Journal of clinical monitoring
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although the waveform derived from a peripheral pulse monitor or pulse oximeter may resemble an arterial pressure waveform, it is in fact a visualization of blood volume change in transilluminated tissue caused by passage of blood: an indication of perfusion or blood flow. Most currently available pulse oximeters indicate this flow, but few display it in usable form. Since adequate tissue blood flow is a prerequisite for normal metabolic activity, it is a parameter that should merit a place in standard anesthesia or intensive care monitors. ⋯ The importance and application of the Valsalva effect on the waveform is emphasized. This effect is particularly applicable for monitoring adequate fluid loading and the action of vasodilator drugs, which are both important in anesthesia. Differences between the arterial pulse pressure wave and tissue flow wave are discussed, as well as the cause of certain artifacts, including the wandering dicrotic notch.
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There is no data on the use of hospital-wide online medical record (OLMR) systems by anesthesiologists. We measured how often anesthesiologists accessed the OLMR database maintained by the hospital, how often data was copied from this database into the clinic's computer system, and how much data was copied. ⋯ We conclude that anesthesiologists, given even crude graphical access to a hospital OLMR data-base, will retrieve and copy data, potentially increasing the accuracy of the medical records and saving time.
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To study the usefulness of three electro-encephalographic descriptors, the average median frequency, the average 90% spectral edge frequency, and a bispectral variable were used with the anesthetic concentrations in estimating the depth of anesthesia. ⋯ The bispectral variable seems to reduce the non-linearity in the boundary separating the class of non-responders from the class of responders. Consequently, the neural network based on the bispectral variable is less complex than the neural network that uses a power spectral variable as one of its inputs.
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Comparative Study
Reproducibility of thermodilution cardiac output determination in critically ill patients: comparison between bolus and continuous method.
A semi-continuous thermodilution method (CCO) was recently developed to measure cardiac output with less risk of bacterial contamination, fluid overload, and user-induced errors than the classical bolus technique (BCO). Previous comparison between these two methods showed negligible bias. However, large limits of agreement suggest that the two methods are not interchangeable. We hypothesized that this poor agreement may be due to differences in reproducibility. ⋯ Differences in reproducibility may explain the poor agreement between the CCO and BCO methods. The better reproducibility of the CCO method allows the detection of smaller variations in cardiac output and suggests the superiority of this new method.