Outcomes of peritoneal dialysis patients and switching to hemodialysis: a competing risks analysis

Antibiotic availability for outpatient treatment of acute peritonitis in chronic peritoneal dialysis patients: A case series

BACKGROUND

Peritoneal dialysis (PD) is a commonly used form of renal replacement therapy for patients that have reached end-stage renal disease. Acute bacterial peritonitis (ABP) in chronic PD patients results in pain, increased costs, injury to the peritoneal membrane, and PD modality failure. Optimal antibiotic treatment of acute bacterial peritonitis (ABP) in chronic PD patients should be intraperitoneal, outpatient-based, appropriate, prompt, and uninterrupted. We investigated the frequency of and predisposition to suboptimal antibiotic courses for ABP in our chronic PD patients.

METHODS

Twenty-four charts of patients with ABP were reviewed, to test the null hypothesis that all ABP patients received antibiotics optimally.

RESULTS

After 12 patient exclusions (hospitalization), 9 suboptimal antibiotic events were detected in 6 of the remaining 12 patients, disproving the null hypothesis (p < 0.02). Most suboptimal antibiotics courses (7 of 9) resulted from delays and/or gaps in therapy or antibiotics prescribed outside of community standard. Suboptimal antibiotic events occurred on nights and weekends rather than during the workweek (p < 0.02) and in the emergency room rather than the PD clinic (p < 0.02).

CONCLUSIONS

Suboptimal ABP antibiotic therapy occurs commonly and is influenced by time and location of presentation and lack of knowledge by patients and physicians. Prevention of suboptimal antibiotic courses in the treatment of ABP in chronic PD patients includes education of patients and providers and allowing emergency rooms and PD clinics to dispense antibiotics for home use.

Impact of peritoneal dialysis modality on patient and PD survival: A systematic review

We conducted a systematic review and meta-analysis to determine the effect of the peritoneal dialysis (PD) modality, automated peritoneal dialysis (APD) or continuous ambulatory peritoneal dialysis (CAPD), on all-cause mortality (ACM) and PD failure. Studies were identified in PubMed, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), China National Knowledge Infrastructure, Weipu and Wanfang databases from database inception until April 1, 2021. The inclusion and exclusion criteria were based on the Population, Intervention, Comparison, Outcome, and Study (PICOS) design. Adjusted hazard ratios (HRs) with 95% confidence intervals (CI) were used to pool outcome estimates. Seventeen studies (more than 230,000 patients) were included. Our meta-analysis showed that compared with CAPD, APD demonstrated a significantly lower ACM risk (HR 0.87 [95% CI 0.77–0.99], p = 0.04), especially in studies involving an as-treated analysis (HR 0.75 [95% CI, 0.63–0.90], p = 0.00), published in Asia (HR 0.76 [95% CI, 0.67–0.86], p < 0.001) or Europe (HR 0.81 [95% CI, 0.74–0.89], p < 0.00), or published after 2012 (HR 0.82 [95% CI, 0.68–0.99], p = 0.04). However, APD was as effective as CAPD for PD survival (HR, 0.87 [95% CI, 0.75 to 1.00], p = 0.05 or HR, 0.90 [95% CI, 0.60 to 1.35], p = 0.61). Our results demonstrate a significant survival benefit for APD and provide evidence for increasing the global use of APD, especially in developing nations, where APD use has been hampered by a lack of reimbursement for care.

Transitions in an integrated model of renal replacement therapy in a regional health system

INTRODUCTION AND OBJECTIVES

The choice of renal replacement therapy (RRT) is an important decision that determines the quality of life and survival. Most patients change from one RRT modality to another to adapt RRT to clinical and psychosocial needs. This has been called «integrated model of RRT» that implies new questions about the best sequence of techniques.

MATERIAL AND METHODS

The study describes the impact of transitions between RRT modalities on survival using the Madrid Registry of Renal Patients (2008-2018). This study used the proportional hazards models and competitive risk models to perform an intention-to-treat (ITT), according to their 1st RRT modality and as-treated (AT) analysis, that consider also their 1st transition.

RESULTS

A total of 8971 patients started RRT during this period in Madrid (6.6 Million population): 7207 (80.3%) on hemodialysis (HD), 1401 (15.6%) on peritoneal dialysis (PD) and 363 (4.2%) received a pre-emptive kidney transplantation (KT). Incident HD-patients were older (HD group 65.3 years (SD 15.3) vs PD group 58.1 years (SD 14.8) vs KTX group 52 years (SD 17.2); p < 0.001) and had more comorbidities. They presented higher mortality (HD group 40.9% vs PD group 22.8% vs KTX group 8.3%, p < 0.001) and less access to a transplant (HD group 30.4% vs PD group 51.6%; p < 0.001). Transitions between dialysis techniques define different groups of patients with different clinical outcomes. Those who change from HD to PD do it earlier (HD → PD: 0.7 years (SD 1.1) vs PD → HD: 1.5 years (SD 1.4) p < 0.001), are younger (HD → PD: 53.5 years (SD 16.7) vs PD → HD: 61.6 years (SD 14.6); p < 0.001), presented less mortality (HD → PD: 24.5% vs PD → HD: 32.0%; p < 0.001) and higher access to a transplant (HD → PD: 49.4% vs PD → HD: 31.7%; p < 0.001). Survival analysis by competitive risks is essential for integrated RRT models, especially in groups such as PD patients, where 51.6% of the patients were considered as lost follow-up (received a KTX after during the first 2.5 years on PD). In this analysis, survival of patients who change from one technique to another, is more similar to the destination modality than the origin one.

CONCLUSION

Our data suggest that transitions between RRT-techniques describes different patients, who associate different risks, and could be analyzed in an integrated manner to define improvement actions. This approach should be incorporated into the analysis and reports of renal registries.

Hyperspectral evaluation of vasculature in induced peritonitis mouse models

Imaging of blood vessel structure in combination with functional information about blood oxygenation can be important in characterizing many different health conditions in which the growth of new vessels contributes to the overall condition. In this paper, we present a method for extracting comprehensive maps of the vasculature from hyperspectral images that include tissue and vascular oxygenation. We also show results from a preclinical study of peritonitis in mice. First, we analyze hyperspectral images using Beer-Lambert exponential attenuation law to obtain maps of hemoglobin species throughout the sample. We then use an automatic segmentation algorithm to extract blood vessels from the hemoglobin map and combine them into a vascular structure-oxygenation map. We apply this methodology to a series of hyperspectral images of the abdominal wall of mice with and without induced peritonitis. Peritonitis is an inflammation of peritoneum that leads, if untreated, to complications such as peritoneal sclerosis and even death. Characteristic inflammatory response can also be accompanied by changes in vasculature, such as neoangiogenesis. We demonstrate a potential application of the proposed segmentation and processing method by introducing an abnormal tissue fraction metric that quantifies the amount of tissue that deviates from the average values of healthy controls. It is shown that the proposed metric successfully discriminates between healthy control subjects and model subjects with induced peritonitis and has a high statistical significance.

The availability of support and peritoneal dialysis survival: A cohort study

BACKGROUND

Providing support is important to maintain a patient on peritoneal dialysis (PD), though its impact on outcomes has not been investigated thoroughly. We examined the association between having support and risk of a transfer to hemodialysis.

METHODS

In this retrospective observational cohort study, we used data captured in the Dialysis Measurement Analysis and Reporting system about patients who started PD in Alberta, Canada, between 1 January 2013 and 30 September 2018. Support was defined as the availability of a support person in the home who was able, willing and available to provide support for PD in the patient's residence. The outcome of interest was a transfer to hemodialysis for at least 90 days. We estimated the cumulative incidence of a transfer over time accounting for competing risks and hazard ratios to summarise the association between support and a transfer. We split follow-up time as hazard ratios varied over time.

RESULTS

Six hundred and eighty-three incident PD patients, median age 58 years (IQR: 47-68) and 35% female, were followed for a median of 15 months. The cumulative incidence of a transfer to hemodialysis at 24 months was 26%. Having support was associated with a reduced risk of a transfer between 3 and 12 months after the start of dialysis (HR_3-12mo: 0.44; 95% CI: 0.25-0.78), but not earlier (hazard ratio (HR)_<3mo: 0.96; 95% confidence interval (CI): 0.55-1.69) or later (HR_>12mo: 1.19; 95% CI: 0.65-2.17).

CONCLUSIONS

A transfer to hemodialysis is common. Having a support person at home is associated with a short-term protective effect after the initiation of PD.

Increased risk of modality failure with higher serum uric acid level in continuous ambulatory peritoneal dialysis patients: a prospective cohort study

BACKGROUND

Peritoneal dialysis (PD) is one of the most important kidney replacement therapies for patients with end-stage kidney disease (ESKD). PD technique failure can lead to an escalated cost and increased infectious and cardiovascular risk, up and including to death. The accumulation of uric acid (UA) was associated with adverse outcomes in ESKD patients. However, the relationship between serum UA and technique failure is little explored.

METHODS

Here, a total of 266 continuous ambulatory peritoneal dialysis (CAPD) patients (age, 41.8 ± 12.6 years; 125 males) were enrolled and followed up for 31.7 months. Serum UA levels were examined at baseline and each visit. Subjects were divided into three groups according to their baseline serum UA concentrations. Multivariable Cox regression models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) of PD technique failure.

RESULTS

The level of serum UA increased gradually as time prolonged. During the follow-up period, 77 (28.9%) patients occurred PD technique failure, of which 56 (21.1%) transferred to hemodialysis (HD) and 21 (7.9%) died. Compared to the lowest UA tertile, after adjusting for potential confounders, HRs of technique failure in tertile 2 and tertile 3 were 1.82 (95% CI: 0.95-3.49) and 2.03 (95% CI: 1.05-3.92), respectively, and p for trend was 0.043. Adjusted HRs of all-cause technique failure, transferring to HD and mortality with each 1 mg/dL increase in serum UA were 1.20 (95% CI: 1.03-1.40, p = 0.019), 1.22 (95% CI: 1.01-1.48, p = 0.039), and 1.25 (95% CI: 0.94-1.67, p = 0.128), respectively.

CONCLUSION

Higher serum UA level predicted higher risk of technique failure in CAPD patients.

Regression of Left Ventricular Hypertrophy in Patients Combined with Peritoneal Dialysis and Hemodialysis

METHODS

This retrospective study enrolled 58 patients at The Second Affiliated Hospital of Soochow University who switched from PD to PHD. Clinical data and echocardiographic examination results were collected. Data from the two groups with a normal distribution were compared with the paired t-test. A pvalue <0.05 (two-tailed) was considered statistically significant.

RESULTS

A total of 58 subjects were enrolled, including 46 males and 12 females, with a median age of 50.2 ± 11.1 (47-68) years. The mean duration of peritoneal dialysis was 67.2 ± 33.6 months. Before and after PHD, the ultrafiltration volume (p = 0.021) and hemoglobin (p = 0.001) were increased, while SBP (p = 0.002), DBP (p = 0.002), phosphorus (p < 0.001), and ESA dosage (p < 0.001) were decreased. Before and after combined dialysis (PHD), the incidence of LVH was 76.4% and 61.8%, respectively (p = 0.013), and LVMI decreased from 173.8 ± 86.2 g/m² to 160.6 ± 78.5 g/m² (p < 0.001).

CONCLUSION

Compared with PD alone, the combination of PD and HD resulted in regression of LVH and reduced LVMI.

Transitions in an integrated model of renal replacement therapy in a regional health system

INTRODUCTION AND OBJECTIVES

The choice of renal replacement therapy (RRT) is an important decision that determines the quality of life and survival. Most patients change from one RRT modality to another to adapt RRT to clinical and psychosocial needs. This has been called «integrated model of RRT» that implies new questions about the best sequence of techniques.

MATERIAL AND METHODS

The study describes the impact of transitions between RRT modalities on survival using the Madrid Registry of Renal Patients (2008-2018). This study used the proportional hazards models and competitive risk models to perform an intention-to-treat (ITT), according to their 1st RRT modality and as-treated (AT) analysis, that consider also their 1st transition.

RESULTS

A total of 8971 patients started RRT during this period in Madrid (6.6 Million population): 7207 (80.3%) on hemodialysis (HD), 1401 (15.6%) on peritoneal dialysis (PD) and 363 (4.2%) received a pre-emptive kidney transplantation (KTX). Incident HD-patients were older (HD group 65.3 years (SD 15.3) vs PD group 58.1 years (SD 14.8) vs KTX group 52 years (SD 17.2); p<0.001) and had more comorbidities. They presented higher mortality (HD group 40.9% vs PD group 22.8% vs 8.3% KTX group, p<0.001) and less access to a transplant (HD group 30.4% vs DP group 51.6%; p<0.001). Transitions between dialysis techniques define different groups of patients with different clinical outcomes. Those who change from HD to PD do it earlier (HD→PD: 0.7 years (SD 1.1) vs PD→HD: 1.5 years (SD 1.4) p<0.001), are younger (HD→PD: 53.5 years (SD 16.7) vs PD→HD: 61.6 years (SD 14.6); p<0.001), presented less mortality (HD→PD: 24.5% vs PD→HD: 32.0%; p<0.001) and higher access to a transplant (HD→PD: 49.4% vs PD→HD: 31.7%; p<0.001). Survival analysis by competitive risks is essential for integrated RRT models, especially in groups such as PD patients, where 51.6% of the patients were considered as lost follow-up (received a KTX after during the first 2.5 years on PD). In this analysis, survival of patients who change from one technique to another, is more similar to the destination modality than the origin one.

CONCLUSION

Our data suggest that transitions between RRT-techniques describes different patients, who associate different risks, and could be analyzed in an integrated manner to define improvement actions. This approach should be incorporated into the analysis and reports of renal registries.

Mortality After Home Hemodialysis Treatment Failure and Return to In-Center Hemodialysis

RATIONALE OBJECTIVE

Patients on home hemodialysis (HHD) may eventually return to in-center hemodialysis (ICHD) for clinical, technical or psycho-social reasons. We studied the mortality of patients returning to ICHD after HHD comparing it to the mortality experience among patients receiving HHD and patients receiving ICHD without prior treatment with HHD.

STUDY DESIGN

Retrospective cohort study.

SETTING PARTICIPANTS

All patients represented in the Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry who commenced HD during 2005-2015 and were treated for >90 days.

EXPOSURES

ICHD and/or HHD, and clinical characteristics at study entry.

OUTCOMES

Mortality and cause of death.

ANALYTICAL APPROACH

A time-varying multivariate Cox proportional hazards analysis with shared frailty was implemented to explore the association between patient treatment states and mortality. Patients were censored at the time of transplantation and change in treatment modality to peritoneal dialysis.

RESULTS

A total of 19,306 patients initiated HD and were treated for >90 days. The mean age of patients was 60.8y (SD=15.4y), 62% were male and 49% had diabetes. After HHD treatment failure, adjusted mortality was increased compared to continued HHD at 0-30 days (HR 3.93, 95% CI 2.09-7.40 p<0.001), 30-90 days (HR 3.34, 95% CI 1.98-5.62, p<0.001) and >90 days (HR 2.29, CI 1.84-2.85, p<0.001).

LIMITATIONS

Covariates recorded at dialysis initiation. Residual confounding underlying successful initiation of HHD treatment.Observational data lacking detail on cause of HHD treatment failure.

CONCLUSIONS

HHD treatment failure is associated with a significant increase in mortality compared to continued HHD. This risk was present in both the early (first 30 days and 30-90 days) and late (>90 days) periods after HHD treatment failure. Further investigation into the specific causes of treatment failure and death may highlight specific high-risk patients.

Four steps to standardize reporting of peritoneal dialysis technique failure: A proposed approach

BACKGROUND

Technique failure is an important outcome measure in research and quality improvement in peritoneal dialysis (PD) programs, but there is a lack of consistency in how it is reported.

METHODS

We used data collected about incident dialysis patients from 10 Canadian dialysis programs between 1 January 2004 and 31 December 2018. We identified four main steps that are required when calculating the risk of technique failure. We changed one variable at a time, and then all steps, simultaneously, to determine the impact on the observed risk of technique failure at 24 months.

RESULTS

A total of 1448 patients received PD. Selecting different cohorts of PD patients changed the observed risk of technique failure at 24 months by 2%. More than one-third of patients who switched to hemodialysis returned to PD-90% returned within 180 days. The use of different time windows of observation for a return to PD resulted in risks of technique failure that differed by 16%. The way in which exit events were handled during the time window impacted the risk of technique failure by 4% and choice of statistical method changed results by 4%. Overall, the observed risk of technique failure at 24 months differed by 20%, simply by applying different approaches to the same data set.

CONCLUSIONS

The approach to reporting technique failure has an important impact on the observed results. We present a robust and transparent methodology to track technique failure over time and to compare performance between programs.

Changes in mortality hazard of the Korean long-term dialysis population: The dependencies of time and modality switch

BACKGROUND

Many studies have compared patient survival outcome between hemodialysis (HD) and peritoneal dialysis (PD); however, time-varying risks of dialysis modality have been rarely investigated. This study aimed to investigate dialysis modality switch and its association with the survival outcome in the Korean population.

METHODS

Data from the Korean Society of Nephrology were used. A total of 21,840 incident dialysis patients who started dialysis in or after 2000 were analyzed. For the survival analysis, both proportional and non-proportional hazard assumptions were applied. For the modality switch, time-varying covariate Cox regression was applied.

RESULTS

During the median follow-up of 8 years, PD group showed increased adjusted hazard ratio (HR) of 1.248 (95% CI 1.071-1.454, p = 0.004) for mortality. Interaction of PD status with female sex was significant with an HR of 1.080 (95% CI 1.000-1.165, p = 0.050). Dialysis modality switch was associated with increased HR of 1.094 (95% CI 1.015-1.180, p = 0.019), albeit switch from PD to HD did not show significant HR until 6 years. Interestingly, time-varying risk analysis showed a decreased HR of PD after 10 years in the non-switcher group, which was consistent in patients with high traditional risk factors (with diabetes, elderly).

CONCLUSIONS

PD was associated with increased HR of mortality in the first 8 years, then it was associated with decreased HR of mortality after 10 years. Dialysis modality switch was associated with increased mortality risk, but switch from PD to HD within 6 years did not show significant hazard of mortality.

Optimization of Dialysis Modality Transitions for Improved Patient Care

Purpose of review:

Initial and subsequent modality decisions are important, impacting both clinical outcomes and quality of life. Transition from chronic kidney disease to dialysis and between dialysis modalities are periods were patients may be especially vulnerable. Reviewing our current knowledge surrounding these critical periods and identifying areas for future research may allow us to develop dialysis strategies beneficial to patients.

Sources of information:

We searched the electronic database PubMed and queried Google Scholar for English peer-reviewed articles using appropriate keywords (non-exhaustive list): dialysis transitions, peritoneal dialysis, home hemodialysis, integrated care pathway, and health-related quality of life. Primary sources were accessed whenever possible.

Methods:

In this narrative review, we aim to expose the controversies surrounding home-dialysis first strategies and examine the evidence underpinning home-dialysis first strategies as well as home-to-home and home-to-in-center transitions.

Key findings:

Diverse factors must be taken into consideration when choosing initial and subsequent dialysis modalities. Given the limitations of available data (and lack of convincing benefit or detriment of one modality over the other), patient-centered considerations may prime over suspected mortality benefits of one modality or another.

Limitations:

Available data stem almost exclusively from retrospective and observational studies, often using large national and international databases, susceptible to bias. Furthermore, this is a narrative review which takes into account the views and opinions of the authors, especially as it pertains to optimal dialysis pathways.

Implications:

Emphasis must be placed on individual patient goals and preferences during modality selection while planning ahead to achieve timely and appropriate transitions limiting discomfort and anxiety for patients. Further research is required to ascertain specific interventions which may be beneficial to patients.

Transition Between Different Renal Replacement Modalities: Gaps in Knowledge and Care-The Integrated Research Initiative

Patients with end-stage kidney disease (ESKD) have different options to replace the function of their failing kidneys. The "integrated care" model considers treatment pathways rather than individual renal replacement therapy (RRT) techniques. In such a paradigm, the optimal strategy to plan and enact transitions between the different modalities is very relevant, but so far, only limited data on transitions have been published. Perspectives of patients, caregivers, and health professionals on the process of transitioning are even less well documented. Available literature suggests that poor coordination causes significant morbidity and mortality.This review briefly provides the background, development, and scope of the INTErnational Group Research Assessing Transition Effects in Dialysis (INTEGRATED) initiative. We summarize the literature on the transition between different RRT modalities. Further, we present an international research plan to quantify the epidemiology and to assess the qualitative aspects of transition between different modalities.

Preventing Peritoneal Dialysis-Associated Fibrosis by Therapeutic Blunting of Peritoneal Toll-Like Receptor Activity

Peritoneal dialysis (PD) is an essential daily life-saving treatment for end-stage renal failure. PD therapy is limited by peritoneal inflammation, which leads to peritoneal membrane failure as a result of progressive fibrosis. Peritoneal infections, with the concomitant acute inflammatory response and membrane fibrosis development, worsen PD patient outcomes. Patients who remain infection-free, however, also show evidence of inflammation-induced membrane damage and fibrosis, leading to PD cessation. In this case, uraemia, prolonged exposure to bio-incompatible PD solutions and surgical catheter insertion have been reported to induce sterile peritoneal inflammation and fibrosis as a result of cellular stress or tissue injury. Attempts to reduce inflammation (either infection-induced or sterile) and, thus, minimize fibrosis development in PD have been hampered because the immunological mechanisms underlying this PD-associated pathology remain to be fully defined. Toll-like receptors (TLRs) are central to mediating inflammatory responses by recognizing a wide variety of microorganisms and endogenous components released following cellular stress or generated as a consequence of extracellular matrix degradation during tissue injury. Given the close link between inflammation and fibrosis, recent investigations have evaluated the role that TLRs play in infection-induced and sterile peritoneal fibrosis development during PD. Here, we review the findings and discuss the potential of reducing peritoneal TLR activity by using a TLR inhibitor, soluble TLR2, as a therapeutic strategy to prevent PD-associated peritoneal fibrosis.

Planning Vascular Access in Peritoneal Dialysis-Defining High-Risk Patients

BACKGROUND

Peritoneal dialysis (PD) is an effective renal replacement technique. However, every year a considerable number of patients are transferred to hemodialysis (HD). Our aim was to identify those at risk, in order to place an arteriovenous fistula (AVF).

METHODS

Case-control study enrolling all prevalent patients in 2014 and 2015 in our clinic. Groups: 72 case patients who were transferred definitively to HD, 111 control patients (remaining on PD, transplanted, recovered renal function, or deceased).

RESULTS

A total of 183 patients were eligible, with a mean age of 55.2 ± 14.8 years, 56.3% male, 31.1% diabetic, and 49.7% on continuous ambulatory PD. The mean follow-up time was 42.1 ± 25.6 months. Eighty-five patients had an AVF. The groups differed in diabetic nephropathy etiology, and in some PD-related characteristics (Kt/V, creatinine clearance, residual renal function, mean ultrafiltration, natriuretic peptide, peritonitis, hospitalizations, and hypervolemia). In multivariate analysis, Kt/V < 1.7 (odds ratio [OR] 3.00, 95% confidence interval [CI]: 1.20 - 7.50], albumin < 35 g/L (OR 4.03, 95% CI: 1.26 - 12.92), number of hospitalizations 1 to 3 (OR 2.74, 95% CI: 1.15 - 6.53) and 4 or more (OR 10.48, 95% CI: 3.62 - 30.36), and 2 or more peritonitis episodes (OR 2.50, 95% CI: 1.03 - 6.07) were predictors of PD transfer to HD. In those patients who were transferred to HD, 34 initiated HD by AVF, 2 needed a catheter due to a non-functioning AVF, and 36 did not have an AVF needing catheter placement.

CONCLUSIONS

Low Kt/V, low albumin, higher number of hospitalizations, and peritonitis were factors associated with PD transfer to HD, probably indicative of a high-risk PD population where arteriovenous access should be weighed.

Impact of Obesity on Modality Longevity, Residual Kidney Function, Peritonitis, and Survival Among Incident Peritoneal Dialysis Patients

BACKGROUND

The prevalence of severe obesity, often considered a contraindication to peritoneal dialysis (PD), has increased over time. However, mortality has decreased more rapidly in the PD population than the hemodialysis (HD) population in the United States. The association between obesity and clinical outcomes among patients with end-stage kidney disease remains unclear in the current era.

STUDY DESIGN

Historical cohort study.

SETTING & PARTICIPANTS

15,573 incident PD patients from a large US dialysis organization (2007-2011).

PREDICTOR

Body mass index (BMI).

OUTCOMES

Modality longevity, residual renal creatinine clearance, peritonitis, and survival.

RESULTS

Higher BMI was significantly associated with shorter time to transfer to HD therapy (P for trend < 0.001), longer time to kidney transplantation (P for trend < 0.001), and, with borderline significance, more frequent peritonitis-related hospitalization (P for trend = 0.05). Compared with lean patients, obese patients had faster declines in residual kidney function (P for trend < 0.001) and consistently achieved lower total Kt/V over time (P for trend < 0.001) despite greater increases in dialysis Kt/V (P for trend < 0.001). There was a U-shaped association between BMI and mortality, with the greatest survival associated with the BMI range of 30 to < 35kg/m2 in the case-mix adjusted model. Compared with matched HD patients, PD patients had lower mortality in the BMI categories of < 25 and 25 to < 35kg/m2 and had equivalent survival in the BMI category ≥ 35kg/m2 (P for interaction = 0.001 [vs < 25 kg/m2]). This attenuation in survival difference among patients with severe obesity was observed only in patients with diabetes, but not those without diabetes.

LIMITATIONS

Inability to evaluate causal associations. Potential indication bias.

CONCLUSIONS

Whereas obese PD patients had higher risk for complications than nonobese PD patients, their survival was no worse than matched HD patients.

Association between causes of peritoneal dialysis technique failure and all-cause mortality

Technique failure is a frequent complication of peritoneal dialysis (PD), but the association between causes of death-censored technique failure and mortality remains unclear. Using Australian and New Zealand Dialysis and Transplant (ANZDATA) registry data, we examined the associations between technique failure causes and mortality in all incident PD patients who experienced technique failure between 1989-2014. Of 4663 patients, 2415 experienced technique failure attributed to infection, 883 to inadequate dialysis, 836 to mechanical failure and 529 to social reasons. Compared to infection, the adjusted hazard ratios (HR) for all-cause mortality in the first 2 years were 0.83 (95%CI 0.70-0.98) for inadequate dialysis, 0.78 (95%CI 0.66-0.93) for mechanical failure and 1.46 (95%CI 1.24-1.72) for social reasons. The estimates from the competing risk models were similar. There was an interaction between age and causes of technique failure (pinteraction < 0.001), such that the greatest premature mortality was observed in patients aged >60 years post social-related technique failure. There was no association between causes of technique failure and mortality beyond 2 years. In conclusion, infection and social-related technique failure are associated with premature mortality within 2 years post technique failure. Future studies examining the associations may help to improve outcomes in these patients.

Functional and Transcriptomic Characterization of Peritoneal Immune-Modulation by Addition of Alanyl-Glutamine to Dialysis Fluid

Peritonitis remains a major cause of morbidity and mortality during chronic peritoneal dialysis (PD). Glucose-based PD fluids reduce immunological defenses in the peritoneal cavity. Low concentrations of peritoneal extracellular glutamine during PD may contribute to this immune deficit. For these reasons we have developed a clinical assay to measure the function of the immune-competent cells in PD effluent from PD patients. We then applied this assay to test the impact on peritoneal immune-competence of PD fluid supplementation with alanyl-glutamine (AlaGln) in 6 patients in an open-label, randomized, crossover pilot trial (EudraCT 2012-004004-36), and related the functional results to transcriptome changes in PD effluent cells. Ex-vivo stimulation of PD effluent peritoneal cells increased release of interleukin (IL) 6 and tumor necrosis factor (TNF) α. Both IL-6 and TNF-α were lower at 1 h than at 4 h of the peritoneal equilibration test but the reductions in cytokine release were attenuated in AlaGln-supplemented samples. AlaGln-supplemented samples exhibited priming of IL-6-related pathways and downregulation of TNF-α upstream elements. Results from measurement of cytokine release and transcriptome analysis in this pilot clinical study support the conclusion that suppression of PD effluent cell immune function in human subjects by standard PD fluid is attenuated by AlaGln supplementation.

Dialysis access: issues related to conversion from peritoneal dialysis to hemodialysis and vice versa

Hemodialysis (HD) and peritoneal dialysis (PD) represent two complementary modalities of renal replacement therapy (RRT) for end-stage renal disease patients. Conversion between the two modalities is frequent and more likely to happen from PD to HD. Every year, 10% of PD patients convert to HD, suggesting the need for recommendations on how to proceed with the creation of a vascular access in these patients. Criteria for selecting patients who would likely fail PD, and therefore take advantage of a backup access, are undefined. Creating backup fistulas at the time of PD treatment start to allow emergency access for HD has proved to be inefficient, but it may be considered in patients with progressive difficulty in achieving adequate depuration and/or peritoneal ultrafiltration. A big challenge is represented by patients switching from PD to HD for unexpected infectious complications. Those patients need to start HD with a central venous catheter (CVC), but an alternative approach might be using an early cannulation graft, provided that infection has been cleared by the circulation. An early cannulation graft might also be used to considerably shorten the time spent using a CVC. In patients who need a conversion from HD to PD, urgent-start PD is now an accepted and well-established approach.

Innovations in Treatment Delivery, Risk of Peritonitis, and Patient Retention on Peritoneal Dialysis

Early innovations in the delivery of peritoneal dialysis (PD) markedly improved its acceptability and lowered peritonitis rates. The standard osmotic agent was, and continues to be dextrose, an agent that is not ideal as it is readily absorbed. The development of icodextrin-containing dialysis fluid has allowed a long dwell time to provide more effective ultrafiltration. The development of a smaller, more easily used automated cycler, led to an increase in the proportion of patients on the cycler as opposed to CAPD. Recently, new cyclers with better teaching tools and ease of use and communication with the training team have come on the market; data on outcomes using these cyclers are not yet available. Peritonitis continues to be a serious complication of PD although improvements in connectology and research on Staphylococcus aureus carriage have decreased peritonitis risk. Peritonitis rates continue to vary tremendously from one program to another, which may be in part due to failure to follow best demonstrated practices in training, care of the l catheter exit site, and prevention of peritonitis. Peritonitis rates should be expressed as episodes per year at risk and as organism-specific rates to allow comparisons from one program to another, from one period to another and from a program to the published literature. The term technique failure is misused in PD. Patients leave PD for a host of reasons including transplantation. Transfer from PD to hemodialysis can be planned and have an excellent outcome or can be delayed or done emergently and have a less optimal outcome. The life plan of the patient with ESRD needs to be not only considered but also periodically revised as circumstances and patient wishes change.

Hospitalization Rates for Patients on Assisted Peritoneal Dialysis Compared with In-Center Hemodialysis

BACKGROUND AND OBJECTIVES

Assisted peritoneal dialysis is a treatment option for individuals with barriers to self-care who wish to receive home dialysis, but previous research suggests that this treatment modality is associated with a higher rate of hospitalization. The objective of our study was to determine whether assisted peritoneal dialysis has a different rate of hospital days compared to in-center hemodialysis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We conducted a multicenter, retrospective cohort study by linking a quality assurance dataset to administrative health data in Ontario, Canada. Subjects were accrued between January 1, 2004 and July 9, 2013. Individuals were grouped into assisted peritoneal dialysis (family or home care assisted) or in-center hemodialysis on the basis of their first outpatient dialysis modality. Inverse probability of treatment weighting using a propensity score was used to create a sample in which the baseline covariates were well balanced.

RESULTS

The study included 872 patients in the in-center hemodialysis group and 203 patients in the assisted peritoneal dialysis group. Using an intention to treat approach, patients on assisted peritoneal dialysis had a similar hospitalization rate of 11.1 d/yr (95% confidence interval, 9.4 to 13.0) compared with 12.9 d/yr (95% confidence interval, 10.3 to 16.1) in the hemodialysis group (P=0.19). Patients on assisted peritoneal dialysis were more likely to be hospitalized for dialysis-related reasons (admitted for 2.4 d/yr [95% confidence interval, 1.8 to 3.2] compared with 1.6 d/yr [95% confidence interval, 1.1 to 2.3] in the hemodialysis group; P=0.04). This difference was partly explained by more hospital days because of peritonitis. Modality switching was associated with high rates of hospital days per year.

CONCLUSIONS

Assisted peritoneal dialysis was associated with similar rates of all-cause hospitalization compared with in-center hemodialysis. Patients on assisted peritoneal dialysis who experienced peritonitis and technique failure had high rates of hospitalization.

Technique failure in Korean incident peritoneal dialysis patients: a national population-based study

Background

Technique failure is an important issue for peritoneal dialysis (PD) patients. In this study, we aimed to analyze technique failure rate in detail and to determine the predictors for technique failure in Korea.

Methods

We identified all patients who had started dialysis between January 1, 2005, and December 31, 2008, in Korea, using the Korean Health Insurance Review and Assessment Service database. A total of 7,614 PD patients were included, and the median follow-up was 24.9 months.

Results

The crude incidence rates of technique failure in PD patients were 54.1 per 1,000 patient-years. The cumulative 1-, 2-, and 3-year technique failure rates of PD patients were 4.9%, 10.3%, and 15.6%, respectively. However, those technique failure rates by Kaplan–Meier analysis were overestimated compared with the values by competing risks analysis, and the differences increased with the follow-up period. In multivariate analyses, diabetes mellitus and Medical Aid as a crude reflection of low socioeconomic status were independent risk factors in both the Cox proportional hazard model and Fine and Gray subdistribution model. In addition, cancer was independently associated with a lower risk of technique failure in the Fine and Gray model.

Conclusion

Technique failure was a major concern in patients initiating PD in Korea, especially in diabetic patients and Medical Aid beneficiaries. The results of our study offer a basis for risk stratification for technique failure.

Overcoming the Underutilisation of Peritoneal Dialysis

Peritoneal dialysis is troubled with declining utilisation as a form of renal replacement therapy in developed countries. We review key aspects of therapy evidenced to have a potential to increase its utilisation. The best evidence to repopulate PD programmes is provided for the positive impact of timely referral and systematic and motivational predialysis education: average odds ratio for instituting peritoneal dialysis versus haemodialysis was 2.6 across several retrospective studies on the impact of predialysis education. Utilisation of PD for unplanned acute dialysis starts facilitated by implantation of peritoneal catheters by interventional nephrologists may diminish the vast predominance of haemodialysis done by central venous catheters for unplanned dialysis start. Assisted peritoneal dialysis can improve accessibility of home based dialysis to elderly, frail, and dependant patients, whose quality of life on replacement therapy may benefit most from dialysis performed at home. Peritoneal dialysis providers should perform close monitoring, preventing measures, and timely prophylactic therapy in patients judged to be prone to EPS development. Each peritoneal dialysis programme should regularly monitor, report, and act on key quality indicators to manifest its ability of constant quality improvement and elevate the confidence of interested patients and financing bodies in the programme.

Predictors of Transfer to Home Hemodialysis after Peritoneal Dialysis Completion

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BACKGROUND

The aim of the present study was to evaluate the predictors of transfer to home hemodialysis (HHD) after peritoneal dialysis (PD) completion. ♦

METHODS

All Australian and New Zealand patients treated with PD on day 90 after initiation of renal replacement therapy between 2000 and 2012 were included. Completion of PD was defined by death, transplantation, or hemodialysis (HD) for 180 days or more. Patients were categorized as "transferred to HHD" if they initiated HHD fewer than 180 days after PD had ended. Multivariable logistic regression was used to evaluate predictors of transfer to HHD in a restricted cohort experiencing PD technique failure; a competing-risks analysis was used in the unrestricted cohort. ♦

RESULTS

Of 10 710 incident PD patients, 3752 died, 1549 underwent transplantation, and 2915 transferred to HD, among whom 156 (5.4%) started HHD. The positive predictors of transfer to HHD in the restricted cohort were male sex [odds ratio (OR): 2.81], obesity (OR: 2.20), and PD therapy duration (OR: 1.10 per year). Negative predictors included age (OR: 0.95 per year), infectious cause of technique failure (OR: 0.48), underweight (OR: 0.50), kidney disease resulting from hypertension (OR: 0.38) or diabetes (OR: 0.32), race being Maori (OR: 0.65) or Aboriginal and Torres Strait Islander (OR: 0.30). Comparable results were obtained with a competing-risks model. ♦

CONCLUSIONS

Transfer to HHD after completion of PD is rare and predicted by patient characteristics at baseline and at the time of PD end. Transition to HHD should be considered more often in patients using PD, especially when they fulfill the identified characteristics.

High Peritoneal Glucose Exposure Is Associated with Increased Incidence of Relapsing and Recurrent Bacterial Peritonitis in Patients Undergoing Peritoneal Dialysis

Aim: We investigated the association of peritoneal glucose exposure and dialysis exchange number with peritonitis outcome in patients undergoing continuous ambulatory peritoneal dialysis (CAPD). Methods: The first episodes of bacterial peritonitis were retrospectively analyzed in 187 CAPD patients. Peritoneal glucose exposure was calculated based on PD prescription at the onset of peritonitis. Results: Patients with peritoneal glucose exposure ≤140 g/day showed a higher and complete cure rate of peritonitis (66 vs. 51.7%, p = 0.047), lower occurrence of relapsing/recurrent peritonitis (10.0 vs. 21.8%, p = 0.026) and catheter removal (14.0 vs. 26.4%, p = 0.033). Patients who exchanged more than three times every day demonstrated marginally higher catheter removal rate (24.1 vs. 13.0%, p = 0.085). Logistic analysis indicated that peritoneal glucose exposure >140 g/day was an independent predictor for relapsing/recurrent peritonitis (RR: 1.959, p = 0.042). Conclusion: High peritoneal glucose exposure is associated with increased incidence of relapsing/recurrent peritonitis in CAPD patients.