Browsing by Subject "hemodialysis"
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Item 3D simulation of a viscous flow past a compliant model of arteriovenous-graft annastomosis(Elsevier, 2019-03) Bai, Zengding; Zhu, Luoding; Mathematical Sciences, School of ScienceHemodialysis is a common treatment for end-stage renal-disease patients to manage their renal failure while awaiting kidney transplant. Arteriovenous graft (AVG) is a major vascular access for hemodialysis but often fails due to the thrombosis near the vein-graft anastomosis. Almost all of the existing computational studies involving AVG assume that the vein and graft are rigid. As a first step to include vein/graft flexibility, we consider an ideal vein-AVG anastomosis model and apply the lattice Boltzmann-immersed boundary (LB-IB) framework for fluid-structure-interaction. The framework is extended to the case of non-uniform Lagrangian mesh for complex structure. After verification and validation of the numerical method and its implementation, many simulations are performed to simulate a viscous incompressible flow past the anastomosis model under pulsatile flow condition using various levels of vein elasticity. Our simulation results indicate that vein compliance may lessen flow disturbance and a more compliant vein experiences less wall shear stress (WSS).Item Blood pressure in hemodialysis: targets?(Wolters Kluwer, 2017-11) Georgianos, Panagiotis I.; Agarwal, Rajiv; Medicine, School of MedicinePurpose of review In the absence of ‘hard’ clinical-trial evidence to define optimal blood pressure (BP) targets and validate different BP measurement techniques, management of hypertension in hemodialysis is based on expert opinions. In this review, we provide a comparative evaluation of out-of-dialysis BP monitoring versus dialysis-unit BP recordings in diagnosing hypertension, guiding its management and prognosticating mortality risk. Recent findings Owing to their high variability and poor reproducibility, predialysis and postdialysis BP recordings provide inaccurate reflection of the actual BP load outside of dialysis. Contrary to the reverse association of peridialytic BP with mortality, elevated home and ambulatory BP provides a direct mortality signal. Out-of-dialysis BP monitoring, even when done in the clinic, is a reliable approach to manage hypertension in the dialysis unit. Whenever none of these measures are available, median intradialytic SBP can provide a better estimate of interdialytic BP levels compared with peridialytic BP measurements. Summary Although out-of-dialysis BP monitoring have better diagnostic accuracy and prognostic validity, randomized trials are needed to ascertain BP targets for managing hypertension in hemodialysis patients.Item Central Venous Obstruction–Induced Intracranial Hypertension in Hemodialysis Patients: An Underrecognized Cause of Elevated Intracranial Pressure(Wolters Kluwer, 2020-06) Mackay, Devin D.; Takacs, Sara M.; Neurology, School of MedicineBackground: Central venous obstruction (stenosis or occlusion) is common in patients with renal failure on hemodialysis and may be associated with intracranial hypertension (IH). Causes include vein injury from an endoluminal device, lumen obstruction from a device or thrombus, external vein compression, and high venous flow leading to vein intimal hyperplasia. A combination of high venous flow and central venous obstruction can lead to intracranial venous hypertension, impaired cerebrospinal fluid (CSF) resorption, and subsequent IH. Evidence Acquisition: We conducted a search of the English literature using the Ovid MEDLINE Database and PubMed, with a focus on reports involving IH and central venous obstruction in the setting of hemodialysis. We reviewed CSF flow dynamics, the risk factors and causes of central venous obstruction, and the evaluation, management, and outcomes of central venous obstruction-induced IH. Results: Twenty-four cases of IH related to central venous obstruction in hemodialysis patients were identified. Twenty patients had headaches (83.3%) and 9 had visual symptoms (37.5%). The brachiocephalic vein was the most common site of stenosis or occlusion (20/24, 83.3%). Twenty-one patients (87.5%) had resolution of IH with treatment. Two patients died from complications of IH (8.3%). Conclusions: Central venous obstruction–induced IH is likely underrecognized by clinicians and mimics idiopathic IH. Hemodialysis patients with IH should be screened with computed tomography venography of the chest. Optimal treatment is with vascular intervention or a CSF diversion procedure and can help prevent vision loss from papilledema or nervous system damage. Medical management may be appropriate in mild cases or as a bridge to definitive interventional treatment. Increased awareness among clinicians has potential to facilitate the timely diagnosis of this treatable condition with potential for good neurologic and visual outcomes.Item EOS789, a broad-spectrum inhibitor of phosphate transport, is safe with an indication of efficacy in a phase 1b randomized crossover trial in hemodialysis patients(Elsevier, 2020) Hill Gallant, Kathleen M.; Stremke, Elizabeth R.; Trevino, Laurie; Moorthi, Ranjani N.; Doshi, Simit; Wastney, Meryl E.; Hisada, Nozomi; Sato, Jotaro; Ogita, Yoshitaka; Fujii, Naohisa; Matsuda, Yuya; Kake, Takei; Moe, Sharon M.; Medicine, School of MedicineThe treatment of hyperphosphatemia remains challenging in patients receiving hemodialysis. This phase 1b study assessed safety and efficacy of EOS789, a novel pan-inhibitor of phosphate transport (NaPi-2b, PiT-1, PiT-2) on intestinal phosphate absorption in patients receiving intermittent hemodialysis therapy. Two cross-over, randomized order studies of identical design (ten patients each) compared daily EOS789 50 mg to placebo with meals and daily EOS789 100 mg vs EOS789 100 mg plus 1600 mg sevelamer with meals. Patients ate a controlled diet of 900 mg phosphate daily for two weeks and began EOS789 on day four. On day ten, a phosphate absorption testing protocol was performed during the intradialytic period. Intestinal fractional phosphate absorption was determined by kinetic modeling of serum data following oral and intravenous doses of 33Phosphate ( 33P). The results demonstrated no study drug related serious adverse events. Fractional phosphate absorption was 0.53 (95% confidence interval: 0.39,0.67) for placebo vs. 0.49 (0.35,0.63) for 50 mg EOS789; and 0.40 (0.29,0.50) for 100 mg EOS789 vs. 0.36 (0.26,0.47) for 100 mg EOS789 plus 1600 mg sevelamer (all not significantly different). The fractional phosphate absorption trended lower in six patients who completed both studies with EOS789 100 mg compared with placebo. Thus, in this phase 1b study, EOS789 was safe and well tolerated. Importantly, the use of 33P as a sensitive and direct measure of intestinal phosphate absorption allows specific testing of drug efficacy. The effectiveness of EOS789 needs to be evaluated in future phase 2 and phase 3 studies.Item Fluid Resuscitation and Progression to Renal Replacement Therapy in Patients With COVID-19(Elsevier, 2022-02) Holt, Daniel B.; Lardaro, Thomas; Wang, Alfred Z.; Musey, Paul I.; Trigonis, Russell; Bucca, Antonino; Croft, Alexander; Glober, Nancy; Peterson, Kelli; Schaffer, Jason T.; Hunter, Benton R.; Medicine, School of MedicineBackground Coronavirus disease 2019 (COVID-19) is associated with respiratory symptoms and renal effects. Data regarding fluid resuscitation and kidney injury in COVID-19 are lacking, and understanding this relationship is critical. Objectives To determine if there is an association between fluid volume administered in 24 h and development of renal failure in COVID-19 patients. Methods Retrospective chart review; 14 hospitals in Indiana. Included patients were adults admitted between March 11, 2020 and April 13, 2020 with a positive test for severe acute respiratory syndrome coronavirus 2 within 3 days of admission. Patients requiring renal replacement therapy prior to admission were excluded. Volumes and types of resuscitative intravenous fluids in the first 24 h were obtained with demographics, medical history, and other objective data. The primary outcome was initiation of renal replacement therapy. Logistic regression modeling was utilized in creating multivariate models for determining factors associated with the primary outcome. Results The fluid volume received in the first 24 h after hospital admission was associated with initiation of renal replacement therapy in two different multivariate logistic regression models. An odds ratio of 1.42 (95% confidence interval 1.01–1.99) was observed when adjusting for age, heart failure, obesity, creatinine, bicarbonate, and total fluid volume. An odds ratio of 1.45 (95% confidence interval 1.02–2.05) was observed when variables significant in univariate analysis were adjusted for. Conclusions Each liter of intravenous fluid administered to patients with COVID-19 in the first 24 h of presentation was independently associated with an increased risk for initiation of renal replacement therapy, supporting judicious fluid administration in patients with this disease.Item Iron Administration, Infection, and Anemia Management in CKD: Untangling the Effects of Intravenous Iron Therapy on Immunity and Infection Risk(Elsevier, 2020-03-27) Ganz, Tomas; Aronoff, George R.; Gaillard, Carlo A. J. M.; Goodnough, Lawrence T.; Macdougall, Iain C.; Mayer, Gert; Porto, Graça; Winkelmayer, Wolfgang C.; Wish, Jay B.; Medicine, School of Medicinedysfunction, increased exposure to infectious agents, loss of cutaneous barriers, comorbid conditions, and treatment-related factors (eg, hemodialysis and immunosuppressant therapy). Because iron plays a vital role in pathogen reproduction and host immunity, it is biologically plausible that intravenous iron therapy and/or iron deficiency influence infection risk in CKD. Available data from preclinical experiments, observational studies, and randomized controlled trials are summarized to explore the interplay between intravenous iron and infection risk among patients with CKD, particularly those receiving maintenance hemodialysis. The current evidence base, including data from a recent randomized controlled trial, suggests that proactive judicious use of intravenous iron (in a manner that minimizes the accumulation of non–transferrin-bound iron) beneficially replaces iron stores while avoiding a clinically relevant effect on infection risk. In the absence of an urgent clinical need, intravenous iron therapy should be avoided in patients with active infection. Although serum ferritin concentration and transferrin saturation can help guide clinical decision making about intravenous iron therapy, definition of an optimal iron status and its precise determination in individual patients remain clinically challenging in CKD and warrant additional study.Item Long-term Safety of Epoetin Alfa-epbx for the Treatment of Anemia in ESKD: Pooled Analyses of Randomized and Open-label Studies(Elsevier, 2019-08-28) Wish, Jay B.; Rocha, Marcelo G.; Martin, Nancy E.; Reyes, Christian Russel D.; Fishbane, Steven; Smith, Mark T.; Nassar, George; Medicine, School of MedicineRationale & Objective Epoetin alfa-epbx is a biosimilar to the reference product, epoetin alfa. We compare the safety of epoetin alfa-epbx versus epoetin alfa based on a pooled analysis of findings from 2 randomized, double-blind, comparative clinical studies, and report new data for the long-term safety of epoetin alfa-epbx. Study Design Pooled analyses of previously conducted studies. Setting & Participants Hemodialysis patients with anemia. Interventions Data from patients who received 1 or more subcutaneous or intravenous doses of study drug were integrated across route of administration in combined randomized groups (epoetin alfa-epbx, n = 423; epoetin alfa, n = 426). Data from patients who received 1 or more doses of epoetin alfa-epbx in either open-label extension trial were integrated across route of administration in a combined long-term safety studies group (n = 576). Outcomes Adverse events (AEs), immunogenicity, and other outcomes were assessed. Results Incidences of treatment-emergent AEs, serious AEs, and discontinuation of study drug treatment because of treatment-emergent AEs were similar between combined randomized epoetin alfa-epbx and epoetin alfa, which had mean treatment durations of 18.1 and 17.7 weeks, respectively. Incidences of treatment-emergent AEs, serious AEs, and discontinuation of study drug treatment because of treatment-emergent AEs were 86.5%, 39.4%, and 6.6%, respectively, for the combined long-term safety studies group, which had a mean treatment duration of 40.0 weeks. In total, 12 patients across the combined randomized groups (epoetin alfa-epbx, n = 5; epoetin alfa, n = 7) and 9 patients in the combined long-term safety studies group tested anti-recombinant human erythropoietin antibody positive in 1 or more visits during study conduct. No patient in any group developed neutralizing antibodies or pure red blood cell aplasia. Limitations Epoetin alfa comparator not included in the long-term safety studies, greater cumulative exposure to study drug for epoetin alfa-epbx, shorter follow-up in the randomized studies, and potential for selection bias among patients in the open-label long-term safety studies. Conclusions This analysis reinforces previous conclusions of similar safety profiles between epoetin alfa-epbx and epoetin alfa. Furthermore, epoetin alfa-epbx had no unexpected safety signals during long-term treatment.Item Nephrologists Versus Peripherally Inserted Central Catheters: Are the PICCs Winning?(American Society of Nephrology, 2016-08-08) Kalloo, Sean; Wish, Jay B.; Medicine, School of MedicineItem Patiromer Decreases Serum Potassium and Phosphate Levels in Patients on Hemodialysis(Karger, 2016-11) Bushinsky, David A.; Rossignol, Patrick; Spiegel, David M.; Benton, Wade W.; Yuan, Jinwei; Block, Geoffrey A.; Wilcox, Christopher S.; Agarwal, Rajiv; Department of Medicine, IU School of MedicineBackground: Persistent hyperkalemia (serum potassium (K) ≥5.5 mEq/l) is a common condition in hemodialysis (HD) patients, is associated with increased mortality, and treatment options are limited. The effect of patiromer, a gastrointestinal K binder, on serum K was examined in HD patients. Methods: Six hyperkalemic HD patients (5 anuric) were admitted to clinical research units for 15 days (1 pretreatment week and 1 patiromer treatment week) and they received a controlled diet with identical meals on corresponding days of pretreatment and treatment weeks. Phosphate (P) binders were discontinued on admission. Patiromer, 12.6 g daily (divided 4.2 g TID with meals), was started on the Monday morning following the last pretreatment week blood sampling. Serum and 24-hour stool samples were collected daily. Results: Mean ± SE serum K decreased (maximum change per corresponding day, 0.6 ± 0.2 mEq/l, p = 0.009) and fecal K increased 58% on patiromer compared with the pretreatment week. During the pretreatment week, 69.0, 47.6, and 11.9% of patients' serum K values were ≥5.5, ≥6.0, and ≥6.5 mEq/l, respectively. This was reduced to 38.1% (p = 0.009), 11.9% (p < 0.001), and 2.4% (p = 0.2) on patiromer. Following P binder discontinuation, the long interdialytic interval mean ± SE serum P numerically increased from 5.8 ± 0.4 to 7.0 ± 0.5 mg/dl (p = 0.06). On patiromer, P decreased from 7.0 ± 0.5 to 6.2 ± 0.5 mg/dl (p = 0.04). While on patiromer, fecal P numerically increased by 112 ± 72 mg/day (17%; p = 0.1792; range -148 to 344 mg/day). No patient discontinued patiromer because of adverse events (AEs); none had serious AEs. Conclusions: In 6 hyperkalemic HD patients, patiromer decreased serum K and P levels and increased fecal K.Item Percutaneous arteriovenous fistula creation with the 4F WavelinQ EndoAVF System(Elsevier, 2022-03) Berland, Todd; Clement, Jason; Inston, Nicholas; Kreienberg, Paul; Ouriel, Kenneth; Surgery, School of MedicineBackground Percutaneous devices for creation of native arteriovenous fistulae offer an alternative to traditional open surgical techniques. The 4F WavelinQ EndoAVF System was developed as a lower profile alternative to facilitate access through smaller vessels and minimize access site complications; The current report is the original first experience of this device, assessing outcome in 120 patients followed for 6 months. Methods The use of the 4F WavelinQ system in three studies, EASE (32 patients), EASE-2 (24 patients), and the EU postmarket clinical follow-up study (64 patients) was aggregated and analyzed. Patients were followed with duplex ultrasound at discharge and follow-up visits at 1, 3, and 6 months. Primary, assisted primary, and secondary patency rates were evaluated as Kaplan-Meier estimates and standard errors. Time to maturity and time to successful cannulation were defined as the mean ± standard deviation days from the procedure in patients enrolled on dialysis. Results Procedural success was achieved in 116 patients (96.7%). Primary, assisted-primary, and secondary 6-month patency rates were 71.9% ± 4.5%, 80.7% ± 4.1%, and 87.8% ± 3.3%, respectively. Time to maturity averaged 41 ± 17 days. Time to successful cannulation averaged 68 ± 51 days. Device-related serious adverse events were reported in 3 of 120 patients (2.5%) and procedure-related serious adverse events occurred in 7 of 120 patients (5.8%). Arterial or venous access complications were not reported in any of the patients. Access circuit reinterventions were performed in 23 patients (19.2%), split between those performed for EndoAVF maturation (13/120 [10.8%]) and maintenance (11/120 [9.2%]). Conclusions Percutaneous creation of native dialysis fistulae with the 4F WavelinQ EndoAVF System is safe and effective, with favorable durability and a low rate of serious complications and reinterventions through 6-month follow-up. Use of the 4F device allows for percutaneous fistula creation between the radial artery and radial vein or the ulnar artery and ulnar vein. These findings suggest that the 4F device is a useful percutaneous alternative to open surgical AVF or endovascular AVF with larger bore devices.