8 results on '"Fissell WH"'
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2. Renal Replacement Therapy in the ICU: The Collateral of Habit.
- Author
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Siew ED and Fissell WH
- Subjects
- Habits, Humans, Intensive Care Units, Renal Replacement Therapy, Acute Kidney Injury therapy, Respiration, Artificial
- Published
- 2020
- Full Text
- View/download PDF
3. Beta-lactam carryover in arterial and central venous catheters is negligible.
- Author
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Marsh E, Verhoven SM, Groszek JJ, Fissell WH, An G, Patel P, Creech B, and Shotwell M
- Subjects
- Animals, Cattle, Chromatography, High Pressure Liquid, Catheters, Indwelling, Cefepime blood, Central Venous Catheters, Meropenem blood, Piperacillin blood, Vancomycin blood
- Abstract
Background: Therapeutic drug monitoring is used for aminoglycosides and vancomycin, and has been proposed for β-lactam antibiotics. Clinical blood samples in the ICU are often obtained via an existing vascular catheter rather than fresh needle phlebotomy. If antibiotics had previously been infused through a vascular catheter then used for blood sampling, carryover of antibiotic from the infusion to the sample might result in misleading assessments of target attainment. To address this concern we conducted a series of in vitro measurements of carryover for three commonly used antibiotics., Methods: We infused piperacillin-tazobactam, meropenem, and cefepime at pharmacologic concentrations through commonly used vascular catheters at our hospital and flushed the catheters. We then aspirated warmed citrated bovine blood through each catheter and measured antibiotic concentrations in each aspirate., Results: Carryover was below the limits of detection for piperacillin-tazobactam, meropenem, and vancomycin. Cefepime carryover, in contrast, was not negligible and needs to be investigated more fully., Conclusion: Carryover from prior infusions does not appear to jeopardize measurements of piperacillin-tazobactam, meropenem, or vancomycin in commonly used vascular catheters at our institution. Caution in interpreting samples obtained for cefepime measurements appears advised until more data is available., (Copyright © 2018. Published by Elsevier B.V.)
- Published
- 2018
- Full Text
- View/download PDF
4. Therapeutic drug monitoring of piperacillin and tazobactam by RP-HPLC of residual blood specimens.
- Author
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Verhoven SM, Groszek JJ, Fissell WH, Seegmiller A, Colby J, Patel P, Verstraete A, and Shotwell M
- Subjects
- Blood Specimen Collection, Chromatography, Reverse-Phase, Drug Monitoring economics, Humans, Penicillanic Acid analysis, Penicillanic Acid pharmacokinetics, Piperacillin pharmacokinetics, Piperacillin, Tazobactam Drug Combination, Sepsis drug therapy, Tazobactam, Chromatography, High Pressure Liquid methods, Drug Monitoring methods, Penicillanic Acid analogs & derivatives, Piperacillin analysis
- Abstract
Background: Sepsis is a common diagnosis in critical care with inpatient mortality rates up to 50%. Sepsis care is organized around source control, antibiotics, and supportive care. Drug disposition is deranged by changes in volume of distribution and regional blood flow, as well as multiple organ failure. Thus, assuring that each patient with sepsis attains pharmacokinetic targets is challenging. There is currently no commercially available FDA-approved assay to measure piperacillin-tazobactam, very commonly used as a beta-lactam/beta-lactamase inhibitor combination antibiotic in the intensive care unit (ICU)., Methods: Samples were prepared by ultrafiltration of plasma collected in lithium heparin Vacutainers. Separation was achieved by gradient elution on a C-18 column followed by UV detection at 214 nm. The method is validated in residual blood samples allowing investigators to exploit a waste product to develop insight into beta-lactam pharmacokinetics in the ICU., Results: Accuracy and precision were within the 25% CLIA error standard for other antibiotic assays. Free piperacillin concentrations were also in good agreement with total piperacillin concentrations measured in the same plasma by an assay in clinical use outside the United States., Conclusion: We describe a method for measuring piperacillin and tazobactam that meets clinical validation standards. Quick turnaround time and excellent accuracy on a low-cost platform make this method more than adequate for use as a routine therapeutic drug monitoring tool., (Copyright © 2018 Elsevier B.V. All rights reserved.)
- Published
- 2018
- Full Text
- View/download PDF
5. The bridge between transplantation and regenerative medicine: Beginning a new Banff classification of tissue engineering pathology.
- Author
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Solez K, Fung KC, Saliba KA, Sheldon VLC, Petrosyan A, Perin L, Burdick JF, Fissell WH, Demetris AJ, and Cornell LD
- Subjects
- Graft Rejection classification, Humans, Graft Rejection pathology, Kidney pathology, Kidney Transplantation, Pathology, Clinical standards, Regenerative Medicine, Tissue Engineering
- Abstract
The science of regenerative medicine is arguably older than transplantation-the first major textbook was published in 1901-and a major regenerative medicine meeting took place in 1988, three years before the first Banff transplant pathology meeting. However, the subject of regenerative medicine/tissue engineering pathology has never received focused attention. Defining and classifying tissue engineering pathology is long overdue. In the next decades, the field of transplantation will enlarge at least tenfold, through a hybrid of tissue engineering combined with existing approaches to lessening the organ shortage. Gradually, transplantation pathologists will become tissue-(re-) engineering pathologists with enhanced skill sets to address concerns involving the use of bioengineered organs. We outline ways of categorizing abnormalities in tissue-engineered organs through traditional light microscopy or other modalities including biomarkers. We propose creating a new Banff classification of tissue engineering pathology to standardize and assess de novo bioengineered solid organs transplantable success in vivo. We recommend constructing a framework for a classification of tissue engineering pathology now with interdisciplinary consensus discussions to further develop and finalize the classification at future Banff Transplant Pathology meetings, in collaboration with the human cell atlas project. A possible nosology of pathologic abnormalities in tissue-engineered organs is suggested., (© 2017 The Authors. American Journal of Transplantation published by Wiley Periodicals, Inc. on behalf of The American Society of Transplantation and the American Society of Transplant Surgeons.)
- Published
- 2018
- Full Text
- View/download PDF
6. Achieving more frequent and longer dialysis for the majority: wearable dialysis and implantable artificial kidney devices.
- Author
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Fissell WH, Roy S, and Davenport A
- Subjects
- Equipment Design, Humans, Kidney Failure, Chronic diagnosis, Kidney Failure, Chronic physiopathology, Miniaturization, Quality of Life, Time Factors, Treatment Outcome, Kidney physiopathology, Kidney Failure, Chronic therapy, Kidneys, Artificial, Peritoneal Dialysis, Continuous Ambulatory instrumentation, Renal Dialysis instrumentation
- Abstract
The long-term survival for many chronic kidney failure patients who remain treated by dialysis in economically advanced countries remains similar to that of those with solid-organ malignancy, despite a disproportionate amount of health-care expenditure. As such, the current paradigm of three times weekly in-center hemodialysis for 4 h or shorter sessions needs to change to improve patient outcomes. Although more frequent and longer dialysis sessions have been reported to improve cardiovascular risk surrogates and short-term outcomes, these options are only practically available to a very small fraction of the total dialysis population. As such, radically new approaches are required to improve patient outcomes and quality of life for the majority of dialysis patients. Currently, two different approaches are being developed, wearable devices based on current dialysis techniques and more futuristic implantable devices modeled on the natural nephron.
- Published
- 2013
- Full Text
- View/download PDF
7. Development of continuous implantable renal replacement: past and future.
- Author
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Fissell WH, Fleischman AJ, Humes HD, and Roy S
- Subjects
- Biocompatible Materials chemistry, Cell Culture Techniques, Dialysis Solutions, Equipment Design, Forecasting, Hemofiltration, Humans, Kidney Failure, Chronic diagnosis, Kidney Failure, Chronic mortality, Kidney Tubules cytology, Kidney Tubules growth & development, Kidneys, Artificial, Materials Testing methods, Membranes, Artificial, Nanotechnology trends, Renal Replacement Therapy instrumentation, Renal Replacement Therapy methods, Silicon chemistry, United States, Uremia, Kidney Failure, Chronic therapy, Prostheses and Implants, Renal Dialysis instrumentation, Renal Dialysis trends, Renal Replacement Therapy trends
- Abstract
Most of the 400,000+ patients in the United States with kidney failure depend on dialysis treatments in dedicated dialysis centers for 3 h to 5 h, usually 3 times a week, but they still suffer from accelerated cardiovascular disease and infections. Extended daily dialysis, for 6 to 8 hours every day, seems to be associated with better outcomes but would overwhelm the dialysis networks and severely limit patient activity. Technology to miniaturize and automate home dialysis will be necessary to offer extended daily dialysis to most dialysis patients. Miniaturization of existing hollow-fiber polymer membranes is constrained by requirements for high driving pressures for circulation and convective clearance. Recent advances in membrane technology based on microelectromechanical systems (MEMS) promise to enable the development of continuous implantable renal replacement therapy. Silicon nanoporous membranes with a highly monodisperse pore size distribution have been produced using protocols amenable to low-cost batch fabrication similar to those used to produce microelectronics. Hydraulic permeability of the flat-sheet membranes with critical pore sizes in the range of 8-100 nm has been measured to confirm that conventional fluid transport models are sufficiently accurate for predictive design for bulk liquid flow in an implantable hemofilter. Membrane biocompatibility was tested in vitro with human proximal tubule cells and revealed that silicon does not exhibit cytotoxicity, as evidenced by the formation of confluent cell layers with tight junctions and central cilia. Filtration characterization demonstrated that the nanoporous membranes exhibit size-dependent solute rejection in agreement with steric hindrance models. These advances in membrane technology are fundamentally enabling for a paradigm shift from an in-center to implantable dialysis system.
- Published
- 2007
- Full Text
- View/download PDF
8. The future of hemodialysis membranes.
- Author
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Humes HD, Fissell WH, and Tiranathanagul K
- Subjects
- Equipment Design, Humans, Membranes, Artificial, Permeability, Renal Dialysis adverse effects, Silicon, Static Electricity, Ultrafiltration methods, Renal Dialysis instrumentation, Renal Dialysis trends
- Abstract
Hemodialytic treatment of patients with either acute or chronic renal failure has had a dramatic impact on the mortality rates of these patients. Unfortunately, this membrane-based therapy is still incomplete renal replacement, as the mortality and morbidity of these patients remain unacceptably high. Much progress must be made to improve the biocompatibility of hemodialysis membranes as well as their hydraulic and permselective properties to remove small solutes and 'middle molecules' in compact cartridges. The next directions of development will leverage materials and mechanical engineering technology, including microfluidics and nanofabrication, to further improve the clearance functions of the kidney to replicate glomerular permselectivity while retaining high rates of hydraulic permeability. The extension of membrane technology to biohybrid devices utilizing progenitor/stem cells will be another substantive advance for renal replacement therapy. The ability to not only replace solute and water clearance but also active reabsorptive transport and metabolic activity will add additional benefit to the therapy of patients suffering from renal failure. This area of translational research is rich in creative opportunities to improve the unmet medical needs of patients with either chronic or acute renal failure.
- Published
- 2006
- Full Text
- View/download PDF
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