Project description:BackgroundPeritoneal dialysis (PD) is an important modality of renal replacement therapy (RRT). Peritonitis and ultrafiltration failure are complications that have a long-term impact on PD patients. Besides touch contamination, procedural errors and clinical reasons of peritonitis, contaminants, and constituents of peritoneal dialysis fluids (PDFs) have been implicated in causing peritonitis and ultrafiltration failure. This study was aimed to test the PDFs in India for the presence of migratory plastics.Materials and methodsPDFs from the two manufacturers in India were tested using liquid chromatography mass spectrometry (LCMS) and gas chromatography mass spectrometry (GCMS) with headspace analysis (volatile compounds) and pyrolysis of plastics (polymer compounds). The storage conditions and handling were uniform.ResultsThe results revealed impurities of acetate compounds and aldehyde derivatives of glucose degradation products (GDPs) with contaminants and leachable plastics. There were high levels of GDP derivative in the form of 5-hydroxymethylfurfural compounds (5-HMF). The analysis revealed the presence of plastic softeners in very high concentrations.ConclusionThe study unmasks the presence of chemicals and GDPs that can be implicated in pathogenesis of sterile peritonitis and ultrafiltration failure. The study demonstrated the presence of leachable plastics. In conclusion, LCMS and GCMS studies can be used to test PDFs for unwanted chemicals prior to human use.
Project description:The use of an incremental peritoneal dialysis (PD) strategy in a large contemporary patient population has not been described.We report the use of this strategy in clinical practice, the prescriptions required, and the clearances achieved in a large center which has routinely used this approach for more than 10 years.This is a cross-sectional observational study.A single large Canadian academic center.This study collected data on 124 prevalent PD patients at a single Canadian academic center.The proportion of patients who achieve the clearance target on a low clearance or incremental PD prescription; the actual PD prescriptions and consequent total, peritoneal, and renal urea clearances [Kt/V] achieved; and patient and technique survival and peritonitis rate in comparison with national and international reports.Of the 124 prevalent PD patients in this PD unit, 106 (86%) were achieving the Kt/V target, and of these, 54 (44% of all patients) were doing so using incremental PD prescriptions. Fifty of these incremental PD patients were using automated PD (APD) with either no day dwell (68%) or less than 7 days a week treatment (12%) or both (20%). Patient survival in our PD unit was not different from that reported in Canada as a whole. Peritonitis rates were better than internationally recommended standards.This is an observational study with no randomized control group.Incremental PD is feasible in a contemporary PD population treated mainly with APD. Almost half of the patients were able to achieve clearance targets while receiving less onerous and less costly low clearance prescriptions. We suggest that incremental PD should be widely used as a cost-effective strategy in PD.
Project description:Polyvinyl chloride (PVC) is the world's third-most widely manufactured thermoplastic, but has the lowest recycling rate. The development of PVC-like plastics that can be depolymerized back to monomer contributes to a circular plastic economy, but has not been accessed. Here, we develop a series of chemically recyclable plastics from the reversible copolymerization of cyclic anhydride with chloral. The copolymerization is highly efficient through the anionic or cationic mechanism under mild conditions, yielding polyesters with tunable structure and properties from multiple commercial monomers. Notably, these polyesters manifest mechanical properties comparable to PVC and polystyrene. Meanwhile, such polyesters are flame-retardant like PVC due to high chloride content. Of significance, these polyesters can be depolymerized back to starting monomers at high temperatures owing to the reversibility of the copolymerization, leading to a circular economy. Overall, the readily available monomers, simple synthesis, advantageous performance, and practical recyclability make the polymers promising for applications.
Project description:Thermosets-polymeric materials that adopt a permanent shape upon curing-have a key role in the modern plastics and rubber industries, comprising about 20 per cent of polymeric materials manufactured today, with a worldwide annual production of about 65 million tons1,2. The high density of crosslinks that gives thermosets their useful properties (for example, chemical and thermal resistance and tensile strength) comes at the expense of degradability and recyclability. Here, using the industrial thermoset polydicyclopentadiene as a model system, we show that when a small number of cleavable bonds are selectively installed within the strands of thermosets using a comonomer additive in otherwise traditional curing workflows, the resulting materials can display the same mechanical properties as the native material, but they can undergo triggered, mild degradation to yield soluble, recyclable products of controlled size and functionality. By contrast, installation of cleavable crosslinks, even at much higher loadings, does not produce degradable materials. These findings reveal that optimization of the cleavable bond location can be used as a design principle to achieve controlled thermoset degradation. Moreover, we introduce a class of recyclable thermosets poised for rapid deployment.
Project description:BackgroundKidney failure prevalence is increasing in older patients for whom dialysis initiation can be challenging. Assisted peritoneal dialysis (PD), where PD is performed with the help of a healthcare worker, can facilitate PD for frailer patients who may not be candidate otherwise.ObjectivesThis study aimed to assess the feasibility of implementing the first pilot assisted PD program in Quebec (Canada) and to evaluate the characteristics and outcomes of the PD cohort before and after assisted PD availability.DesignObservational retrospective cohort study.Setting and populationAll adult patients initiating PD between 2015 and 2020 in a single-center dialysis unit were included.MeasurementsIncidence, characteristics, and outcomes of patients with PD were compared between (1) the "pre" (2015-2017) and the "post" assisted PD era (2018-2020) and (2) patients with assisted PD and independent PD in the more recent period.MethodsThe primary outcome was peritonitis rate over the first year. Secondary outcomes included hospitalization, transfers to in-center hemodialysis (HD) and mortality.ResultsOverall, 124 patients initiated PD with an annual incidence of 17 ± 3 patients during the "pre" and 24 ± 8 patients during the "post" assisted PD era (P = .18). First-year peritonitis rate was similar over the 2 eras. Years of PD initiation and use of assisted PD were not associated with risk peritonitis (over total follow-up) after adjustment. Adjusted hazard of transfer to HD or death was higher during the "post" era (hazard ratio [HR]: 2.77; 95% confidence interval [CI]: 1.42-5.58). Seventeen patients received assisted PD including 13 (18%) of the 72 patients initiated between 2018 and 2020. Patients with assisted PD were older than those with independent PD (72 [64-84] vs. 59 [47-67], P = .006) and received assistance for 0.8 (0.4-1.5) years. When comparing assisted and independent cohorts, there were no differences in crude rates of peritonitis or hospitalization.LimitationsSingle-center study with small sample size.ConclusionThis study shows the feasibility of implementing an assisted PD program, with favorable overall outcomes including similar rates of peritonitis during the first year after PD initiation.
Project description:BackgroundHome dialysis utilization is lower among veterans than in the general US population. Several sociodemographic factors and comorbidities contribute to peritoneal dialysis (PD) underutilization. In 2019, the Veterans Health Administration (VHA) Kidney Disease Program Office convened a PD workgroup to address this concern.ObservationsThe PD workgroup was explicitly concerned by the limited availability of PD within the VHA, which frequently requires veterans to transition kidney disease care from US Department of Veterans Affairs medical centers (VAMCs) to non-VHA facilities when they progress from chronic kidney disease to end-stage kidney disease, causing fragmentation of care. Since the administrative requirements and infrastructure of VAMCs vary, the workgroup focused its deliberations on synthesizing a standard process for evaluating the feasibility and establishing a new PD program within any individual VAMC. A 3-phased approach was envisioned, beginning with ascertainment of prerequisites, leading to an examination of the clinical and financial feasibility through the process of data gathering and synthesis, culminating in a business plan that translates the previous 2 steps into an administrative document necessary for obtaining VHA approvals.ConclusionsVAMCs can use the guide presented here to improve therapeutic options for veterans with kidney failure by establishing a new or restructured PD program.
Project description:IntroductionAs interest for home dialysis is growing, knowledge of comparative clinical outcomes between peritoneal dialysis (PD) and home hemodialysis (HHD) would help to better inform shared decision making with patients and caregivers during modality discussion. This study aimed to assess differences in risk of mortality and technique failure in an incident home dialysis cohort and, specifically, to assess change in this association through eras.MethodsAll adults patients initiating PD or HHD, in Canada (excluding Quebec), within 365 days after kidney replacement therapy (KRT) initiation between 2000 and 2013 were included (administrative censoring 31 December 2014). Mortality and treatment failure (transfer to another modality for >90 days or death) were assessed in a multivariable Cox proportional hazard model, with prespecified stratification based on the year of KRT initiation.ResultsThe study included 959 HHD and 15,469 PD patients. Compared with incident PD, incident HHD was associated with a lower risk of mortality (adjusted hazard ratio [aHR] = 0.64, 95% confidence interval [CI] = 0.53-0.78), and treatment failure (aHR = 0.52, 95% CI = 0.45-0.60). These lower risks of mortality with HHD were more pronounced for older cohorts (2000-2005: aHR = 0.47, 95% CI = 0.31-0.70; 2006-2010: aHR = 0.70, 95% CI = 0.54-0.89) and not significantly different in the most recent era (2011-2013: aHR = 0.86, 95% CI = 0.51-1.47).ConclusionIn Canadian incident KRT patients, HHD was associated with appreciably lower risks of mortality and treatment failure compared to PD, although this association appeared to be attenuated in the most contemporary era.