Journal of clinical monitoring and computing
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J Clin Monit Comput · Jul 1998
Sensitivity of near infrared spectroscopy to cerebral and extra-cerebral oxygenation changes is determined by emitter-detector separation.
To examine the effect of two emitter-detector separations (2.7 and 5.5 cm) on the detection of changes in cerebral and extra-cerebral tissue oxygenation using near infrared spectroscopy (NIRS). ⋯ The differing sensitivity of the proximal and distal channels to changes in cerebral and extracerebral oxygenation is compatible with theoretical models of NIR light transmission in the adult head and may provide a basis for spatially resolving these changes. The optimal emitter-detector separation for adult NIRS requires further investigation and may differ between individuals.
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J Clin Monit Comput · Jul 1998
Sampling intervals to record severe hypotensive and hypoxic episodes in anesthetised patients.
To define the longest sampling interval which will faithfully record the time course of episodes of severe hypotension and hypoxia in anesthetised patients. ⋯ Our current anesthetic record is inadequate to record many of the severe changes that we observed. One minute recording intervals, such as used in many electronic record keeping systems, are too slow to capture the rapid rates of change seen, and may lead to the assumption that an episode was not recognized promptly or that treatment was not administered in a timely manner.
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J Clin Monit Comput · Jul 1998
Evaluation in volunteers of the VIA V-ABG automated bedside blood gas, chemistry, and hematocrit monitor.
To evaluate the VIA V-ABG (VIA Medical Corp.) point-of-care blood gas and chemistry monitor in healthy human volunteers, with particular emphasis on the measurement of blood gases. ⋯ Over the range of blood gas values assessed, blood gas measurements by the VIA V-ABG device were clinically acceptable and met minimal performance criteria utilizing current Medicare CLIA proficiency standards. Performance criteria were also met by the VIA V-ABG device for Na, K, and Hct measurements but the range of values was too narrow to allow characterization of clinical acceptability. The VIA V-ABG device appears to perform well compared with the results which have been published for other point-of-care devices. Comparison between different studies investigating point-of-care devices is difficult due to several factors (range of values measured, comparison device, population studied, etc.). Some of these instruments, including the VIA V-ABG device, may serve quite well as point-of-care devices to perform certain tests at the bedside. Whether or not any of these devices can substitute for traditional laboratory blood gas and chemistry measurements remains an issue that is not adequately studied.
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J Clin Monit Comput · Jul 1998
Normothermic cardiopulmonary bypass increases heparin requirements necessary to maintain anticoagulation.
With the practice of warm cardiopulmonary bypass (CPB) at our institution we have observed an apparent increase in heparin requirements. CPB temperature predictability affects pharmacokinetics and differences in drug metabolism can be expected. We hypothesized that heparin requirements would increase with increasing CPB temperature. ⋯ Maintenance of adequate heparin anticoagulation during CPB is clinically important. Warm CPB patients required more heparin per minute than those undergoing cold CPB. More frequent assessment of anticoagulation and administration of additional heparin should be considered in patients undergoing warm CPB.
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J Clin Monit Comput · Jul 1998
Case ReportsArtifact mistaken for electrical interference recorded from a pulmonary artery catheter.
Artifactual signals superimposed on the electrocardiogram have been well documented [1-5]. These signals can originate from infusion pumps [1, 2], occlusion heads from cardiopulmonary bypass machines [3,4], and dialysis apparatus [5]. ⋯ We report a case in which the blood pressure tracing from the pulmonary artery revealed an artifact that looked at first glance like 60 cycle alternating current (AC) electrical interference. The investigation as to its origin revealed important lessons in the analysis of human error.