Journal of clinical monitoring and computing
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J Clin Monit Comput · May 1999
Inter observer variability of the transcranial Doppler ultrasound technique: impact of lack of practice on the accuracy of measurement.
Published data on the observer variability with the transcranial doppler (TCD) ultrasound are limited by the use of the product moment correlation coefficient. This study was designed to quantify the intra and inter observer variability with the TCD in terms of the intra class correlation coefficient (ICC) and to assess the impact of lack of practice on the observer variability and the accuracy of data generated. ⋯ A high level of observer agreement is possible with the TCD for measurement of cerebral blood flow velocities. Lack of regular practice with the system reduces the accuracy of measurements and impacts on both measured and calculated indices.
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To design and evaluate a clinical monitor of respiratory drive (P0.1) and other respiratory variables in a simple way, using a commercial ventilator. ⋯ At rest, the ventilator introduced a minor influence on inspiratory time and P0.1, but not in ventilation, tidal volume, expiratory duration and respiratory frequency. During exercise, the influence was more evident. This effect could also be noticed in the coefficients of variation. The responses to mechanical loads were easily recorded and can be used as a simple test of central load-compensating mechanisms. CONCLUSIONS. The ventilator, with limitations, may be an alternative to conventional techniques, especially in clinical studies of the central inspiratory activity with and without respiratory loading.
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J Clin Monit Comput · May 1999
Point-of-care and standard laboratory coagulation testing during cardiovascular surgery: balancing reliability and timeliness.
The use of point-of-care technology has increased faster than efforts to validate its effectiveness compared to standard laboratory testing modalities. To address this issue with a current point-of-care coagulation system (HEMOCHRON Jr, International Technidyne Corporation (ITC), Edison, NJ), we designed a study to test the hypothesis that data obtained from point-of-care coagulation equipment correlates with data obtained from standard laboratory coagulation equipment. One of the potential advantages gained using point-of-care testing is the ability to obtain more rapid results. To address this issue, turnaround time, defined as the elapsed time (in minutes) from when the sample was acquired from the patient until the investigators knew the results, was also determined. ⋯ The results from this study population reveal that data obtained from point-of-care prothrombin time, international normalized ratio and activated partial thromboplastin time results correlate with results obtained from standard laboratory coagulation testing. The value of obtaining reliable results in a timely fashion offers a potential advantage for point-of-care testing in dinical situations, such as in the operating room, where saving time may translate into financial savings.
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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
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.