Journal of clinical monitoring and computing
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J Clin Monit Comput · Dec 2017
Influence of continuously evolving transcatheter aortic valve implantation technology on cerebral oxygenation.
This study assessed the influence of the evolution in Transcatheter Aortic Valve Implantation technology on cerebral oxygenation. Cerebral oxygenation was measured continuously with Near-Infrared Spectroscopy and compared retrospectively between balloon-expandable, self-expandable and differential deployment valves which were implanted in 12 (34%), 17 (49%) and 6 patients (17%), respectively. Left and right SctO2 values were averaged at four time points and used for analysis (i.e. at baseline, balloon-aortic valvuloplasty, valve deployment, and at the end of the procedure). ⋯ Furthermore, both the incidence and duration below a cerebral oxygenation of 55% was significantly different between balloon and self-expandable valves (p = 0.038 and p = 0.018, respectively). This study demonstrated that Transcatheter Aortic Valve Implantation procedures are associated with significant cerebral desaturations, especially during balloon-aortic valvuloplasty and valve deployment. Moreover, our results showed that latest innovations in Transcatheter Aortic Valve Implantation technology beneficially influenced the adequacy of cerebral perfusion.
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J Clin Monit Comput · Dec 2017
A feasability study of color flow doppler vectorization for automated blood flow monitoring.
An ongoing issue in vascular medicine is the measure of the blood flow. Catheterization remains the gold standard measurement method, although non-invasive techniques are an area of intense research. We hereby present a computational method for real-time measurement of the blood flow from color flow Doppler data, with a focus on simplicity and monitoring instead of diagnostics. ⋯ Errors on synthetic images ranged from nonexistent to substantial depending on experimental conditions. Mean errors on measurements from our phantom flow simulation ranged from 1.2 to 40.2% for angle estimation, and from 3.2 to 25.3% for real-time flow estimation. This study is a proof of concept showing that accurate measurement can be done from automated color flow Doppler signal extraction, providing the industry the opportunity for further optimization using raw ultrasound data.
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J Clin Monit Comput · Dec 2017
The influence of PEEP and positioning on central venous pressure and venous hepatic hemodynamics in patients undergoing liver resection.
In order to assess the occurrence of blood congestion in the liver during liver resection, we aimed to evaluate the influence of a positive-end-expiratory-pressure (PEEP) and positioning of patients on central venous pressure (CVP) and venous hepatic blood flow parameters. We further analyzed correlations between CVP and venous hepatic blood flow parameters. ⋯ Changes of central venous pressure due to changes of PEEP and positioning were not correlated with changes of venous hepatic blood flow parameters as measured after equilibration. Strategies aiming for low central venous pressure cannot be supported by these results. However, before ruling out low-CVP-strategies during liver resections these results should be confirmed by further studies.
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J Clin Monit Comput · Dec 2017
Observational StudyApplicability of stroke volume variation in patients of a general intensive care unit: a longitudinal observational study.
Sinus rhythm (SR) and controlled mechanical ventilation (CV) are mandatory for the applicability of respiratory changes of the arterial curve such as stroke volume variation (SVV) to predict fluid-responsiveness. Furthermore, several secondary limitations including tidal volumes <8 mL/kg and SVV-values within the "gray zone" of 9-13% impair prediction of fluid-responsiveness by SVV. Therefore, we investigated the prevalence of these four conditions in general ICU-patients. ⋯ In 9.7% (27/278) of the first measurements and in 12.8% (615/4801) of all measurements the patients did neither have SR nor CV. Only 20 of 278 (7.2%) of the first measurements and 8.2% of all measurements fulfilled both major criteria (CV, SR) and both minor criteria for the applicability of SVV. The applicability of SVV in ICU-patients is limited due to the absence of mandatory criteria during the majority of measurements.