Variation in Peritoneal Dialysis-Related Peritonitis Outcomes in the Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS).

RATIONALE & OBJECTIVE: Peritoneal dialysis (PD)-associated peritonitis is a significant PD-related complication. We describe the likelihood of cure after a peritonitis episode, exploring its association with various patient, peritonitis, and treatment characteristics. STUDY DESIGN: Observational prospective cohort study. SETTING & PARTICIPANTS: 1,631 peritonitis episodes (1,190 patients, 126 facilities) in Australia, New Zealand, Canada, Japan, Thailand, the United Kingdom, and the United States. EXPOSURE: Patient characteristics (demographics, patient history, laboratory values), peritonitis characteristics (organism category, concomitant exit-site infection), dialysis center characteristics (use of icodextrin and low glucose degradation product solutions, policies regarding antibiotic self-administration), and peritonitis treatment characteristics (antibiotic used). OUTCOME: Cure, defined as absence of death, transfer to hemodialysis (HD), PD catheter removal, relapse, or recurrent peritonitis within 50 days of a peritonitis episode. ANALYTICAL APPROACH: Mixed-effects logistic models. RESULTS: Overall, 65% of episodes resulted in a cure. Adjusted odds ratios (AOR) for cure were similar across countries (range, 54%-68%), by age, sex, dialysis vintage, and diabetes status. Compared with Gram-positive peritonitis, the odds of cure were lower for Gram-negative (AOR, 0.41 [95% CI, 0.30-0.57]), polymicrobial (AOR, 0.30 [95% CI, 0.20-0.47]), and fungal (AOR, 0.01 [95% CI, 0.00-0.07]) peritonitis. Odds of cure were higher with automated PD versus continuous ambulatory PD (AOR, 1.36 [95% CI, 1.02-1.82]), facility icodextrin use (AOR per 10% greater icodextrin use, 1.06 [95% CI, 1.01-1.12]), empirical aminoglycoside use (AOR, 3.95 [95% CI, 1.23-12.68]), and ciprofloxacin use versus ceftazidime use for Gram-negative peritonitis (AOR, 5.73 [95% CI, 1.07-30.61]). Prior peritonitis episodes (AOR, 0.85 [95% CI, 0.74-0.99]) and concomitant exit-site infection (AOR, 0.41 [95% CI, 0.26-0.64]) were associated with a lower odds of cure. LIMITATIONS: Sample selection may be biased and generalizability may be limited. Residual confounding and confounding by indication limit inferences. Use of facility-level treatment variables may not capture patient-level treatments. CONCLUSIONS: Outcomes after peritonitis vary by patient characteristics, peritonitis characteristics, and modifiable peritonitis treatment practices. Differences in the odds of cure across infecting organisms and antibiotic regimens suggest that organism-specific treatment considerations warrant further investigation.

International peritoneal dialysis training practices and the risk of peritonitis.

BACKGROUND: The effects of training practices on outcomes of patients receiving peritoneal dialysis (PD) are poorly understood and there is a lack of evidence informing best training practices. This prospective cohort study aims to describe and compare international PD training practices and their association with peritonitis. METHODS: Adult patients on PD <3 months participating in the Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS) were included. Training characteristics (including duration, location, nurse affiliation, modality, training of family members, use of individual/group training and use of written/oral competency assessments) were reported at patient and facility levels. The hazard ratio (HR) for time to first peritonitis was estimated using Cox models, adjusted for selected patient and facility case-mix variables. RESULTS: A total of 1376 PD patients from 120 facilities across seven countries were included. Training was most commonly performed at the facility (81%) by facility-affiliated nurses (87%) in a 1:1 setting (79%). In the UK, being trained by both facility and third-party nurses was associated with a reduced peritonitis risk [adjusted HR 0.31 (95% confidence interval 0.15-0.62) versus facility nurses only]. However, this training practice was utilized in only 5 of 14 UK facilities. No other training characteristics were convincingly associated with peritonitis risk. CONCLUSIONS: There was no evidence to support that peritonitis risk was associated with when, where, how or how long PD patients are trained.

Peritoneal Dialysis-Related Infection Rates and Outcomes: Results From the Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS).

RATIONALE & OBJECTIVE: Peritoneal dialysis (PD)-related peritonitis carries high morbidity for PD patients. Understanding the characteristics and risk factors for peritonitis can guide regional development of prevention strategies. We describe peritonitis rates and the associations of selected facility practices with peritonitis risk among countries participating in the Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS). STUDY DESIGN: Observational prospective cohort study. SETTING & PARTICIPANTS: 7,051 adult PD patients in 209 facilities across 7 countries (Australia, New Zealand, Canada, Japan, Thailand, United Kingdom, United States). EXPOSURES: Facility characteristics (census count, facility age, nurse to patient ratio) and selected facility practices (use of automated PD, use of icodextrin or biocompatible PD solutions, antibiotic prophylaxis strategies, duration of PD training). OUTCOMES: Peritonitis rate (by country, overall and variation across facilities), microbiology patterns. ANALYTICAL APPROACH: Poisson rate estimation, proportional rate models adjusted for selected patient case-mix variables. RESULTS: 2,272 peritonitis episodes were identified in 7,051 patients (crude rate, 0.28 episodes/patient-year). Facility peritonitis rates were variable within each country and exceeded 0.50/patient-year in 10% of facilities. Overall peritonitis rates, in episodes per patient-year, were 0.40 (95% CI, 0.36-0.46) in Thailand, 0.38 (95% CI, 0.32-0.46) in the United Kingdom, 0.35 (95% CI, 0.30-0.40) in Australia/New Zealand, 0.29 (95% CI, 0.26-0.32) in Canada, 0.27 (95% CI, 0.25-0.30) in Japan, and 0.26 (95% CI, 0.24-0.27) in the United States. The microbiology of peritonitis was similar across countries, except in Thailand, where Gram-negative infections and culture-negative peritonitis were more common. Facility size was positively associated with risk for peritonitis in Japan (rate ratio [RR] per 10 patients, 1.07; 95% CI, 1.04-1.09). Lower peritonitis risk was observed in facilities that had higher automated PD use (RR per 10 percentage points greater, 0.95; 95% CI, 0.91-1.00), facilities that used antibiotics at catheter insertion (RR, 0.83; 95% CI, 0.69-0.99), and facilities with PD training duration of 6 or more (vs <6) days (RR, 0.81; 95% CI, 0.68-0.96). Lower peritonitis risk was seen in facilities that used topical exit-site mupirocin or aminoglycoside ointment, but this association did not achieve conventional levels of statistical significance (RR, 0.79; 95% CI, 0.62-1.01). LIMITATIONS: Sampling variation, selection bias (rate estimates), and residual confounding (associations). CONCLUSIONS: Important international differences exist in the risk for peritonitis that may result from varied and potentially modifiable treatment practices. These findings may inform future guidelines in potentially setting lower maximally acceptable peritonitis rates.

Regional variation in the treatment and prevention of peritoneal dialysis-related infections in the Peritoneal Dialysis Outcomes and Practice Patterns Study.

BACKGROUND: Peritoneal dialysis (PD)-related infections lead to significant morbidity. The International Society for Peritoneal Dialysis (ISPD) guidelines for the prevention and treatment of PD-related infections are based on variable evidence. We describe practice patterns across facilities participating in the Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS). METHODS: PDOPPS, a prospective cohort study, enrolled nationally representative samples of PD patients in Australia/New Zealand (ANZ), Canada, Thailand, Japan, the UK and the USA. Data on PD-related infection prevention and treatment practices across facilities were obtained from a survey of medical directors'. RESULTS: A total of 170 centers, caring for >11 000 patients, were included. The proportion of facilities reporting antibiotic administration at the time of PD catheter insertion was lowest in the USA (63%) and highest in Canada and the UK (100%). Exit-site antimicrobial prophylaxis was variably used across countries, with Japan (4%) and Thailand (28%) having the lowest proportions. Exit-site mupirocin was the predominant exit-site prophylactic strategy in ANZ (56%), Canada (50%) and the UK (47%), while exit-site aminoglycosides were more common in the USA (72%). Empiric Gram-positive peritonitis treatment with vancomycin was most common in the UK (88%) and USA (83%) compared with 10-45% elsewhere. Empiric Gram-negative peritonitis treatment with aminoglycoside therapy was highest in ANZ (72%) and the UK (77%) compared with 10-45% elsewhere. CONCLUSIONS: Variation in PD-related infection prevention and treatment strategies exist across countries with limited uptake of ISPD guideline recommendations. Further work will aim to understand the impact these differences have on the wide variation in infection risk between facilities and other clinically relevant PD outcomes.

Con: The role of diet for people with advanced Stage 5 CKD.

Restriction of dietary protein intake has been used in the management of chronic kidney disease (CKD) for many decades, yet remains controversial, with marked variations in its application in clinical practice. There is extensive literature on the subject, with some expert opinion advocating the use of protein restriction based on the balance of the available evidence. The largest randomized trial of low-protein diets is the Modification of Diet in Renal Disease study. Despite multiple secondary analyses, the essential intention-to-treat analysis failed to demonstrate a benefit in the primary outcome of rate of decline of glomerular filtration rate. There are criticisms of many published studies and meta-analyses, including the likelihood of publication bias and unsuitable biochemical endpoints that may be affected by dietary restriction in the absence of effects on kidney function, leading to false positive findings. It is also uncertain whether any benefits observed in these often older studies would be derived in patients undergoing modern standards of CKD management, including blood pressure control and renin-angiotensin blockade. Thus it is unclear whether, even in the strictly controlled environment of a clinical study, low-protein diets significantly slow CKD progression. Important questions exist regarding the applicability of these diets in routine clinical practice. Even in carefully selected study populations with intensive dietetic input, adherence to low-protein diets is poor. It is likely that only a small minority of CKD patients in routine practice could adhere to these diets, and although risks of malnutrition arising from protein restriction are uncertain, they will be greater in less supervised care outside of studies.

Renal Association Clinical Practice Guideline on peritoneal dialysis in adults and children.

These guidelines cover all aspects of the care of patients who are treated with peritoneal dialysis. This includes equipment and resources, preparation for peritoneal dialysis, and adequacy of dialysis (both in terms of removing waste products and fluid), preventing and treating infections. There is also a section on diagnosis and treatment of encapsulating peritoneal sclerosis, a rare but serious complication of peritoneal dialysis where fibrotic (scar) tissue forms around the intestine. The guidelines include recommendations for infants and children, for whom peritoneal dialysis is recommended over haemodialysis.Immediately after the introduction there is a statement of all the recommendations. These recommendations are written in a language that we think should be understandable by many patients, relatives, carers and other interested people. Consequently we have not reworded or restated them in this lay summary. They are graded 1 or 2 depending on the strength of the recommendation by the authors, and A-D depending on the quality of the evidence that the recommendation is based on.

Longitudinal bioimpedance vector plots add little value to fluid management of peritoneal dialysis patients.

Bioimpedance (BI) has the potential to enable better management of fluid balance, which can worsen over time on peritoneal dialysis (PD) due to loss of residual kidney function and progressive muscle wasting. We undertook a prospective, randomized, open-label, blinded end-point controlled trial to determine whether availability of longitudinal BI measures as vector plots helped clinicians maintain stable fluid status over 12 months in 308 peritoneal dialysis patients from the United Kingdom and Shanghai, China. Patients were recruited into 4 groups nested within a single trial design according to country and residual kidney function. Nonanuric subjects from both countries demonstrated stable fluid volumes irrespective of randomization. Hydration worsened in control anuric patients in Shanghai with increased extracellular/total body water (ECW/TBW) ratio (0.04; 95% CI: 0.01, 0.06) and reduced TBW (-1.76 L 95% CI: -2.70, -0.82), but was stable in the BI intervention group whose dialysate glucose prescription was increased. However, multilevel analysis incorporating data from both countries showed worsening ECW/TBW in active and control anuric patients. Clinicians in the United Kingdom reduced target weight in the nonanuric BI intervention group causing a reduction in TBW without beneficial effects on ECW or blood pressure. Thus, routine use of longitudinal BI vector plots to improve clinical management of fluid status is not supported.

Novel Colorimetric and Light Scatter Methods to Identify and Manage Peritoneal Dialysis-Associated Peritonitis at the Point-of-Care.

Introduction: Peritoneal dialysis (PD)-related peritonitis (PDRP) is a common cause of transfer to hemodialysis, patient morbidity, and is a risk factor for mortality. Associated patient anxiety can deter selection of PD for renal replacement therapy. Diagnosis relies on hospital laboratory tests; however, this might be achieved earlier if such information was available at the point-of-care (POC), thereby significantly improving outcomes. The presence of culturable microbes and the concentration of leukocytes in effluent both aid peritonitis diagnosis, as specified in the International Society for Peritoneal Dialysis (ISPD) diagnostic guidelines. Here, we report the development of 2 new methods providing such information in simple POC tests. Methods: One approach uses a tetrazolium-based chemical reporting system, primarily focused on detecting bacterial contamination and associated vancomycin-sensitivity. The second approach uses a novel forward light-scatter device (QuickCheck) to provide an instant quantitative cell count directly from PD patient effluent. Results: The tetrazolium approach detected and correctly distinguished laboratory isolates, taking 10 hours to provide non-quantitative results. We compared the technical performance of the light scatter leukocyte counting approach with spectrophotometry, hemocytometer counting and flow cytometry (Sysmex) using patient effluent samples. QuickCheck had high accuracy (94%) and was the most precise (coefficient of variation <4%), showing minimal bias, overall performing similarly to flow cytometry. Conclusion: These complementary new approaches provide a simple means to obtain information to assist diagnosis at the POC. The first provides antibiotic sensitivity following 10 hours incubation, whereas the second optical approach (QuickCheck), provides instant accurate total leukocyte count.

Body composition analysis techniques in the aged adult: indications and limitations.

PURPOSE OF REVIEW: Body composition analysis allows division of the body into different compartments on the basis of differing physical properties. A variety of techniques are available for measuring body composition. This review describes the changes that occur with increasing age, their significance and also the limitations of available body composition analysis techniques when applied to the elderly. RECENT FINDINGS: Studies have shown the development of changes in body composition with ageing that have important consequences for health. Alterations in body fat content and particularly body fat distribution are associated with adverse metabolic effects and increased cardiovascular risk. Reduced skeletal muscle mass and strength (sarcopenia) are common in the elderly with important effects on function and outcome. A range of techniques are available for measuring body composition. However, changes in body composition with ageing, particularly altered composition of the constituents of fat-free mass, and changes in fat distribution, may lead to measurement errors with standard body composition assessment methodology. SUMMARY: Measurement of body composition provides information of importance to health and function. Techniques used for assessment should be those unaffected by age-related changes in body composition, or those that have been adapted or validated in this age group. Particular roles of these techniques in the elderly include screening or surveillance of those at risk of malnutrition, and monitoring a range of chronic illnesses that are prevalent in older individuals.

Quality of life with conservative care compared with assisted peritoneal dialysis and haemodialysis.

BACKGROUND: There is little information about quality of life (QoL) for patients with end-stage kidney disease (ESKD) choosing conservative kidney management (CKM). The Frail and Elderly Patients on Dialysis (FEPOD) study demonstrated that frailty was associated with poorer QoL outcomes with little difference between dialysis modalities [assisted peritoneal dialysis (aPD) or haemodialysis (HD)]. We therefore extended the FEPOD study to include CKM patients with estimated glomerular filtration rate ≤10 mL/min/1.73 m2 (i.e. individuals with ESKD otherwise likely to be managed with dialysis). METHODS: CKM patients were propensity matched to HD and aPD patients by age, gender, ethnicity, diabetes status and index of deprivation. QoL outcomes measured were Short Form-12 (SF12), Hospital Anxiety and Depression Scale depression score, symptom score, Illness Intrusiveness Rating Scale (IIRS) and Renal Treatment Satisfaction Questionnaire. Frailty was assessed using the Clinical Frailty Scale. Generalized linear modelling was used to assess the impact of treatment modality on QoL outcomes, adjusting for baseline characteristics. RESULTS: In total, 84 (28 CKM, 28 HD and 28 PD) patients were included. Median age for the cohort was 82 (79-88) years. Compared with CKM, aPD was associated with higher SF12 physical component score (PCS) [Exp B (95% confidence interval) = 1.20 (1.00-1.45), P < 0.05] and lower symptom score [Exp B = 0.62 (0.43-0.90), P = 0.01]; depression score was lower in HD compared with CKM [Exp B = 0.70 (0.52-0.92), P = 0.01]. Worsening frailty was associated with higher depression scores [Exp B = 2.59 (1.45-4.62), P < 0.01], IIRS [Exp B = 1.20 (1.12-1.28), P < 0.01] and lower SF12 PCS [Exp B = 0.87 (0.83-0.93), P < 0.01]. CONCLUSION: Treatment by dialysis, both with aPD and HD, improved some QoL measures. Overall, aPD was equal to or slightly better than the other modalities in this elderly population. However, as in the primary FEPOD study, frailty was associated with worse QoL measures irrespective of CKD modality. These findings highlight the need for an individualized approach to the management of ESKD in older people.

Longitudinal Trends in Quality of Life and Physical Function in Frail Older Dialysis Patients: A Comparison of Assisted Peritoneal Dialysis and In-Center Hemodialysis.

BACKGROUND: In-center hemodialysis (HD) has been the standard treatment for older dialysis patients, but reports suggest an associated decline in physical and cognitive function. Cross-sectional data suggest that assisted peritoneal dialysis (aPD), an alternative treatment, is associated with quality of life (QoL) outcomes that are comparable to in-center HD. We compared longitudinal changes in QoL between modalities. METHODS: We enrolled 106 aPD patients, matched with 100 HD patients from 20 renal centers in England and Northern Ireland. Patients were assessed quarterly for 2 years using the Hospital Anxiety and Depression Scale (HADS), SF-12 physical and mental scores, symptom score, Illness Intrusiveness Rating Scale (IIRS), Barthel's score, and the Renal Treatment Satisfaction Questionnaire (RTSQ). Mixed model analysis was used to assess the impact of dialysis modality on these outcomes during follow-up. P values were adjusted for multiple significance testing. RESULTS: Multivariate analysis showed no difference in any of the outcome measures between aPD and HD. Longitudinal trends in outcomes were also not significantly different. Higher age at baseline was associated with lower IIRS and RTSQ scores during follow-up. One-hundred and twenty-five (60.6%) patients dropped out of the study: 59 (28.6%) died, 61 (29.6%) withdrew during follow-up, and 5 (2.5%) were transplanted. CONCLUSIONS: Quality of life outcomes in frail older aPD patients were equivalent to those receiving in-center HD. Assisted PD is thus a valid alternative to HD for older people with end-stage kidney disease (ESKD) wishing to dialyze at home.

Longitudinal relationships between fluid status, inflammation, urine volume and plasma metabolites of icodextrin in patients randomized to glucose or icodextrin for the long exchange.

BACKGROUND: Randomized trials have shown that icodextrin reduces the volume of extra-cellular fluid (ECFv) with variable effects on residual renal function. To explore this fluid shift and its possible mechanisms in more detail, prospectively collected data from one such trial, including measures of inflammation (C-reactive protein, tumour necrosis factor-alpha, albumin and low and high molecular weight hyaluronan) ANP (atrial naturetic peptide), an indirect marker of intra-vascular volume, plasma concentrations of icodextrin metabolites and alpha-amylase activity were analysed. METHODS: 50 patients were randomized to either 2.27% glucose or icodextrin (n = 28) for a long exchange following a month run in. Blood samples were obtained at -1, 0, 3 and 6 months, coincident with measurements of urine volume and fluid status. RESULTS: In both randomized groups, a significant correlation between the fall in ECFv and the decline in urine volume was observed (P = 0.001), although the relative drop in urine volume for patients randomized to icodextrin tended to be less. At baseline, ANP was higher in patients with proportionately more ECFv for a given body water or height. Icodextrin patients had non-significantly higher ANP levels at baseline, whereas by 3 (P = 0.026) and 6 months (P = 0.016) these differed between groups due to divergence. There was a correlation between increasing ANP and reduced ECF at 3 months, r = -0.46, P = 0.007, in patients randomized to icodextrin, but not glucose. There were no relationships between fluid status and any inflammatory markers at any point of the study, with the exception of albumin at baseline, r = -0.39, P = 0.007. Amylase activities at -1 month and baseline were highly correlated, r = 0.89, P < 0.0001. Within patients, concentrations of icodextrin metabolites were highly correlated; the only predictor of between-patient variability on multivariate analysis was body weight. There was no relationship between plasma concentrations of icodextrin metabolites and any of the other clinical parameters, including change in daily ultrafiltration, urine volume, fluid or inflammatory status. CONCLUSIONS: This analysis supports observational data that changes in fluid status are associated with changes in urine volume. Icodextrin was not associated with a greater fall in urine output despite its larger effect on ECFv. Changes in fluid status could not be explained or did not appear to influence systemic inflammation. Nor can they be explained by individual variability in plasma concentrations of icodextrin that are in turn inversely proportional to the volume of distribution.

Methodology of assessment of fluid status and ultrafiltration problems.

Loss of sodium and water excretion with disruption of volume homeostasis is a crucial abnormality of end-stage renal failure. Fluid management is a fundamental function of dialysis therapy, but studies show frequent occult fluid overload, hypertension, and cardiac dysfunction in peritoneal dialysis. A rigorous approach to fluid management in PD can achieve excellent fluid, hypertension, and cardiovascular results in clinical practice. The present article explores the reasons for fluid overload and poor ultrafiltration in peritoneal dialysis patients and discusses optimal assessment and management of these problems.

Body composition analysis techniques in adult and pediatric patients: how reliable are they? How useful are they clinically?

Complex abnormalities of body composition occur in peritoneal dialysis (PD). These abnormalities reflect changes in hydration, nutrition, and body fat, and they are of major clinical significance. Clinical assessment of these body compartments is insensitive and inaccurate. Frequently, simultaneous changes of hydration, wasting, and body fat content can occur, confounding clinical assessment of each component. Body composition can be described by models of varying complexity that use one or more measurement techniques. "Gold standard" methods provide accurate and precise data, but are not practical for routine clinical use. Dual energy X-ray absorptiometry allows for measurement of regional as well as whole-body composition, which can provide further information of clinical relevance. Simpler techniques such as anthropometry and bioelectrical impedance analysis are suited to routine use in clinic or at the bedside, but may be less accurate. Body composition methodology sometimes makes assumptions regarding relationships between components, particularly in regard to hydration, which may be invalid in pathologic states. Uncritical application of these methods to the PD patient may result in erroneous interpretation of results. Understanding the foundations and limitations of body composition techniques allows for optimal application in clinical practice.

Application of bioelectrical impedance to clinical assessment of body composition in peritoneal dialysis.

Patients on peritoneal dialysis (PD) develop complex changes in body composition. These changes reflect hydration, nutrition, and body fat, all important elements reflecting patient well-being and efficacy of therapy that should be assessed and monitored as guides to patient management. They are all notoriously difficult to accurately measure in clinical practice and simultaneous abnormalities may obscure detection, as in the malnourished fluid-overloaded patient where body weight is misleadingly stable. Malnutrition is a serious complication in PD that carries an adverse prognosis. Assessment of hydration in PD is important in determining "dry weight" to allow adjustment of dialysis prescription to optimize fluid balance. A number of techniques have been investigated to measure body composition in clinical practice. Of these, bioelectrical impedance analysis (BIA) has attracted most interest and seems to be of greatest promise. Cases illustrating different aspects of the use of BIA in PD patients are described, and the background, possible uses, and limitations of BIA in PD patients are discussed. To be of clinical value, BIA must be used to distinguish between extracellular water (which reflects hydration) and body cell mass, or intracellular water (which declines in wasting and malnutrition). The high precision of BIA is ideally suited to detecting changes in body composition and its main role may be in longitudinal monitoring. However, inaccuracy of absolute measurements and variability of normal values in the general population make precise diagnosis of the degree of normality of body composition in an individual subject a more difficult task for body composition analysis.