Journal of clinical monitoring and computing
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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.
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J Clin Monit Comput · Feb 1999
Clinical TrialThe calibration and validation of a phase-modulated near-infrared cerebral oximeter.
This study was undertaken to compare the cerebral oxygenation measured by an experimental phase-modulated near-infrared (NIR) spectroscopy system with capillary saturation estimated from jugular venous oxygen saturation. ⋯ Under the conditions tested, an experimental phase-modulated near-infrared spectroscopy system calibrated using an optical bench agreed with capillary saturation estimated from jugular venous samples. Further work is necessary to demonstrate valid performance of the system under other conditions.
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J Clin Monit Comput · Feb 1999
Optimization of alarms: a study on alarm limits, alarm sounds, and false alarms, intended to reduce annoyance.
Alarms in the operating room remain a major source of annoyance and confusion. Nearly all alarms result from a transgression of certain alarm limits. We surveyed manufacturers at a major meeting of anesthesiologists for their default alarm limits. ⋯ The leading reason for turning off alarms was the large number of false alarms. Estimates of the number of false alarms varied from 30% to 76%. The desired role of alarms in anesthetic practice and some suggestions for the general improvement of alarms are discussed.
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J Clin Monit Comput · Feb 1999
Meta Analysis Comparative StudyA meta-analysis of studies using bias and precision statistics to compare cardiac output measurement techniques.
Bias and precision statistics have succeeded regression analysis when measurement techniques are compared. However, when applied to cardiac output measurements, inconsistencies occur in reporting the results of this form of analysis. ⋯ When using bias and precision statistics, cardiac output, bias, limits of agreement, and percentage error should be presented. Using current reference methods, acceptance of a new technique should rely on limits of agreement of up to +/-30%.
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J Clin Monit Comput · Feb 1999
Randomized Controlled Trial Clinical TrialThe effect of maintaining a constant preload or a constant degree of thumb abduction in the isometric twitch force of the thumb.
To investigate the effects of maintaining a constant preload and of maintaining a constant degree of thumb abduction on the isometric twitch force during mechanomyography of the thumb, we monitored neuromuscular function in patients anaesthetized without the use of a neuromuscular blocking agent. In addition, we studied the relationship between the degree of thumb abduction, twitch force and preload. ⋯ Changes in length of the contracting muscle fibres and creep phenomena in the connective tissue of the muscles, both leading to changes in the sarcomere length of the muscle fibres, may explain the observations in this study. In general, a stabilized preload at a constant degree of abduction seems to be required in order to obtain a stable twitch force.