Journal of clinical monitoring and computing
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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
Hydraulic analog for simultaneous representation of pharmacokinetics and pharmacodynamics: application to vecuronium.
To facilitate teaching the pharmacologic determinants of clinically observed drug effect, we expand on the hydraulic representation of the pharmacokinetics and pharmacodynamics of intravenous drugs. ⋯ In the described hydraulic analog, fluid delivered into a central reservoir is representative of drug infusion, and the heights of the fluid columns in the central and peripheral reservoirs are representative of the drug concentrations in the corresponding pharmacologic compartments. The height of the fluid column in an 'effect reservoir' is representative of the apparent effect site concentration in a simultaneous pharmacokinetic-pharmacodynamic model. A non-linear scale on the effect reservoir represents the relationship between the effect site concentration and the clinical effect. Reservoir surface areas are equivalent to volumes of distribution and hydraulic resistances are inversely proportional to drug clearances. The proof of mathematical equivalency of the presented analog to simultaneous pharmacokinetic-pharmacodynamic models is given in an appendix. ILLUSTRATION OF THE EDUCATIONAL APPLICATION: The effect window can represent monitored twitch response following the administration of a neuromuscular blocking agent. Using pharmacokinetic-pharmacodynamic parameter values for vecuronium, we demonstrate how the hydraulic analog can be used to explain the priming principle and the clinically observed time-course disparity of two effect sites: the larynx and the adductor pollicis. (A companion web site: http://www.anest.ufl.edu/ha.html presents an interactive animation of the described analog.)
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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.
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J Clin Monit Comput · Jul 1998
Letter Randomized Controlled Trial Clinical TrialEffect of ketamine on bispectral index and levels of sedation.