Associations of neutral pH, low-GDP peritoneal dialysis solutions with patient survival, transfer to haemodialysis and peritonitis.

BACKGROUND: Peritoneal dialysis (PD) solutions containing low levels of glucose degradation products (GDPs) are associated with attenuation of peritoneal membrane injury and vascular complications. However, clinical benefits associated with neutral-pH, low-GDP (N-pH/L-GDP) solutions remain unclear. METHODS: Using data from the Australia and New Zealand Dialysis and Transplant Registry, we examined the associations between N-pH/L-GDP solutions and all-cause mortality, cause-specific mortality, transfer to haemodialysis (HD) for ≥30 days and PD peritonitis in adult incident PD patients in Australia and New Zealand between 1 January 2005 and 31 December 2020 using adjusted Cox regression analyses. RESULTS: Of 12 814 incident PD patients, 2282 (18%) were on N-pH/L-GDP solutions. The proportion of patients on N-pH/L-GDP solutions each year increased from 11% in 2005 to 33% in 2017. During the study period, 5330 (42%) patients died, 4977 (39%) experienced transfer to HD and 5502 (43%) experienced PD peritonitis. Compared with the use of conventional solutions only, the use of any form of N-pH/L-GDP solution was associated with reduced risks of all-cause mortality {adjusted hazard ratio [aHR] 0.67 [95% confidence interval (CI) 0.61-0.74]}, cardiovascular mortality [aHR 0.65 (95% CI 0.56-0.77)], infection-related mortality [aHR 0.62 (95% CI 0.47-0.83)] and transfer to HD [aHR 0.79 (95% CI 0.72-0.86)] but an increased risk of PD peritonitis [aHR 1.16 (95% CI 1.07-1.26)]. CONCLUSIONS: Patients who received N-pH/L-GDP solutions had decreased risks of all-cause and cause-specific mortality despite an increased risk of PD peritonitis. Studies assessing the causal relationships are warranted to determine the clinical benefits of N-pH/L-GDP solutions.

Sex Disparity in Cause-Specific and All-Cause Mortality Among Incident Dialysis Patients.

RATIONALE & OBJECTIVE: Early mortality rates of female patients receiving dialysis have been, at times, observed to be higher than rates among male patients. The differences in cause-specific mortality between male and female incident dialysis patients with kidney failure are not well understood and were the focus of this study. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: Incident patients who had initiated dialysis in Australia and New Zealand in 1998-2018. EXPOSURE: Sex. OUTCOMES: Cause-specific and all-cause mortality while receiving dialysis, censored for kidney transplant. ANALYTICAL APPROACH: Adjusted cause-specific proportional hazards models, focusing on the first 5 years following initiation of dialysis. RESULTS: Among 53,414 patients (20,876 [39%] female) followed for a median period of 2.8 (IQR, 1.3-5.2) years, 27,137 (51%) died, with the predominant cause of death attributed to cardiovascular disease (18%), followed by dialysis withdrawal (16%). Compared with male patients, female patients were more likely to die in the first 5 years after dialysis initiation (adjusted hazard ratio [AHR], 1.08 [95% CI, 1.05-1.11]). Even though female patients experienced a lower risk of cardiovascular disease-related mortality (AHR, 0.93 [95% CI, 0.89-0.98]) than male patients, they experienced a greater risk of infection-related (AHR, 1.20 [95% CI, 1.10-1.32]) and dialysis withdrawal-related (AHR, 1.19 [95% CI, 1.13-1.26]) mortality. LIMITATIONS: Possibility of residual and unmeasured confounders. CONCLUSIONS: Compared with male patients, female patients had a higher risk of all-cause mortality in the first 5 years after dialysis initiation, a difference driven by higher rates of mortality from infections and dialysis withdrawals. These findings may inform the study of sex differences in mortality in other geographic settings.

Temporal changes and risk factors for death from early withdrawal within 12 months of dialysis initiation-a cohort study.

BACKGROUND: Mortality risk is high soon after dialysis initiation in patients with kidney failure, and dialysis withdrawal is a major cause of early mortality, attributed to psychosocial or medical reasons. The temporal trends and risk factors associated with cause-specific early dialysis withdrawal within 12 months of dialysis initiation remain uncertain. METHODS: Using data from the Australia and New Zealand Dialysis and Transplant Registry, we examined the temporal trends and risk factors associated with mortality attributed to early psychosocial and medical withdrawals in incident adult dialysis patients in Australia between 2005 and 2018 using adjusted competing risk analyses. RESULTS: Of 32 274 incident dialysis patients, 3390 (11%) experienced death within 12 months post-dialysis initiation. Of these, 1225 (36%) were attributed to dialysis withdrawal, with 484 (14%) psychosocial withdrawals and 741 (22%) medical withdrawals. These patterns remained unchanged over the past two decades. Factors associated with increased risk of death from early psychosocial and medical withdrawals were older age, dialysis via central venous catheter, late referral and the presence of cerebrovascular disease; obesity and Asian ethnicity were associated with decreased risk. Risk factors associated with early psychosocial withdrawals were underweight and higher socioeconomic status. Presence of peripheral vascular disease, chronic lung disease and cancers were associated with early medical withdrawals. CONCLUSIONS: Death from dialysis withdrawal accounted for >30% of early deaths in kidney failure patients initiated on dialysis and remained unchanged over the past two decades. Several shared risk factors were observed between mortality attributed to early psychosocial and medical withdrawals.

Utility of 'back-up' arterio-venous fistulae in patients on peritoneal dialysis and use of haemodialysis catheters.

BACKGROUND: Patients undergoing peritoneal dialysis may require unanticipated transfer to haemodialysis. Back up fistula are often created in selected patients. These may help reduce the infective burden of haemodialysis (HD) catheter. AIM: To study the utility of back-up arterio-venous fistulae (AVF) in patients initiated on peritoneal dialysis (PD) and to determine the rates of HD catheter use in patients requiring conversion to HD. METHODS: Data on HD transfer and HD catheter usage were retrospectively analysed in all patients initiating PD between January 2010 and December 2014 at Royal Adelaide Hospital (RAH; universal back-up AVF creation at PD commencement) and Princess Alexandra Hospital (PAH; selective back-up AVF creation in 'high risk' patients). RESULTS: A total of 374 patients initiated PD during the study period: 142 in RAH group and 232 in PAH group. The groups were reasonably comparable, except that RAH patients were more likely to be older, Caucasian and diabetic. Transfer to HD occurred in 33 (23%) patients in RAH group and 99 (43%) in the PAH group with respective median times to HD transfer of 289 and 295 days. HD catheter usage was required at the time of HD transfer in 11 (33%) patients at RAH and 64 (65%) in patients at PAH (P < 0.001). AVF complications occurred in 13 (9%) patients in RAH group (fistuloplasty n = 8, transposition n = 2, ligation due to ischaemia n = 2 and construction of new AVF n = 1). CONCLUSION: Patients undergoing PD frequently require urgent unanticipated transfer to HD and back-up AVF can be successfully utilised in this setting in the majority of cases, which in turn can reduce the infective burden of HD catheter exposure.

Differences in peritoneal dialysis technique survival between patients treated with peritoneal dialysis systems from different companies.

BACKGROUND: A number of peritoneal dialysis (PD) systems are available but there have been few studies comparing them. The aim of this study was to examine technique failure and patient survival between different PD company systems. METHODS: The study included all patients who commenced PD between 1995 and 2014 in Australia and New Zealand. Groups were compared according to the initial PD company system that they received. The primary outcome was a composite of PD technique failure and death. RESULTS: A total of 16 575 patients commenced PD using systems manufactured by Baxter [n = 13 438 (81%)], Fresenius Medical Care [n = 2848 (17%)] or Gambro [n = 289 (2%)]. Of these, 11 870 (72%) developed technique failure, including 5421 (33%) who died. The median time to technique failure or death for all patients was 625 [interquartile range (IQR) 318-1114] days: 629.5 (IQR 321-1121) days with Baxter, 620.5 (IQR 311-1069) days with Fresenius Medical Care and 538 (IQR 272-1001) days with Gambro systems (P = 0.023). There was a statistically significant increase in technique failure or mortality rates in patients on Gambro {adjusted incidence rate ratio [IRR] 1.46 [95% confidence interval (CI) 1.33-1.62]} and Fresenius [adjusted IRR 1.10 (95% CI 1.01-1.19)] systems compared with Baxter systems. No difference in patient survival was observed between the three PD systems. CONCLUSIONS: PD systems manufactured by different companies may be associated with important differences in PD technique survival. This needs to be confirmed with adequately powered, prospective randomized controlled clinical trials.

Risk Predictors and Causes of Technique Failure Within the First Year of Peritoneal Dialysis: An Australia and New Zealand Dialysis and Transplant Registry (ANZDATA) Study.

BACKGROUND: Concern regarding technique failure is a major barrier to increased uptake of peritoneal dialysis (PD), and the first year of therapy is a particularly vulnerable time. STUDY DESIGN: A cohort study using competing-risk regression analyses to identify the key risk factors and risk periods for early transfer to hemodialysis therapy or death in incident PD patients. SETTING & PARTICIPANTS: All adult patients who initiated PD therapy in Australia and New Zealand in 2000 through 2014. PREDICTORS: Patient demographics and comorbid conditions, duration of prior renal replacement therapy, timing of referral, PD modality, dialysis era, and center size. OUTCOMES: Technique failure within the first year, defined as transfer to hemodialysis therapy for more than 30 days or death. RESULTS: Of 16,748 patients included in the study, 4,389 developed early technique failure. Factors associated with increased risk included age older than 70 years, diabetes or vascular disease, prior renal replacement therapy, late referral to a nephrology service, or management in a smaller center. Asian or other race and use of continuous ambulatory PD were associated with reduced risk, as was initiation of PD therapy in 2010 through 2014. Although the risk for technique failure due to death or infection was constant during the first year, mechanical and other causes accounted for a greater number of cases within the initial 9 months of treatment. LIMITATIONS: Potential for residual confounding due to limited data for residual kidney function, dialysis prescription, and socioeconomic factors. CONCLUSIONS: Several modifiable and nonmodifiable factors are associated with early technique failure in PD. Targeted interventions should be considered in high-risk patients to avoid the consequences of an unplanned transfer to hemodialysis therapy or death.

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.

Uptake and Outcomes of Peritoneal Dialysis among Aboriginal and Torres Strait Islander People: Analysis of Registry Data.

Introduction: Peritoneal dialysis (PD) enables people to use kidney replacement therapy (KRT) outside of healthcare-dependent settings, a strong priority of Aboriginal and Torres Strait Islander people. Methods: We undertook an observational study analyzing registry data to describe access to PD and its outcome as the first KRT among Aboriginal and Torres Strait Islander people between January 1, 2004 and December 31 2020. Results: Out of 4604 Aboriginal and Torres Strait Islander people, reflecting 10.4% of all Australians commencing KRT, PD was the first KRT modality among 665 (14.4%). PD utilization was 17.2% in 2004 to 2009 and 12.7% in 2016 to 2020 (P = 0.002); 1105 episodes of peritonitis were observed in 413 individuals, median of 3 (interquartile range [IQR], 2-5) episodes/patient. The crude peritonitis rate was 0.53 (95% confidence interval [CI], 0.50-0.56) episodes/patient-years without any significant changes over time. The median time to first peritonitis was 1.1 years. A decrease in the peritonitis incidence rate ratio (IRR) was observed in 2016 to 2020 (IRR, 0.63 [95% CI, 0.52-0.77], P < 0.001) compared to earlier eras (2010-2015: IRR, 0.90 [95% CI, 0.76-1.07], P = 0.23; Ref: 2004-2009). The cure rates decreased from 80.0% (n = 435) in 2004 to 2009, to 70.8% (n = 131) in 2016 to 2020 (P < 0.001). Conclusion: Aboriginal and Torres Strait Islander people who utilized PD as their first KRT during 2004 to 2020 recorded a higher peritonitis rate than the current benchmark of 0.4 episodes/patient-years. The cure rates have worsened recently, which should be a big concern. There is an exigent need to address these gaps in kidney care for Aboriginal and Torres Strait Islander people.

Association of Peritonitis With Cardiovascular Mortality Over Time in the Peritoneal Dialysis Population: An Australia and New Zealand Dialysis and Transplant Registry Study.

Introduction: Though peritonitis is associated with increased mortality in patients receiving peritoneal dialysis (PD), its association with cardiovascular mortality remains uncertain. Methods: The study participants included adult patients (≥18 years old) commencing PD in Australia (from October 2003 to December 2019) using the Australia and New Zealand Dialysis and Transplant (ANZDATA) registry. Association between peritonitis and cardiovascular mortality was evaluated using Cox proportional hazards analysis and competing risks analysis. Associations between peritonitis rates between different eras and cardiovascular mortality were also compared using Jointpoint regression model to determine the time point when a significant change in peritonitis trend occurred to define the era for cardiovascular mortality. Subgroup analysis dividing the groups into 0, 1 and ≥2 episodes of peritonitis and sensitivity analysis censoring at 90 days post-transfer to hemodialysis (HD) were performed. Results: The study included 9699 incident PD patients. The overall peritonitis rate was 0.37 episodes per patient-year and declined by 4.7% (95% confidence interval [CI] 3.6-5.8%) during the study period. Peritonitis was associated with increased cardiovascular mortality risk (subdistribution hazard ratio [SHR] 1.53, 95% CI 1.39-1.69, P < 0.001) with increasing peritonitis episodes associated with higher risk (1 episode of peritonitis SHR 1.41, 95%CI 1.24-1.61; ≥2 episodes of peritonitis SHR 1.69, 95% CI 1.47-1.93, P < 0.001). Patients who commenced PD between 2012 and 2019 had a lower risk of cardiovascular mortality (SHR 0.60, 95% CI 0.50-0.72, P < 0.001), compared to patients who commenced between 2003 and 2011. Results were consistent in the sensitivity analysis. Conclusion: Peritonitis is independently associated with an increased risk of cardiovascular mortality, and the association is episode-dependent. Prevention and adequate treatment of PD peritonitis may improve cardiovascular outcomes among patients receiving PD.