Journal of clinical monitoring and computing
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J Clin Monit Comput · Feb 1999
Evaluation of a new advanced thoracic bioimpedance device for estimation of cardiac output.
This study is an evaluation of a new thoracic bioimpedance cardiac output monitoring system which incorporates a modified form of the Kubicek equation and a method of estimating the left ventricular ejection time from the time derivative bioimpedance signals. ⋯ The results from the porcine study show that the new system performed well over a wide range of cardiac outputs, comparing favorably with data from other new bioimpedance cardiac output devices currently available in the market.
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J Clin Monit Comput · Feb 1999
Work of breathing-tidal volume relationship: analysis on an in vitro model and clinical implications.
Work of breathing (WoB) is currently employed to assess the afterload on the respiratory muscles and to estimate the energy expenditure for breathing. Since WoB depends on the ventilated tidal volume (TV), WoB*L(-1), the indicized form of WoB has been employed as a measure of WoB which is independent of TV. Actually, the independence of WoB*L(-1) from the ventilated TV has never been demonstrated. The aim of this study was to verify the predicted TV-independence of WoB*L(-1) on an in vitro model. ⋯ These results demonstrate the TV-dependence of WoB*L(-1) and suggest that WoB*L(-1), if TV changes, cannot be considered as an index of respiratory muscle afterload and should not be used as a guide for weaning patients from the mechanical ventilation. Finally, we introduced a new parameter (WoB1L) which seems to be a more TV-independent measure of respiratory work.
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J Clin Monit Comput · Feb 1999
Case ReportsEvaluation of hemostasis by the Clot Signature Analyzer: a potentially valuable device for the anesthesiologist.
Rapid detection of hemostatic defects presents a challenge for the anesthesiologist who must balance anesthetic and surgical considerations for maintaining adequate platelet and coagulant factors, while keeping allogenic blood exposure to a minimum. The Clot Signature Analyzer, a point-of-care device capable of rapid response and easy interpretation is described here. Its applicability in two obstetrical patients with platelet dysfunction is discussed.