Journal of clinical monitoring and computing
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J Clin Monit Comput · Jun 2011
Noninvasive intracranial pressure measurement using infrasonic emissions from the tympanic membrane.
We investigated whether ICP can be assessed by measuring infrasonic emissions from the tympanic membrane. ⋯ It is conceivable that the assessment of infrasonic emissions will become suitable both as a screening tool and for the continuous monitoring of ICP in an intensive care environment.
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J Clin Monit Comput · Jun 2011
Randomized Controlled TrialTitration of sevoflurane in elderly patients: blinded, randomized clinical trial, in non-cardiac surgery after beta-adrenergic blockade.
Monitoring depth of anesthesia via the processed electroencephalogram (EEG) has been found useful in reducing the amount of anesthetic drugs, optimizing wake-up times, and, in some studies, reducing awareness. Our goal was to determine if titrating sevoflurane as the maintenance anesthetic to a depth of anesthesia monitor (SEDLine™, Masimo, CA) would shorten time to extubation in elderly patients undergoing non-cardiac surgery while on beta-adrenergic blockade. This patient population was selected because the usual cardiovascular signs of inadequate general anesthesia may be masked by beta-blocker therapy. ⋯ Use of the SEDLine™ monitor's data to titrate sevoflurane did not improve the time to extubation or change short-term outcome of geriatric surgical patients receiving beta-adrenergic blockers. (ClinicalTrials.gov number, NCT00938782).
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The Lightman is intended to test the optical and electrical properties of a pulse oximeter probe including the wavelength of the light emitting diode by means of a micro spectrometer. The aim of this study was to evaluate the ability of the Lightman to detect faulty pulse oximeter finger probes by testing the accuracy of the wavelength of the light emitting diode in isolation from the monitor. ⋯ Our findings suggest that the Lightman can detect faulty probes and predict reasonably accurately the direction of the probe's error. The Lightman may be considered as a useful tool to assess the accuracy of pulse oximeters. The national survey highlighted a wide variation in the testing procedure utilised to evaluate the accuracy of pulse oximeters. Introduction of guidelines regarding the testing procedure would promote a uniform practice.
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J Clin Monit Comput · Jun 2011
Power spectral analysis of plethysmographic pulse waveform in pregnant women.
To investigate the effect of pregnancy on the pulse wave of the mother. ⋯ The power of harmonics of pulse wave can be described by an exponential decay function with respect to the order of harmonics in both non-pregnant and pregnant women. The effects of pregnancy on the pulse wave are the reduction in the total power of pulse and the power of higher order harmonics, and the increase in the power of lower order harmonics in the power spectrum of pulse wave. This effect of pregnancy on the pulse wave might be caused by the decrease in vascular resistance during pregnancy, the increase in workload on the heart due to increased demand of the growing fetus, and the aortocaval compression caused by the progressively enlarged gravid uterus and fetus.
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J Clin Monit Comput · Jun 2011
Assessment of cerebral oxygenation using near infrared spectroscopy during isovolemic hemodilution in pediatric patients.
One means of limiting the need for allogeneic blood transfusions is isovolemic hemodilution where blood is removed in the operating room and replaced with isotonic fluids to maintain euvolemia. Although the delivery of oxygen to the tissues is generally maintained by compensatory physiologic mechanisms, there are limited data evaluating tissue oxygenation in actual clinical practice. The current study evaluates the effects of isovolemic hemodilution on cerebral oxygenation using near-infrared spectroscopy (NIRS). ⋯ Our data provides preliminary evidence supporting the safety of moderate isovolemic hemodilution in a pediatric population. We found that cerebral oxygenation is well maintained by compensatory mechanisms. Modalities such as NIRS to monitor end-organ oxygenation may be particularly valuable in patients with co-morbid disease processes which may affect end organ oxygenation or prevent the compensatory mechanisms that maintain oxygen delivery during anemia.