Venous excess ultrasonography (VExUS) captures dynamic changes in volume status surrounding hemodialysis: A multicenter prospective observational study.

Background: The evaluation of volume status is essential to clinical decision-making, yet multiple studies have shown that physical exam does not reliably estimate a patient's intravascular volume. Venous excess ultrasound score (VExUS) is an emerging volume assessment tool that utilizes inferior vena cava (IVC) diameter and pulse-wave Doppler waveforms of the portal, hepatic and renal veins to evaluate venous congestion. A point-of-care ultrasound exam initially developed by Beaubein-Souligny et al., VExUS represents a reproducible, non-invasive and accurate means of assessing intravascular congestion. VExUS has recently been validated against RHC-the gold-standard of hemodynamic evaluation for volume assessment. While VExUS scores were shown to correlate with elevated cardiac filling pressures (i.e., right atrial pressure (RAP) and pulmonary capillary wedge pressure (PCWP)) at a static point in time, the ability of VExUS to capture dynamic changes in volume status has yet to be elucidated. We hypothesized that paired VExUS examinations performed before and after hemodialysis (HD) would reflect changes in venous congestion in a diverse patient population. Methods: Inpatients with end-stage renal disease undergoing intermittent HD were evaluated with transabdominal VExUS and lung ultrasonography before and following HD. Paired t-tests were conducted to assess differences between pre-HD and post-HD VExUS scores, B-line scores and dyspnea scores. Results: Fifty-six patients were screened for inclusion in this study. Ten were excluded due to insufficient image quality or incomplete exams, and forty-six patients (ninety-two paired ultrasound exams) were included in the final analysis. Paired t-test analysis of pre-HD and post-HD VExUS scores revealed a mean VExUS grade change of 0.82 (p<0.001) on a VExUS scale ranging from 0 to 4. The mean difference in B-line score following HD was 0.8 (p=0.001). There was no statistically significant difference in subjective dyspnea score (p=0.41). Conclusions: Large-volume fluid removal with HD was represented by changes in VExUS score, highlighting the utility of the VExUS exam to capture dynamic shifts in intravascular volume status. Future studies should evaluate change in VExUS grade with intravenous fluid or diuretic administration, with the ultimate goal of evaluating the capacity of a standardized bedside ultrasound protocol to guide inpatient volume optimization.

Rapid and Effective Treatment of Peritonitis in Peritoneal Dialysis Patients with Intravenous Dalbavancin.

BACKGROUND Peritonitis is a complication associated with peritoneal dialysis (PD), which carries a significant morbidity and mortality risk. Empiric therapy must include coverage of gram-positive organisms; vancomycin is a recommended treatment option, particularly when MRSA infection is a risk. Vancomycin is cumbersome for patients, requiring therapeutic drug monitoring and re-administration by a healthcare provider. Dalbavancin, administered as a one-time intravenous dose, is a convenient potential treatment option for PD patients to cover gram-positive organisms without the need for routine drug monitoring. CASE REPORT We present 2 patients effectively treated with dalbavancin for infectious peritonitis. The first patient, a 73-year-old woman with end-stage renal disease (ESRD) on PD, presented to the hospital with fever, elevated white blood cells (WBCs), and cloudy peritoneal fluid with elevated nucleated cell counts (88% neutrophils). This patient was given 1 dose of 1500 mg IV dalbavancin. Within 3 days, her fever resolved, WBCs returned to normal, and peritoneal fluid results improved. The second patient was a 36-year-old woman presenting to an outpatient clinic with abdominal pain and cloudy peritoneal fluid with elevated nucleated cell counts (53% neutrophils) treated with dalbavancin 1500 mg IV once. Within 4 days, this patient's pain had resolved, and peritoneal fluid results returned to baseline. No adverse effects were noted for either patient. CONCLUSIONS These cases illustrate the potential of dalbavancin as a convenient option for patients with PD-associated peritonitis. Both patients demonstrated rapid and complete response to a single dose of dalbavancin without complications. Further prospective studies are needed to establish dalbavancin as an option for peritonitis.

Hepcidin Removal during Continuous Renal Replacement Therapy.

INTRODUCTION: Patients with acute kidney injury (AKI) or end stage kidney disease (ESKD) may require continuous renal replacement therapy (CRRT) as a supportive intervention. While CRRT is effective at achieving solute control and fluid balance, the indiscriminate nature of this procedure raises the possibility that beneficial substances may similarly be removed. Hepcidin, an antimicrobial peptide with pivotal roles in iron homeostasis and pathogen clearance, has biochemical properties amenable to direct removal via CRRT. We hypothesized that serum hepcidin levels would significantly decrease after initiation of CRRT. METHODS: In this prospective, observational trial, we enrolled 13 patients who required CRRT: 11 due to stage 3 AKI, and 2 due to critical illness in the setting of ESKD. Plasma was collected at the time of enrollment, and then plasma and effluent were collected at 10:00 a.m. on the following 3 days. Plasma samples were also collected from healthy controls, and we compared hepcidin concentrations in those with renal disease compared to normal controls, evaluated trends in hepcidin levels over time, and calculated the hepcidin sieving coefficient. RESULTS: Plasma hepcidin levels were significantly higher in patients initiating CRRT than in normal controls (158 ± 60 vs. 17 ± 3 ng/mL respectively, p < 0.001). Hepcidin levels were highest prior to CRRT initiation (158 ± 60 ng/mL), and were significantly lower on day 1 (102 ± 24 ng/mL, p < 0.001) and day 2 (56 ± 14 ng/mL, p < 0.001) before leveling out on day 3 (51 ± 11 ng/mL). The median sieving coefficient was consistent at 0.82-0.83 for each of 3 days. CONCLUSIONS: CRRT initiation is associated with significant decreases in plasma hepcidin levels over the first 2 days of treatment regardless of indication for CRRT, or presence of underlying ESKD. Since reduced hepcidin levels are associated with increased mortality and our data implicate CRRT in hepcidin removal, larger clinical studies evaluating relevant clinical outcomes based on hepcidin trends in this population should be pursued.

Why are we Not Getting More Patients onto Peritoneal Dialysis? Observations From the United States with Global Implications.

Peritoneal dialysis (PD) offers lifestyle advantages over in-center hemodialysis (HD) and is less costly. However, in the United States, less than 12% of end-stage kidney disease (ESKD) patients are maintained on this modality. In this brief review, we discuss some of the factors underlying the low prevalence of PD. These include inadequate patient education, a shortage of sufficiently well-trained medical and nursing personnel, absence of infrastructure to support urgent start PD, and lack of support for assisted PD, among other factors. Understanding and addressing these various issues may help increase the prevalence of PD in the United States and globally.

Association of Incremental peritoneal dialysis with residual kidney function decline in patients on peritoneal dialysis: The balANZ trial.

BACKGROUND: Incremental peritoneal dialysis (PD), defined as less than Full-dose PD prescription, has several possible merits, including better preservation of residual kidney function (RKF), lower peritoneal glucose exposure and reduced risk of peritonitis. The aims of this study were to analyse the association of Incremental and Full-dose PD strategy with RKF and urine volume (UV) decline in patients commencing PD. METHODS: Incident PD patients who participated in the balANZ randomised controlled trial (RCT) (2004-2010) and had at least one post-baseline RKF and UV measurement was included in this study. Patients receiving <56 L/week and ≥56 L/week of PD fluid at PD commencement were classified as Incremental and Full-dose PD, respectively. An alternative cut-point of 42 L/week was used in a sensitivity analysis. The primary and secondary outcomes were changes in measured RKF and daily UV, respectively. RESULTS: The study included 154 patients (mean age 57.9 ± 14.1 years, 44% female, 34% diabetic, mean follow-up 19.5 ± 6.6 months). Incremental and Full-dose PD was commenced by 45 (29.2%) and 109 (70.8%) participants, respectively. RKF declined in the Incremental group from 7.9 ± 3.2 mL/min/1.73 m2 at baseline to 3.2 ± 2.9 mL/min/1.73 m2 at 24 months (p < 0.001), and in the Full-dose PD group from 7.3 ± 2.7 mL/min/1.73 m2 at baseline to 3.4 ± 2.8 mL/min/1.73 m2 at 24 months (p < 0.001). There was no difference in the slope of RKF decline between Incremental and Full-dose PD (p = 0.78). UV declined from 1.81 ± 0.73 L/day at baseline to 0.64 ± 0.63 L/day at 24 months in the Incremental PD group (p < 0.001) and from 1.38 ± 0.61 L/day to 0.71 ± 0.46 L/day in the Full-dose PD group (p < 0.001). There was no difference in the slope of UV decline between Incremental and Full-dose PD (p = 0.18). CONCLUSIONS: Compared with Full-dose PD start, Incremental PD start is associated with similar declines in RKF and UV.

A different PET test: The relationship between pet ownership and peritonitis risk in the Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS).

Pet ownership is common around the world, with pet ownership increasing in many countries. Current guidelines are not supportive of pet ownership for peritoneal dialysis (PD) patients. We examined the association between ownership of cats and dogs and the incidence of peritonitis among PD patients participating in the prospective, observational Peritoneal Dialysis Outcomes and Practice Patterns Study. A total of 3655 PD patients from eight different countries was included, with a median follow-up of 14 months and a total exposure time of 55,475 patient-months. There were 1347 peritonitis episodes with an overall peritonitis rate of 0.29 episodes per patient year. There was no significant increased risk of peritonitis with any type of pet ownership, adjusted hazard ratio (HR) of 1.09 (95% confidence interval (95% CI): 0.96-1.25). However, patients who owned both cats and dogs had an increased risk of peritonitis compared to patients without pets, HR = 1.45 (95% CI: 1.14-1.86). These results suggest that there is no increased risk of peritonitis with pet ownership except for those with both cats and dogs. This information should not prevent PD patients from owning pets but may be helpful for PD patients and their care team to direct training to minimise the risk of peritonitis.

Peritoneal Dialysis-Associated Peritonitis Trends Using Medicare Claims Data, 2013-2017.

RATIONALE & OBJECTIVE: The occurrence and consequences of peritoneal dialysis (PD)-associated peritonitis limit its use in populations with kidney failure. Studies of large clinical populations may enhance our understanding of peritonitis. To facilitate these studies we developed an approach to measuring peritonitis rates using Medicare claims data to characterize peritonitis trends and identify its clinical risk factors. STUDY DESIGN: Retrospective cohort study of PD-associated peritonitis. SETTING & PARTICIPANTS: US Renal Data System standard analysis files were used for claims, eligibility, modality, and demographic information. The sample consisted of patients receiving PD treated at some time between 2013 and 2017 who were covered by Medicare fee-for-service (FFS) insurance with paid claims for dialysis or hospital services. EXPOSURES/PREDICTORS: Peritonitis risk was characterized by year, age, sex, race, ethnicity, vintage of kidney replacement therapy, cause of kidney failure, and prior peritonitis episodes. OUTCOME: The major outcome was peritonitis, identified using ICD-9 and ICD-10 diagnosis codes. Closely spaced peritonitis claims (30 days) were aggregated into 1 peritonitis episode. ANALYTICAL APPROACH: Patient-level risk factors for peritonitis were modeled using Poisson regression. RESULTS: We identified 70,271 peritonitis episodes from 396,289 peritonitis claims. Although various codes were used to record an episode of peritonitis, none was used predominantly. Peritonitis episodes were often identified by multiple aggregated claims, with the mean and median claims per episode being 5.6 and 2, respectively. We found 40% of episodes were exclusively outpatient, 9% exclusively inpatient, and 16% were exclusively based on codes that do not clearly distinguish peritonitis from catheter infections/inflammation ("catheter codes"). The overall peritonitis rate was 0.54 episodes per patient-year (EPPY). The rate was 0.45 EPPY after excluding catheter codes and 0.35 EPPY when limited to episodes that only included claims from nephrologists or dialysis providers. The peritonitis rate declined by 5%/year and varied by patient factors including age (lower rates at higher ages), race (Black > White>Asian), and prior peritonitis episodes (higher rate with each prior episode). LIMITATIONS: Coding heterogeneity indicates a lack of standardization. Episodes based exclusively on catheter codes could represent false positives. Peritonitis episodes were not validated against symptoms or microbiologic data. CONCLUSIONS: PD-associated peritonitis rates decline over time and were lower among older patients. A claims-based approach offers a promising framework for the study of PD-associated peritonitis.

Novel Uses for Peritoneal Dialysis.

Apart from its use in patients with end-stage kidney disease or acute kidney injury, there has recently been interest in the potential use of peritoneal dialysis for other, nonrenal indications. Herein, we review two nonrenal areas that are currently being evaluated: use of liposomal-supported peritoneal dialysis for the removal of endogenous and exogenous toxins and use of peritoneal dialysis to reduce risk of secondary brain injury following ischemic stroke.

Establishing a Core Outcome Measure for Peritoneal Dialysis-related Peritonitis: A Standardized Outcomes in Nephrology-Peritoneal Dialysis Consensus Workshop Report.

Introduction: Peritoneal dialysis (PD)-related peritonitis is one of the leading causes of discontinuation of PD and is considered a critically important outcome for patients on PD. However, there is no universally accepted method of measuring this outcome in clinical trials. Methods: We convened an online consensus workshop to establish a core outcome measure for PD-related peritonitis in clinical trials. Results: A total of 53 participants, including 18 patients and caregivers, from 12 countries engaged in breakout discussions in this workshop. Transcripts were analyzed thematically. We identified the following 3 themes: (i) feasibility and applicability across diverse settings, which reflected the difficulty with implementing laboratory-based measures in resource-limited environments; (ii) ensuring validity, which included minimizing false positives and considering the specificity of symptoms; and (iii) being meaningful and tangible to patients, which meant that the measure should be easy to interpret, reflect the impact that symptoms have on patients, and promote transparency by standardizing the reporting of peritonitis among dialysis units. Conclusion: A core outcome measure for PD-related peritonitis should include both symptom-based and laboratory-based criteria. Thus, the International Society for Peritoneal Dialysis (ISPD) definition of peritonitis is acceptable. However, there should be consideration of reporting suspected peritonitis in cases where laboratory confirmation is not possible. The measure should include all infections from the time of catheter insertion and capture both the rate of infection and the number of patients who remain peritonitis free. A core outcome measure with these features would increase the impact of clinical trials on the care and decision-making of patients receiving PD.

A 6-Month clinical practice pilot study of sucroferric oxyhydroxide on nutritional status in patients on peritoneal dialysis.

BACKGROUND: Hyperphosphatemia is common in patients on peritoneal dialysis (PD). Restricting dietary phosphorus often leads to a decrease in protein intake, which may result in hypoalbuminemia. The high pill burden of phosphate binders may also contribute to compromised appetite and dietary intake. Hypoalbuminemia is associated with an increased risk of morbidity and mortality in PD patients. The goal of this study was to determine if sucroferric oxyhydroxide improves albumin and self-reported measures of appetite in PD patients. METHODS: We performed a prospective, open-label, 6-month, pilot study of 17 adult PD patients from the Denver Metro Area. Patients had to use automated peritoneal dialysis for ≥ 3 months, have a serum albumin ≤ 3.8 g/dL, and have serum phosphate ≥ 5.5 mg/dL or ≤ 5.5 mg/dL on a binder other than SO. SO was titrated to a goal serum phosphate of < 5.5 mg/dL. The primary outcome was change in serum phosphate, albumin, and phosphorus-attuned albumin (defined as albumin divided by phosphorus) over 6 months. RESULTS: The mean (SD) age and dialysis vintage was 55 ± 13 years and 3.8 ± 2.7 years, respectively. Participants' serum phosphate significantly decreased with fewer phosphate binder pills/day after switching to SO. There was no change in serum albumin, appetite, or dietary intake. However, participants had significant improvements in phosphorus-attuned albumin. CONCLUSION: The transition to SO improved phosphorus control, phosphorus-attuned albumin, and pill burden. There were no significant changes in self-reported appetite or dietary intake during the study. These findings suggest that PD patients maintained nutritional status with SO therapy. TRIAL REGISTRATION: First registered at ClinicalTrials.gov ( NCT04046263 ) on 06/08/2019.

ISPD peritonitis guideline recommendations: 2022 update on prevention and treatment.

Peritoneal dialysis (PD)-associated peritonitis is a serious complication of PD and prevention and treatment of such is important in reducing patient morbidity and mortality. The ISPD 2022 updated recommendations have revised and clarified definitions for refractory peritonitis, relapsing peritonitis, peritonitis-associated catheter removal, PD-associated haemodialysis transfer, peritonitis-associated death and peritonitis-associated hospitalisation. New peritonitis categories and outcomes including pre-PD peritonitis, enteric peritonitis, catheter-related peritonitis and medical cure are defined. The new targets recommended for overall peritonitis rate should be no more than 0.40 episodes per year at risk and the percentage of patients free of peritonitis per unit time should be targeted at >80% per year. Revised recommendations regarding management of contamination of PD systems, antibiotic prophylaxis for invasive procedures and PD training and reassessment are included. New recommendations regarding management of modifiable peritonitis risk factors like domestic pets, hypokalaemia and histamine-2 receptor antagonists are highlighted. Updated recommendations regarding empirical antibiotic selection and dosage of antibiotics and also treatment of peritonitis due to specific microorganisms are made with new recommendation regarding adjunctive oral N-acetylcysteine therapy for mitigating aminoglycoside ototoxicity. Areas for future research in prevention and treatment of PD-related peritonitis are suggested.

Peritoneal dialysis adequacy: a paradigm shift.

For the past 30 years, nephrologists have focused on a single minimal threshold of Kt/Vurea to determine the adequacy of peritoneal dialysis (PD). To date, there is no evidence that shows Kt/Vurea to be a good surrogate measure of uremic symptom control or nutritional state in patients on PD. Volume of distribution (Vurea) generally is considered equivalent to total body water (TBW). Yet, accurate determination of TBW is difficult. The most recent International Society for Peritoneal Dialysis practice recommendations on prescribing high-quality PD emphasized incorporation of multiple measures rather than the single value of Kt/Vurea. These measures include shared decision-making between the patient and the care team and assessment of health-related quality of life, burden of uremic symptoms, presence of residual kidney function, volume status, and biochemical measures including serum potassium and bicarbonate levels. In some cases, PD prescriptions can be tailored to the patient priorities and goals of care, such as in frail and pediatric patients. Overall, there has been a paradigm shift in providing high-quality care to PD patients. Instead of focusing on small solute clearance in the form of Kt/Vurea, nephrologists are encouraged to use a more comprehensive assessment of the patient as a whole.

International peritoneal dialysis training practices and the risk of peritonitis.

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

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

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

Prescribing Home Hemodialysis.

Home hemodialysis (HHD), performed more frequently than in-center hemodialysis, is underutilized in the United States but has had a recent resurgence driven predominantly by innovative dialysis equipment that is easy to use, less intrusive to the home, and requires less storage space. There are 3 different hemodialysis machines approved for use in the home but currently NxStage™ accounts for the overwhelming majority of HHD patients. Therefore, it is the focus of this article. To minimize storage space in the home, the NxStage platform minimizes the volume of dialysate that is used per treatment. We refer to this method as the Frequent Low Dialysate Volume Approach (FLDVA). The approach to urea removal with the NxStage platform is much different compared to traditional in-center HD. To minimize the volume of dialysate per treatment, and still achieve target urea removal, the dialysate must be highly saturated. In this article, we explain how to increase the saturation of dialysate fluid. We also draw a parallel between urea removal in peritoneal dialysis and NxStage therapy and use that model to estimate an initial HHD prescription and to alter prescriptions when necessary.

Principles of Kidney Pharmacotherapy for the Nephrologist: Core Curriculum 2021.

Medications are an important part of the management of patients with kidney disease. When used appropriately, pharmacotherapy can slow disease progression and reduce morbidity and mortality. Unfortunately, reduced kidney function can significantly alter the pharmacokinetics and pharmacodynamics of many medications, putting patients at risk for drug toxicity if modifications to therapy are not appropriately managed. Adding complexity to the appropriateness of medication and dosage selection is the difficulty in estimating kidney function and the discordance between the Cockcroft-Gault-derived dosing cut points in most medication package inserts and the estimations of glomerular filtration rate by newer and generally more accurate guideline-recommended equations. This installment of the AJKD Core Curriculum in Nephrology provides recent updates and practical considerations for designing optimal medication regimens. Given the prevalence of abnormal kidney function and its importance in medication selection and dose adjustment, additional focus and specific recommendations are provided for anticoagulant, anti-infective, analgesic, antidiabetic, and antihypertensive agents.