of patients treated with PD, and summary measures related to type, cause, and outcome of peritonitis episodes) level predictors.

OUTCOMES & MEASUREMENT

The primary outcome was cure of peritonitis with antibiotics. Secondary outcomes were peritonitis-related catheter removal, hemodialysis therapy transfer, peritonitis relapse/recurrence, hospitalization, and mortality. Outcomes were analyzed using multilevel mixed logistic regression.

RESULTS

The study included 9,100 episodes of peritonitis among 4,428 patients across 51 centers. Cure with antibiotics was achieved in 6,285 (69%) peritonitis episodes and varied between 38% and 86% across centers. Centers with higher proportions of dialysis patients treated with PD (>29%) had significantly higher odds of peritonitis cure (adjusted OR, 1.21; 95% CI, 1.04-1.40) and lower odds of catheter removal (OR, 0.78; 95% CI, 0.62-0.97), hemodialysis therapy transfer (OR, 0.78; 95% CI, 0.62-0.97), and peritonitis relapse/recurrence (OR, 0.68; 95% CI, 0.48-0.98). Centers with higher proportions of peritonitis episodes receiving empirical antibiotics covering both Gram-positive and Gram-negative organisms had higher odds of cure with antibiotics (OR, 1.22; 95% CI, 1.06-1.42). Patient-level characteristics associated with higher odds of cure were younger age and less virulent causative organisms (coagulase-negative staphylococci, streptococci, and culture negative). The variation in odds of cure across centers was 9% higher after adjustment for patient-level characteristics, but 66% lower after adjustment for center-level characteristics.

LIMITATIONS

Retrospective study design using registry data.

CONCLUSIONS

These results suggest that center effects contribute substantially to the appreciable variation in PD peritonitis outcomes that exist across PD centers within Australia.

Effect of UV Light on Disinfection of Peritoneal Dialysis Catheter Connections

We evaluated the microbiological performance of an ultraviolet (UV) light-based peritoneal dialysis catheter connection system. The system includes a UV light-generating device combined with a UV transmissive window incorporated into the transfer set. Each UV transparent transfer set was inoculated with 10 μL of cultured inoculum consisting of either S. aureus, E. coli, or C. albicans After being inoculated, we attached a solution set connector to the transfer catheter, and exposed that connection to a UV light dose of approximately 340 mJoules/cm² After exposure to UV light, we broke the seal of the solution set and opened the plunger valve on the UV transmissive transfer catheter. We then flushed 10 mL of dialysate through the connection. The flushed solution was collected, diluted, plated on agar medium, and incubated for 24 hours. Results were compared to positive controls collected in an identical manner without exposure to UV light. Thirty test samples and 3 positive controls were collected for each organism. All test samples exposed to UV light had complete kill of bacteria except 1 colony on a single plate in the S. aureus group. Mean log reduction was 4.03 for C. albicans, 4.73 for S. aureus, and 5.29 for E. coli All positive control samples had significant bacterial growth. Our results demonstrate that the application of UV light within a UV transmissive transfer catheter window produces a germicidal effect upon microorganisms known to be associated with peritonitis.

High Levels of Soluble C5b-9 Complex in Dialysis Fluid May Predict Poor Prognosis in Peritonitis in Peritoneal Dialysis Patients

BACKGROUND

We searched for indicators to predict the prognosis of infectious peritonitis by measuring levels of complement proteins and activation products in peritoneal dialysis (PD) fluid (PDF) of patients at early stages of peritonitis. We retrospectively analyzed the relationship between the levels of sC5b-9, C3 and C4 in PDF and the subsequent clinical prognosis.

METHODS

We measured levels of sC5b-9, C3 and C4 in PDF on days 1, 2 and 5 post-onset of peritonitis in 104 episodes of infectious peritonitis in PD patients from 2008 and retrospectively compared levels with clinical outcomes. Further analysis for the presence of causative microorganisms or to demonstrate bacterial culture negative peritonitis was performed and correlated with change of levels of sC5b-9 in PDF.

RESULTS

When PD patients with peritonitis were divided into groups that either failed to recover from peritonitis and were finally withdrawn from PD (group 1; n = 25) or recovered (group 2; n = 79), levels of sC5b-9, C3 and C4 in PDF were significantly higher in group 1 patients compared to those in group 2 on day5. Analysis of microorganisms showed significantly higher sC5b-9 levels in PDF of peritonitis cases caused by culture negative peritonitis in group 1 compared with group 2 when we analyzed for individual microorganisms. Of note, on day5, the sC5b-9 levels in PDF were similarly high in peritonitis caused by fungi or other organisms.

CONCLUSION

Our results suggested that levels of complement markers in PDF, especially sC5b-9, have potential as surrogate markers to predict prognosis of PD-related peritonitis.

Age-Related Differences of Organism-Specific Peritonitis Rates: A Single-Center Experience

Peritonitis remains an important cause of morbidity and mortality in peritoneal dialysis (PD) patients, but its incidence and the distribution of causative organisms vary widely between institutions and age groups. This study was performed to investigate the recent status and risk factors of PD-related peritonitis and to clarify differences between age groups. We retrospectively reviewed the medical records of 119 PD patients treated at our department between January 2002 and January 2013. We calculated both overall and organism-specific peritonitis rates and also analyzed risk factors. Sixty-three episodes of peritonitis occurred during 261.5 patient-years for an incident rate of 0.24 episodes/patient-year. Multivariate analysis showed that older age (≥65 years) and hypoalbuminemia (<3.0 g/dL) were associated with an increased risk of peritonitis (P = 0.035 and P = 0.029, respectively). In elderly patients (≥65 years old), the rate of peritonitis due to Gram-positive and Gram-negative bacteria was 0.17 and 0.08 episodes/patient-year, respectively, and Gram-positive peritonitis was markedly more frequent than in younger patients (<65 years old). In particular, there was a high frequency of Staphylococcus aureus peritonitis in elderly patients (0.09 episodes/patient-year) and it had a poor outcome. At our department, the risk of peritonitis was increased in older patients and patients with hypoalbuminemia. The distribution of causative organisms was markedly different between age groups and analysis of organism-specific peritonitis rates helped to identify current problems with our PD program.

Peritoneal dialysis: An effective yet underused renal replacement therapy

Chronic kidney disease affects more than 30 million people in the United States, creating a significant disease burden. Peritoneal dialysis, an effective yet underused method of renal replacement therapy, can provide a high quality of life, maintain a patient's residual renal function, and decrease overall healthcare costs with little negative effect on patient morbidity or mortality. Given this, knowledge of the methods, outcomes, and costs of renal replacement therapy is essential to physician assistants.

Recent analysis of status and outcomes of peritoneal dialysis in the Tokai area of Japan: the second report of the Tokai peritoneal dialysis registry

BACKGROUND

Early withdrawal within 3 years after starting peritoneal dialysis (PD) and PD-related peritonitis have been major obstacles preventing increases in the population of PD patients. To address these problems, we implemented education programs for medical staff. This study analyzed the recent status and outcomes of PD therapy, focusing on findings such as the incidence and prognosis of peritonitis as of 5 years after our last study.

METHODS

We investigated background, laboratory data and status of PD therapy, reasons for withdrawal from PD and incidental statements on peritonitis from 2010 to 2012 (R2), and compared findings with those from our last study of 2005-2007 (R1).

RESULTS

Early PD therapy withdrawal in R2 clearly improved to 44.7 %, compared with 50.9 % in R1. Peritonitis incidence improved slightly from once per 42.8 months/patient in R1 to once per 47.3 months/patient in R2. Notably, PD-related peritonitis as a cause of mortality improved markedly in R2, but outcomes of PD-related peritonitis did not change significantly between R1 and R2. In contrast, social problems increased as a reason for withdrawal from PD therapy.

CONCLUSION

Our efforts at education might have been useful for improving early withdrawal from PD and deaths attributable to PD-related peritonitis. However, since improvements to incidence of PD-related peritonitis were limited by education, further improvement in PD-related peritonitis incidence requires development of new sterilized connecting systems during PD-bag exchanges to decrease PD-related peritonitis opportunities. Construction of medical support systems to address social problems is required to maintain long-term PD therapy.

Paper and flexible substrates as materials for biosensing platforms to detect multiple biotargets

The need for sensitive, robust, portable, and inexpensive biosensing platforms is of significant interest in clinical applications for disease diagnosis and treatment monitoring at the point-of-care (POC) settings. Rapid, accurate POC diagnostic assays play a crucial role in developing countries, where there are limited laboratory infrastructure, trained personnel, and financial support. However, current diagnostic assays commonly require long assay time, sophisticated infrastructure and expensive reagents that are not compatible with resource-constrained settings. Although paper and flexible material-based platform technologies provide alternative approaches to develop POC diagnostic assays for broad applications in medicine, they have technical challenges integrating to different detection modalities. Here, we address the limited capability of current paper and flexible material-based platforms by integrating cellulose paper and flexible polyester films as diagnostic biosensing materials with various detection modalities through the development and validation of new widely applicable electrical and optical sensing mechanisms using antibodies and peptides. By incorporating these different detection modalities, we present selective and accurate capture and detection of multiple biotargets including viruses (Human Immunodeficieny Virus-1), bacteria (Escherichia coli and Staphylococcus aureus), and cells (CD4⁺ T lymphocytes) from fingerprick volume equivalent of multiple biological specimens such as whole blood, plasma, and peritoneal dialysis effluent with clinically relevant detection and sensitivity.

Syndecan-1 in the mouse parietal peritoneum microcirculation in inflammation

Background

The heparan sulfate proteoglycan syndecan-1 (CD138) was shown to regulate inflammatory responses by binding chemokines and cytokines and interacting with adhesion molecules, thereby modulating leukocyte trafficking to tissues. The objectives of this study were to examine the expression of syndecan-1 and its role in leukocyte recruitment and chemokine presentation in the microcirculation underlying the parietal peritoneum.

Methods

Wild-type BALB/c and syndecan-1 null mice were stimulated with an intraperitoneal injection of Staphylococcus aureus LTA, Escherichia coli LPS or TNFα and the microcirculation of the parietal peritoneum was examined by intravital microscopy after 4 hours. Fluorescence confocal microscopy was used to examine syndecan-1 expression in the peritoneal microcirculation using fluorescent antibodies. Blocking antibodies to adhesion molecules were used to examine the role of these molecules in leukocyte-endothelial cell interactions in response to LTA. To determine whether syndecan-1 co-localizes with chemokines in vivo, fluorescent antibodies to syndecan-1 were co-injected intravenously with anti-MIP-2 (CXCL2), anti-KC (CXCL1) or anti-MCP-1 (CCL2).

Results and Conclusion

Syndecan-1 was localized to the subendothelial region of peritoneal venules and the mesothelial layer. Leukocyte rolling was significantly decreased with LPS treatment while LTA and TNFα significantly increased leukocyte adhesion compared with saline control. Leukocyte-endothelial cell interactions were not different in syndecan-1 null mice. Antibody blockade of β₂ integrin (CD18), ICAM-1 (CD54) and VCAM-1 (CD106) did not decrease leukocyte adhesion in response to LTA challenge while blockade of P-selectin (CD62P) abrogated leukocyte rolling. Lastly, MIP-2 expression in the peritoneal venules was not dependent on syndecan-1 in vivo. Our data suggest that syndecan-1 is expressed in the parietal peritoneum microvasculature but does not regulate leukocyte recruitment and is not necessary for the presentation of the chemokine MIP-2 in this tissue.

Predictors for and impact of high peritonitis rate in Taiwanese continuous ambulatory peritoneal dialysis patients

AIM

The influence of high peritonitis rate (HPR) on clinical outcomes of continuous ambulatory peritoneal dialysis (CAPD) patients has been far less studied in the Chinese population than in those of the USA, Australia and Europe. Furthermore, concerning the peritonitis risk, most studies primarily examined the risk of developing the first peritonitis episode, rather than a HPR.

METHODS

A single-center, retrospective, observational study was carried out over 10 years in Taiwan. A total of 124 patients with at least one peritonitis episode were the study subjects. The Cox proportional hazard model was used to assess the impact of HPR on clinical outcomes. Multivariate logistic regression was conducted to determine the independent factors associated with a HPR.

RESULTS

In the multivariate Cox regression model, HPR was still a significant predictor for technique failure, patient mortality and dropout from peritoneal dialysis (PD). Factors independently associated with a HPR were peritonitis occurrence during the first year after the start of CAPD and the first peritonitis infected with streptococcus species.

CONCLUSION

Peritonitis during the first year after PD commencement and the first peritonitis infected by streptococcus species were significantly associated with an increased risk of a HPR. Our data also indicate that HPR was correlated with technique failure, patient mortality and dropout from PD, thus highlighting the need and role of future studies to reduce this complication.

Rat adipose tissue-derived stem cells attenuate peritoneal injuries in rat zymosan-induced peritonitis accompanied by complement activation

BACKGROUND AIMS

In patients receiving peritoneal dialysis, fungal or yeast peritonitis has a poor prognosis. In rat peritoneum with mechanical scraping, severe peritonitis can be induced by zymosan, a component of yeast (Zy/scraping peritonitis). Administration of rat adipose tissue-derived stromal cells (ASCs) potentially can improve several tissue injuries. The present study investigated whether rat ASCs could improve peritoneal inflammation in Zy/scraping peritonitis.

METHODS

Rat ASCs were injected intraperitoneally on a daily basis in rats with Zy/scraping peritonitis.

RESULTS

Peritoneal inflammation accompanied by accumulation of inflammatory cells and complement deposition was suppressed by day 5 after injection of rat ASCs. The peritoneal mesothelial layer in Zy/scraping peritonitis with rat ASC treatment was restored compared with the peritoneal mesothelial layer without rat ASC treatment. Injected rat ASCs co-existed with mesothelial cells in the sub-peritoneal layer. In vitro assays showed increased cellular proliferation of rat mesothelial cells combined with rat ASCs by co-culture assays, confirming that fluid factors from rat ASCs might play some role in facilitating the recovery of rat mesothelial cells. Hepatocyte growth factor was released from rat ASCs, and administration of recombinant hepatocyte growth factor increased rat mesothelial cell proliferation.

CONCLUSIONS

Because the peritoneal mesothelium shows strong expression of membrane complement regulators such as Crry, CD55 and CD59, restoration of the mesothelial cell layer by rat ASCs might prevent deposition of complement activation products and ameliorate peritoneal injuries. This study suggests the therapeutic possibilities of intraperitoneal rat ASC injection to suppress peritoneal inflammation by restoring the mesothelial layer and decreasing complement activation in fungal or yeast peritonitis.

Anti-C5a complementary peptide ameliorates acute peritoneal injury induced by neutralization of Crry and CD59

In peritoneal dialysis (PD) therapy, physical stresses such as exposure to peritoneal dialysate, catheter trauma, and peritonitis may induce peritoneal injury that can prevent continued long-term PD therapy. Therefore, protection of the peritoneum is an important target to enable long-term PD therapy in patients with end-stage renal disease. We previously showed that neutralization of the membrane complement regulators (CRegs) Crry and CD59 in rat peritoneum provokes development of acute peritoneal injury due to uncontrolled complement activation. C5a is a key effecter molecule of the complement system released during acute inflammation. Control of C5a has been proposed as a strategy to suppress inflammatory reactions and, because peritoneal injury is accompanied by inflammation, we hypothesized that C5a targeted therapy might be an effective way to suppress peritoneal injury. In the present study we used an established acute peritonitis model induced by neutralization of CRegs to investigate the effects on acute peritoneal injury of inhibiting C5a. Intravenous administration of an anti-C5a complementary peptide (AcPepA) up to 4 h after induction of injury significantly and dose-dependently prevented accumulation of inflammatory cells and reduced tissue damage in the model, accompanied by decreased C3b deposition. We show that C5a contributed to the development of peritoneal injury. Our results suggest that C5a is a target for preventing or treating peritoneal injury in patients undergoing prolonged PD therapy or with infectious complications.

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.

Perforative peritonitis caused by appendicitis in a patient on peritoneal dialysis

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

Diagnostic value of serum procalcitonin in patients with chronic renal insufficiency: a systematic review and meta-analysis

BACKGROUND

The diagnostic value of procalcitonin (PCT) for patients with renal impairment is unclear.

METHODS

We searched multiple databases for studies published through December 2011 that evaluated the diagnostic performance of PCT among patients with renal impairment and suspected systemic bacterial infection. We summarized test performance characteristics with the use of forest plots, hierarchical summary receiver operating characteristic (HSROC) curves, and bivariate random effects models.

RESULTS

Our search identified 201 citations, of which seven diagnostic studies evaluated 803 patients and 255 bacterial infection episodes. HSROC-bivariate pooled sensitivity estimates were 73% [95% confidence interval (95% CI) 54-86%] for PCT tests and 78% (95% CI 52-92%) for CRP tests. Pooled specificity estimates were higher for both PCT and CRP tests [PCT, 88% (95% CI 79-93%); CRP, 84% (95% CI, 52-96%)]. The positive likelihood ratio for PCT [likelihood (LR)+ 6.02, 95% CI 3.16-11.47] was sufficiently high to be qualified as a rule-in diagnostic tool, while the negative likelihood ratio was not low enough to be used as a rule-out diagnostic tool (LR- 0.31, 95% CI 0.17-0.57). There was no consistent evidence that PCT was more accurate than CRP test for the diagnosis of systemic infection among patients with renal impairment.

CONCLUSIONS

Both PCT and CRP tests have poor sensitivity but acceptable specificity in diagnosing bacterial infection among patients with renal impairment. Given the poor negative likelihood ratio, its role as a rule-out test is questionable.

Using a multidisciplinary training program to reduce peritonitis in peritoneal dialysis patients

OBJECTIVES

The present study evaluated the tool used to assess patients' skills and the impact on peritonitis rates of a new multidisciplinary peritoneal dialysis (PD) education program (PDEP).

METHODS

After the University Hospital Ethics Committee approved the study, the educational and clinical records of PD patients were retrospectively analyzed in two phases. In phase I, an Objective Structured Assessment (OSA) was used during August 2008 to evaluate the practical skills of 25 patients with adequate Kt/V and no mental disabilities who had been on PD for more than 1 month. Test results were correlated with the prior year's peritonitis rate. In phase II, the new PDEP, consisting of individual lessons, a retraining schedule, and group meetings, was introduced starting 1 September 2008. Age, sex, years of education, time on PD, number of training sessions, and peritonitis episodes were recorded. Statistical analyses used t-tests, chi-square tests, and Poisson distributions; a p value of less than 0.05 was considered significant.

RESULTS

In phase I, 25 patients [16 men, 9 women; mean age: 54 ± 15 years (range: 22 - 84 years); mean time on PD: 35 ± 30 months (range: 1 - 107 months)] were studied. The OSA results correlated with peritonitis rates: patients who passed the test had experienced significantly lower peritonitis rates during the prior year (p < 0.05). In phase II, after the new PDEP was introduced, overall peritonitis rates significantly declined (to 0.28 episodes/patient-year from 0.55 episodes/patient-year, p < 0.05); the Staphylococcus peritonitis rate also declined (to 0.09 episodes/patient-year from 0.24 episodes/patient-year, p < 0.05).

CONCLUSIONS

The OSA is a reliable tool for assessing patients' skills, and it correlates with peritonitis rates. The multidisciplinary PDEP significantly improved outcomes by further lowering peritonitis rates.

In vitro microbiology studies on a new peritoneal dialysis connector

OBJECTIVE

We evaluated the ability of a recently developed peritoneal dialysis (PD) connector to prevent the risk of bacterial transfer to the fluid path after simulated touch and airborne contamination.

METHODS

Staphylococcus epidermidis ATCC1228 and Pseudomonas aeruginosa ATCC27853 strains were used. For touch contamination, 2 μL of a standardized inoculum [1×10(8) colony-forming units (CFU) per milliliter] were deposited on top of the pin closing the fluid path of the patient connector. For airborne contamination, the patient connector was exposed for 15 seconds to a nebulized standardized inoculum. To simulate the patient peritoneum and effluent, the patient connector was pre-attached to a 2-L bag of sterile PD solution. After contamination, the patient connector was attached to the transfer set, the pin was captured, flow control was turned to simulate "patient drain" into the empty bag, and then "patient fill" using the bag pre-attached to the connector. Finally, a new pin was recaptured. The PD solution collected in the bag pre-attached to the connector was run through a 0.20-μm filter for colony counts.

RESULTS

No infected connector transferred bacteria to the fluid path, regardless of the challenge procedure or the strain used.

CONCLUSIONS

Our results show that the new PD connector may fully obviate the risk of bacterial infection, even in the presence of heavy contamination. Further studies are in progress to test our PD connector in a clinical setting.

Asymptomatic diverticulosis identified by computed tomography is not a risk factor for enteric peritonitis

BACKGROUND

Colonic diverticulitis is an important cause of polymicrobial peritonitis, which requires surgical treatment and cessation of peritoneal dialysis (PD). The aim of this study was to examine whether plain abdominal computed tomography (CT) is useful for evaluating colonic diverticulosis in chronic kidney disease (CKD) patients and to explore whether colonic diverticulosis is a risk factor for enteric peritonitis.

METHODS

The subjects consisted of 137 consecutive CKD patients (Stage 4 or 5) who were candidates for PD from February 2005 to November 2009. Abdominal CT without contrast media was performed in all PD candidates.

RESULTS

Diverticula of the colon were detected by plain CT in 57 cases (41.6%). The number of diverticula tended to increase with age. The most common site of involvement of diverticulosis was the ascending colon. In patients treated with PD, the incidence of peritonitis was higher in patients with diverticulosis than in those without diverticulosis (P = 0.004). However, only one episode of enteric peritonitis was observed among patients with diverticulosis. The presence of diverticulosis did not affect cumulative or technical survival. PD was not selected in four cases due to a high frequency of diverticula with episodes of abdominal pain. Two cases developed severe diverticulitis with peritonitis and underwent resection of the colon.

CONCLUSIONS

Our study suggests that plain CT examination is useful for detecting diverticulosis in CKD patients. Silent diverticulosis is not a risk factor for enteric diverticulosis-related peritonitis. PD may be contraindicated in cases having frequent diverticulosis with episodes of lower abdominal pain.

Peritoneal dialysis-associated nontuberculous mycobacterium peritonitis: a systematic review of reported cases

BACKGROUND

Peritonitis caused by nontuberculous mycobacterium (NTM) is an important complication in peritoneal dialysis (PD) patients.

METHODS

Cases of PD complicated by NTM peritonitis reported in the English language literature were identified in the PubMed database. The characteristics of these cases were reviewed.

RESULTS

In 41 articles, we identified 57 cases of PD-associated NTM peritonitis in patients ranging from 5 to 82 years. The prevalent clinical findings of these cases were fever, abdominal pain, cloudy fluid and an elevated leukocyte count in peritoneal fluid. These findings were non-specific and could not be differentiated from symptoms caused by Mycobacterium tuberculosis or other bacteria. The majority of these cases received empirical antibacterial therapy before diagnosis of NTM peritonitis. Isolates in more than half of the peritonitis cases were the rapidly growing Mycobacterium, Mycobacterium fortuitum (38.6%) and Mycobacterium chelonae (14.0%). In most cases, PD catheters were removed and experience with non-removal was limited.

CONCLUSION

Diagnosis of NTM infection should be considered in PD patients with peritonitis that are culture negative or refractory to empirical antibiotic therapy.

A case of perforative peritonitis caused by a piece of bamboo in a patient on peritoneal dialysis

We report a case of peritonitis resulting from colon perforation caused by ingestion of a rare foreign body in a patient on peritoneal dialysis (PD). A 72-year-old woman on PD was hospitalized with abdominal pain and cloudy PD fluid (PDF). Although conventional antibiotic therapy was started because of a diagnosis of infectious peritonitis, low-grade fever, abdominal pain and a high number of white blood cells in PDF persisted. On day 3, anaerobic bacteria were recognized on bacterial culture of PDF, suggesting a gastrointestinal etiology. During exploratory laparotomy, sigmoidal perforation by a piece of bamboo, probably resulting from ingestion of contaminated food, was found.