Ultrafiltration Patterns during Automated Peritoneal Dialysis: Findings and Insights to Peritoneal Physiology.

BACKGROUND: With the growing use of automated peritoneal dialysis (APD), it is important to improve our knowledge of the clinical patterns and physiology of APD treatment sessions. The ultrafiltration (UF) achieved during each cycle of an APD treatment is assumed to be relatively linear if the delivered prescription is the same. We set out to determine if that is indeed the case. METHODS: Single-center, cross-sectional study of prevalent PD patients. All adult APD patients (> 18 years of age), who had been on PD for >3 months, and >3 months on APD were included. Continuous ambulatory PD patients or those with peritonitis within 3 months of the consent date were excluded. Individual treatment data from 7 consecutive APD treatment sessions with consistent dialysate composition for each cycler exchange were collected for each subject. RESULTS: Thirty-nine subjects met the inclusion criteria and were enrolled. The probability of yielding a positive UF was 48.9% for cycle 1, rising to 90.5% by cycle 6. Adjusting for average dextrose concentration, dwell time, fill volume, solute transfer rate, and number of cycles, we observed that cycles 2 through 6 achieved progressively higher UF volumes than cycle 1 (p < 0.001). The first and last cycles demonstrated significantly different cycle UF volumes compared to a middle cycle (-230 ml and 277 ml, respectively, p < 0.001). CONCLUSIONS: We observed a consistent increase in UF volumes achieved per cycle over the course of an APD treatment session with numerous clinical and physiologic implications. This provides the foundation for future studies investigating peritoneal inter-cycle variations and membrane physiology.

Pay-for-Performance Incentives for Home Dialysis Use and Kidney Transplant.

Importance: The Centers for Medicare & Medicaid Services' mandatory End-Stage Renal Disease Treatment Choices (ETC) model, launched on January 1, 2021, randomly assigned approximately 30% of US dialysis facilities and managing clinicians to financial incentives to increase the use of home dialysis and kidney transplant. Objective: To assess the ETC's association with use of home dialysis and kidney transplant during the model's first 2 years and examine changes in these outcomes by race, ethnicity, and socioeconomic status. Design, Setting, and Participants: This retrospective cross-sectional study used claims and enrollment data for traditional Medicare beneficiaries with kidney failure from 2017 to 2022 linked to same-period transplant data from the United Network for Organ Sharing. The study data span 4 years (2017-2020) before the implementation of the ETC model on January 1, 2021, and 2 years (2021-2022) following the model's implementation. Exposure: Receiving dialysis treatment in a region randomly assigned to the ETC model. Main Outcomes and Measures: Primary outcomes were use of home dialysis and kidney transplant. A difference-in-differences (DiD) approach was used to estimate changes in outcomes among patients treated in regions randomly selected for ETC participation compared with concurrent changes among patients treated in control regions. Results: The study population included 724 406 persons with kidney failure (mean [IQR] age, 62.2 [53-72] years; 42.5% female). The proportion of patients receiving home dialysis increased from 12.1% to 14.3% in ETC regions and from 12.9% to 15.1% in control regions, yielding an adjusted DiD estimate of -0.2 percentage points (pp; 95% CI, -0.7 to 0.3 pp). Similar analysis for transplant yielded an adjusted DiD estimate of 0.02 pp (95% CI, -0.01 to 0.04 pp). When further stratified by sociodemographic measures, including age, sex, race and ethnicity, dual Medicare and Medicaid enrollment, and poverty quartile, there was not a statistically significant difference in home dialysis use across joint strata of characteristics and ETC participation. Conclusions and Relevance: In this cross-sectional study, the first 2 years of the ETC model were not associated with increased use of home dialysis or kidney transplant, nor changes in racial, ethnic, and socioeconomic disparities in these outcomes.

Trends, Outcomes, and Economic Implications of Peritoneal Dialysis-Associated Peritonitis Hospitalizations: A National Cohort Study.

INTRODUCTION: Peritoneal dialysis-associated peritonitis (PDAP) is a serious complication of peritoneal dialysis, associated with significant morbidity, modality transition, and mortality. Here, we provide an update on the national burden of this significant complication, highlighting trends in demographics, treatment practices, and in-hospital outcomes of PDAP from 2016 to 2020. METHODS: Utilizing a national all-payer dataset of hospitalizations in the USA, we conducted a retrospective cohort study of adult hospitalizations with a primary diagnosis of PDAP from 2016 to 2020. We analyzed demographic, clinical, and hospital-level data, focusing on in-hospital mortality, PD catheter removal, length of stay, and healthcare expenses. Multivariable logistic regression adjusted for demographic and clinical covariates was employed to identify risk factors associated with adverse outcomes. RESULTS: There was a stable burden of annual PDAP admissions from 2016 to 2020. Healthcare expenditures associated with PDAP were high, totaling over USD 75,000 per admission. Additionally, our data suggest geographic inconsistencies in treatment patterns, with treatment at western and teaching hospitals associated with increased rates of catheter removal relative to northeastern and non-teaching centers and a mean cost of nearly USD 55,000 more in Western states compared to Midwest states. 23.2% of episodes resulted in the removal of the PD catheter. Risk factors associated with adverse outcomes included older age, higher Charlson comorbidity index scores, peripheral vascular disease, and the need for vasopressors. CONCLUSION: PDAP is a major cause of mortality among PD patients, and there is a vital need for future studies to examine the impact of hospital location and teaching status on PDAP outcomes, which can inform treatment practices and resource allocation.

Clearing the air: a review of the effects of air pollution on dialysis outcomes.

PURPOSE OF REVIEW: An evolving body of literature indicates exposure to air pollutants is associated with adverse health outcomes in dialysis patients. As the prevalence of kidney disease increases, understanding the role of environmental agents on the health of dialysis patients is critical to reducing global morbidity and mortality. RECENT FINDINGS: We identified 16 publications that investigated associations between pollutants including particulate matter (PM 2.5 and PM 10 ), carbon monoxide (CO), nitrogen dioxide (NO 2 ), sulfur dioxide (SO 2 ), and ozone (O 3 ) and health outcomes among dialysis patients. Eight studies examined the effects of particulate matter (PM) and four studies examined the effects CO exposure on dialysis patients. Exposure to PM was consistently associated with outcomes including all-cause mortality and a smaller body of literature suggested relationships with subclinical outcomes. Exposure to CO was associated with all-cause mortality, generalized inflammation, and uremic pruritus. An additional four studies examined multiple pollutant exposures including NO 2 , SO 2 , and O 3 and reported associations with all-cause mortality in dialysis patients. SUMMARY: This review emphasized the nascent literature that demonstrates consistent relationships between air pollutant exposure and adverse outcomes among dialysis patients. Further research is needed to assess the impact of air pollutants, including how co-exposures will impact dialysis patient health.

Micrococcus Peritonitis Complicating Peritoneal Dialysis.

Peritonitis, a serious complication of peritoneal dialysis (PD), can be caused by opportunistic pathogens like Micrococcus species on rare occasions. We present a case of Micrococcus sp peritonitis in a 55-year-old female with end-stage kidney disease on continuous cycling peritoneal dialysis for one year who presented with cloudy effluent. Initial treatment against Micrococcus sp with vancomycin, gentamicin, and prophylactic oral nystatin was successful. However, one month later, the patient presented with abdominal pain and dialysate culture again grew Micrococcus sp. Treatment with vancomycin was unsuccessful in resolving culture positivity. The patient was transitioned to hemodialysis for non-medical reasons and then was later restarted on PD without further peritonitis episodes. Micrococcus sp peritonitis in PD poses treatment challenges due to limited guidelines. Intraperitoneal vancomycin is commonly used to target Micrococcus isolates although there is a high incidence of treatment failure. This case report highlights the need for continued reporting to enhance identification, prevention, and patient outcomes in Micrococcus sp peritonitis during PD.

Characteristics of registered research in peritoneal dialysis: Past and present.

Recent national policy changes in the United States and the continued growth of peritoneal dialysis (PD) as a therapy for end-stage kidney disease has renewed interest in this modality. The objective of this study was to describe the current landscape of PD clinical trials to assess trends and gaps in clinical research. An advanced search was completed through ClinicalTrials.gov, yielding 248 studies. Descriptive statistics and Fisher exact tests were used for statistical analysis. Most studies were completed (197, 79.4%), did not indicate a phase (143, 57.7%), were academically sponsored (156, 62.9%), or conducted in Asia (88, 35.5%). There has been overall growth in PD clinical trials since 1995. The type of phase was related to study location (p = 0.008). The type of study intervention was related to study recruitment status, sponsor type, and primary outcome (p = 0.030, p < 0.001, p < 0.001, respectively). Despite growth in PD research worldwide, more studies are being conducted outside the U.S., and static investment in U.S. government-sponsored PD research risks not achieving the goal of increasing availability of home dialysis.

Persistent peritonitis in peritoneal dialysis: a comphrenesive review of recurrent, relapsing, refractory, and repeat peritonitis.

Peritonitis is a major cause of morbidity and technique failure in patients receiving peritoneal dialysis. Complicated peritonitis that manifests as multiple or unresolving episodes is classified as refractory, recurrent, relapsing, or repeat peritonitis, and often possesses higher risk of technique failure and mortality as well as lower complete cure rates than primary or uncomplicated episodes. While these peritonitis subtypes affect a considerable portion of PD patients, details regarding their epidemiology, pathogenesis, diagnosis, clinical sequelae, and management have not yet been fully elucidated. Improved clinical awareness and understanding of complicated peritonitis subtypes is crucial to ensure optimal management for these patients; thus, we consolidate and report the pertinent findings of recent literature on these four entities.

Heating up: climate change and the threat to human health.

PURPOSE OF REVIEW: This review discusses the urgency of addressing human-caused climate change and its impacts on health and the environment. RECENT FINDINGS: The latest evidence shows that current climate changes are primarily attributable to greenhouse gas emissions from human industrial activity. Exceeding 1.5°C of warming above preindustrial levels is projected to increase extreme weather events, increase rates of heat-related morbidity and mortality and vector-borne disease, exacerbate food and water insecurity, harm biodiversity and agriculture, displace communities, and disproportionately impact disadvantaged groups. SUMMARY: Urgent action is required to curb emissions, enact adaptation strategies, and promote climate justice. The healthcare sector must reduce its ecological footprint and prepare systems and workers to address climate change's health effects. Further research should support climate solutions while promoting health equity and environmental justice.

Impact of COVID-19 on maintenance peritoneal dialysis patients and providers: A review.

The COVID-19 pandemic exerted complex pressures on the nephrology community. Despite multiple prior reviews on acute peritoneal dialysis during the pandemic, the effects of COVID-19 on maintenance peritoneal dialysis patients remain underexamined. This review synthesizes and reports findings from 29 total cases of chronic peritoneal dialysis patients with COVID-19, encompassing 3 case reports, 13 case series, and 13 cohort studies. When available, data for patients with COVID-19 on maintenance hemodialysis are also discussed. Finally, we present a chronological timeline of evidence regarding the presence of SARS-CoV-2 in spent peritoneal dialysate and explore trends in telehealth as they relate to peritoneal dialysis patients during the pandemic. We conclude that the COVID-19 pandemic has underscored the efficacy, flexibility, and utility of peritoneal dialysis.

Hospitalization in maintenance peritoneal dialysis: a review.

Although hemodialysis continues to be the dominant form of dialysis in the United States, peritoneal dialysis rates continue to rise both nationally and worldwide. Peritoneal dialysis offers patients increased flexibility due to the ability to dialyze at home, leading to potential quality of life benefits for patients. However, questions exist regarding clinical outcomes in patients on peritoneal dialysis and the literature has not recently been reviewed. This review examines hospitalizations within patients utilizing peritoneal dialysis, including comparison to other dialysis modalities. Much heterogeneity exists within the literature, often explained by patient population. Recent data show all-cause, cardiovascular, and infection-related hospitalizations to be high in patients on peritoneal dialysis, although data variation limits conclusions in comparison to other modalities. This review found there is insufficient evidence to suggest admission rates are different in peritoneal dialysis than in-center hemodialysis. While the rate is similar to infectious causes, most studies report cardiovascular complications to be the leading cause of hospitalization. Some evidence suggests that cardiovascular hospitalizations occur at a higher rate in peritoneal dialysis, but further studies are required. The infection-related hospitalization rate appears to be higher in peritoneal dialysis due to rates of peritonitis, but rates of life-threatening bacteremia are lower. Differences in reporting of hospital days vs. length of stay challenge the interpretability of length of stay data between modalities, but patients on PD may spend more days per year in the hospital. In summary, hospitalization is highly prevalent in patients on peritoneal dialysis and few definitive conclusions can be drawn in comparison to other dialysis modalities. In eligible patient populations who desire increased flexibility, peritoneal dialysis is a reasonable modality choice.

Peritoneal equilibration testing: Your questions answered.

The peritoneal equilibration test (PET), first described in 1987, is a semiquantitative assessment of peritoneal transfer characteristics in patients undergoing peritoneal dialysis. It is typically performed as a 4-h exchange using 2.27/2.5% dextrose dialysate with serial measurements of blood and dialysate creatinine, urea, and glucose concentrations. The percentage absorption of glucose and D/P creatinine ratio are used to determine peritoneal solute transfer rates. It is used to both help guide peritoneal dialysis prescriptions and to prognosticate. There are several derivative tests which have been described in the literature. In this review, we describe the original PET, the various iterations of the PET, the information gleaned, and the use in the setting of poor solute clearance and in the diagnosis of membrane dysfunction, and limitations of the PET.

Encapsulating peritoneal sclerosis: Your questions answered.

Encapsulating peritoneal sclerosis (EPS) is a clinical syndrome hallmarked by the formation of a fibrous cocoon encapsulating the bowel resulting in morbidity and mortality. EPS is most frequently associated with peritoneal dialysis (PD), particularly with its discontinuation. While EPS is one of the most feared complications of PD, the majority of patients receiving PD will not go on to develop EPS. Risk factors for development include time on PD, some types of peritonitis and discontinuation of PD. Owing to its rarity, much of the knowledge of EPS comes from case series and registries and treatments are extrapolated from low-quality evidence. Malnutrition is a significant driver of mortality, and nutritional support is critical in management. We present a case of EPS and frequently asked questions including the definition, diagnosis, epidemiology, pathophysiology, risk factors, role of infection, management and roles of nutrition and surgery.

Nutrition in Peritoneal Dialysis.

The use of peritoneal dialysis (PD) has been associated with improved quality of life, cost-effectiveness, and better outcomes for patients with kidney failure. However, many patients utilizing PD for replacement therapy face numerous nutritional hurdles. As the use of PD continues to increase worldwide, malnutrition has become an increasingly recognized concern for patients undergoing PD. The nephrology community needs to recognize and treat malnutrition to promote optimal nutritional states for our patients. In this review, we discuss several factors that contribute to malnutrition and protein-energy wasting and explore the benefits and limitations of nutritional parameters used to assess protein-calorie malnutrition. We also emphasize updated guidelines on daily caloric, protein, and micronutrient recommendations, as well as their effects on electrolyte homeostasis.

Rothia Mucilaginosa Peritonitis Complicating Peritoneal Dialysis.

For the 11% of dialysis patients worldwide who receive peritoneal dialysis (PD) to treat their end-stage kidney disease (ESKD), recent PD-associated peritonitis is estimated to contribute to 5-30% of reported mortality.1,2 These infections are most commonly caused by coagulase-negative Staphylococcus (32%), followed by culture-negative peritonitis (16%), and the timely identification and targeted treatment of peritonitis is critical to avoid complications such as PD catheter removal.3 Here, we present a case of atypical Rothia mucilaginosis peritonitis in a PD patient.

Periprocedural Peritonitis Prophylaxis: A Summary of the Microbiology and the Role of Systemic Antimicrobials.

BACKGROUND: Peritonitis is a leading complication of peritoneal dialysis (PD). One strategy that the International Society for Peritoneal Dialysis (ISPD) has used to help mitigate the morbidity and mortality associated with peritonitis is through prevention, including antibiotic prophylaxis utilization in high-risk situations. The aim of this study is to summarize our current understanding of postprocedural peritonitis and discuss the existing data behind periprocedural antibiotic prophylaxis, focusing primarily on PD catheter insertion, dental procedures, colonoscopies, upper endoscopies with gastrostomy, and gynecologic procedures. SUMMARY: The ISPD currently recommends intravenous antibiotics prior to PD catheter insertion, colonoscopies, and invasive gynecologic procedures, though prophylaxis has only demonstrated benefit in a prospective, randomized control setting for PD catheter insertion. However, multiple retrospective studies exist that support the use of antibiotic prophylaxis for the other 2 procedures. No specific antibiotic regimen has been established as most optimal to prevent peritonitis for any of the 3 procedures. Antibiotic coverage should include the Enterobacteriaceae family, as well as Gram-positive organisms commonly found on the skin flora for PD catheter insertion, anaerobes for colonoscopies, and common organisms from the urogenital flora in gynecologic procedures. Additionally, the ISPD currently recommends oral amoxicillin prior to dental procedures. There is currently no ISPD recommendation to provide antibiotic prophylaxis prior to an upper endoscopy with or without gastrostomy, though this is a potential area for research. KEY MESSAGES: PD patients are at high risk for developing peritonitis after typical procedures. Antibiotic prophylaxis is a potential strategy that the ISPD utilizes to prevent these infections. However, further research needs to be done to determine the optimal antibiotic regimen.

Forget the phosphorus: A case of hypervitaminosis D-induced symptomatic hypercalcemia.

Hypercalcemia is a frequently encountered electrolyte abnormality with a well-described differential diagnosis and classic algorithm for evaluation. The treatment for hypercalcemia is dependent on the underlying etiology. Hypervitaminosis D is an uncommon cause of hypercalcemia, but the use of vitamin D supplementation has expanded and case reports of supplemental vitamin D induced hypercalcemia have become more frequent. We present a case of hypervitaminosis D-induced altered mental status where diagnosis was delayed and additional invasive testing was performed due to an assumption regarding phosphatemia.