Journal of clinical monitoring
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Comparative Study
Arterial pulse contour analysis trending of cardiac output: hemodynamic manipulations during cerebral arteriovenous malformation resection.
Intravascular pressure and cardiac output monitoring are frequently performed in the operating room and intensive care unit. Currently, cardiac output is only measured intermittently, although continuous measurement would be preferable. One method proposed for measuring cardiac output continuously is arterial waveform pulse contour analysis. This study examines the utility of trending cardiac output using pulse contour analysis during manipulations of blood pressure. ⋯ This study demonstrates that during surgery for arteriovenous malformations in the brain, the pulse contour method was able to reflect cardiac output accurately during induced hypotension with esmolol and during restoration of blood pressure with phenylephrine.
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The purpose of this investigation was to study the N2 flux between the patient and the breathing circuit, and the excess gas during N2O anesthesia with the low, fresh gas flow technique. ⋯ Regardless of the fresh gas flow used, sampled gas need not be returned during N2O anesthesia.
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The purpose of this study was to determine the fidelity of pressure signals transmitted through long, narrow (epidural) catheters inserted into the lumbar intrathecal space. ⋯ We found that a catheter of at least 20 gauge connected to a transducer could record pressures in the cerebrospinal fluid compartment with a high degree of fidelity. The prolonged time to reach equilibrium made U-tube manometry unsuitable for clinical use.
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The objective of this study was to test the accuracy and cross-sensitivity of commercially available anesthetic gas monitors. ⋯ The photoacoustic measurement principle is more accurate than the other methods, although the polychromatic infrared analyzers are safer because they detect erroneously selected agents.
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The objective of this study was to prospectively examine the incidence of patient-related failure of pulse oximetry in the postanesthesia care unit (PACU). ⋯ The failure rate and patient characteristics compare favorably with a previously published study of intraoperative pulse oximetry failure. We conclude that while the pulse oximeter is a reliable instrument for the measurement of blood oxygenation, there is a small but consistent incidence of patient-related failure with this monitoring device in the PACU.