Efficacy of Combination of N-acetylcysteine, Gentamicin, and Amphotericin B for Prevention of Microbial Colonization of Ventricular Assist Devices

We assessed the in vitro antimicrobial activity and the in vivo efficacy of dipping ventricular assist devices in a combination of N-acetylcysteine, gentamicin, and amphotericin B (NAC/G/A). Ventricular assist devices dipped in NAC/G/A exhibited broad-spectrum antimicrobial activity in vitro and were less likely than undipped devices to become colonized with Staphylococcus aureus in a rabbit model.

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Response of a physiological controller for ventricular assist devices during acute patho-physiological events: an in vitro study

Biomedical Engineering / Biomedizinische Technik ◽

10.1515/bmt-2016-0155 ◽

2017 ◽

Vol 62 (6) ◽

pp. 623-633 ◽

Cited By ~ 2

Author(s):

Anastasios Petrou ◽

Panagiotis Pergantis ◽

Gregor Ochsner ◽

Raffael Amacher ◽

Thomas Krabatsch ◽

...

Keyword(s):

Valsalva Maneuver ◽

Constant Speed ◽

Ventricular Assist Devices ◽

Moving Window ◽

Clinical Implementation ◽

Premature Ventricular Contractions ◽

Ventricular Assist ◽

Assist Devices ◽

Mock Circulation

AbstractThe current paper analyzes the performance of a physiological controller for turbodynamic ventricular assist devices (tVADs) during acute patho-physiological events. The numerical model of the human blood circulation implemented on our hybrid mock circulation was extended in order to simulate the Valsalva maneuver (VM) and premature ventricular contractions (PVCs). The performance of an end-diastolic volume (EDV)-based physiological controller for VADs, named preload responsive speed (PRS) controller was evaluated under VM and PVCs. A slow and a fast response of the PRS controller were implemented by using a 3 s moving window, and a beat-to-beat method, respectively, to extract the EDV index. The hemodynamics of a pathological circulation, assisted by a tVAD controlled by the PRS controller were analyzed and compared with a constant speed support case. The results show that the PRS controller prevented suction during the VM with both methods, while with constant speed, this was not the case. On the other hand, the pump flow reduction with the PRS controller led to low aortic pressure, while it remained physiological with the constant speed control. Pump backflow was increased when the moving window was used but it avoided sudden undesirable speed changes, which occurred during PVCs with the beat-to-beat method. In a possible clinical implementation of any physiological controller, the desired performance during frequent clinical acute scenarios should be considered.

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In vitro comparison of the hemocompatibility of two centrifugal left ventricular assist devices

Journal of Thoracic and Cardiovascular Surgery ◽

10.1016/j.jtcvs.2018.07.085 ◽

2019 ◽

Vol 157 (2) ◽

pp. 591-599.e4 ◽

Cited By ~ 9

Author(s):

Rashad Zayat ◽

Ajay Moza ◽

Oliver Grottke ◽

Tim Grzanna ◽

Tamara Fechter ◽

...

Keyword(s):

Left Ventricular ◽

Ventricular Assist Devices ◽

Left Ventricular Assist Devices ◽

Ventricular Assist ◽

Assist Devices ◽

Left Ventricular Assist ◽

In Vitro Comparison

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In vitro evaluation of a new resilient, hard-carbon, thin-film coating as a bearing material for ventricular assist devices ——In Vitro Bearing Evaluation of BioMedFlex

Journal of Biomedical Science and Engineering ◽

10.4236/jbise.2010.35073 ◽

2010 ◽

Vol 03 (05) ◽

pp. 525-528 ◽

Cited By ~ 2

Author(s):

Nicole A. Mielke ◽

Alex L. Massiello ◽

David J. Horvath ◽

Stephen M. Benefit ◽

Darren Burgess ◽

...

Keyword(s):

Thin Film ◽

Film Coating ◽

Ventricular Assist Devices ◽

Hard Carbon ◽

Thin Film Coating ◽

Bearing Material ◽

Ventricular Assist ◽

In Vitro Evaluation ◽

Assist Devices

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Impact of the Order of Initiation of Fluconazole and Amphotericin B in Sequential or Combination Therapy on Killing of Candida albicans In Vitro and in a Rabbit Model of Endocarditis and Pyelonephritis

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.45.2.485-494.2001 ◽

2001 ◽

Vol 45 (2) ◽

pp. 485-494 ◽

Cited By ~ 40

Author(s):

Arnold Louie ◽

Pamela Kaw ◽

Partha Banerjee ◽

Weiguo Liu ◽

George Chen ◽

...

Keyword(s):

Candida Albicans ◽

Amphotericin B ◽

Induced Resistance ◽

Rabbit Model ◽

In Vivo Studies ◽

Infection Model ◽

Simultaneous Exposure ◽

The Impact

ABSTRACT In vitro time-kill studies and a rabbit model of endocarditis and pyelonephritis were used to define the impact that the order of exposure of Candida albicans to fluconazole (FLC) and amphotericin B (AMB), as sequential and combination therapies, had on the susceptibility of C. albicans to AMB and on the outcome. The contribution of FLC-induced resistance to AMB for C. albicans also was assessed. In vitro, AMB monotherapy rapidly killed each of four C. albicans strains; FLC alone was fungistatic. Preincubation of these fungi with FLC for 18 h prior to exposure to AMB decreased their susceptibilities to AMB for 8 to >40 h. Induced resistance to AMB was transient, but the duration of resistance increased with the length of FLC preincubation. Yeast sequentially incubated with FLC followed by AMB plus FLC (FLC→AMB+FLC) showed fungistatic growth kinetics similar to that of fungi that were exposed to FLC alone. This antagonistic effect persisted for at least 24 h. Simultaneous exposure of C. albicans to AMB and FLC [AMB+FLC(simult)] demonstrated activity similar to that with AMB alone for AMB concentrations of ≥1 μg/ml; antagonism was seen using an AMB concentration of 0.5 μg/ml. The in vitro findings accurately predicted outcomes in our rabbit infection model. In vivo, AMB monotherapy and treatment with AMB for 24 h followed by AMB plus FLC (AMB→AMB+FLC) rapidly sterilized kidneys and cardiac vegetations. AMB+FLC(simult) and FLC→AMB treatments were slower in clearing fungi from infected tissues. FLC monotherapy and FLC→AMB+FLC were both fungistatic and were the least active regimens. No adverse interaction was observed between AMB and FLC for the AMB→FLC regimen. However, FLC→AMB treatment was slower than AMB alone in clearing fungi from tissues. Thus, our in vitro and in vivo studies both demonstrate that preexposure of C. albicans to FLC reduces fungal susceptibility to AMB. The length of FLC preexposure and whether AMB is subsequently used alone or in combination with FLC determine the duration of induced resistance to AMB.

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