Journal of clinical monitoring and computing
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J Clin Monit Comput · May 1999
Comparative StudyTranscranial Doppler monitoring compared with invasive monitoring of intracranial pressure during acute intracranial hypertension.
To determine whether a simple transcanial Doppler waveform variable-pulsatility difference (systolic - diastolic blood flow velocity) can serve as a measure of critical changes in cerebral perfusion. ⋯ In pigs with induced diffuse intracranial hypertension, noninvasive transcranial Doppler waveform monitoring of pulsatility difference can identify increased cerebral oxygen extraction and dangerously decreased cerebral perfusion pressure.
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J Clin Monit Comput · May 1999
Randomized Controlled Trial Comparative Study Clinical TrialOn the dynamic performance of the Abbott Safeset blood-conserving arterial line system.
Critically ill patients frequently have indwelling arterial lines placed during their Intensive Care Unit stay. The lines are used to monitor blood pressure continuously, administer drugs and to draw blood for a variety of physiologic tests. Several blood-conserving arterial line systems have been developed to eliminate the need to discard blood in the process of obtaining undiluted and uncontaminated blood samples. The purpose of this study was to evaluate the dynamic performance of one such system the Abbott Clinical Care System Safeset blood conserving arterial line system - in comparison to a conventional arterial line system. ⋯ Because the Abbott Safeset blood-conserving arterial line system is underdamped and has a lower resonant frequency compared to the traditional arterial system, it may overestimate systolic blood pressure, particularly in patients with high heart rates.
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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
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
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%.