Anesthesiology
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Randomized Controlled Trial Clinical Trial
Thermoregulatory thresholds for vasoconstriction in patients anesthetized with various 1-minimum alveolar concentration combinations of xenon, nitrous oxide, and isoflurane.
Nitrous oxide limits intraoperative hypothermia because the vasoconstriction threshold with nitrous oxide is higher than with equi-minimum alveolar concentrations of sevoflurane or isoflurane, presumably because of its stimulating actions on the sympathetic nervous system. Xenon, in contrast, does not cause sympathetic activation. Therefore, the authors tested the hypothesis that the vasoconstriction threshold during xenon-isoflurane anesthesia is less than during nitrous oxide-isoflurane anesthesia or isoflurane alone. ⋯ Xenon inhibits thermoregulatory control more than isoflurane, whereas nitrous oxide is the least effective in this respect.
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Multicenter Study
A new noninvasive method to measure blood pressure: results of a multicenter trial.
Blood pressure (BP) monitoring with arterial waveform display requires an arterial cannula. We evaluated a new noninvasive device, Vasotrac (Medwave, Arden Hills, MN) that provides BP measurements approximately every 12-15 beats and displays pulse rate and a calibrated arterial waveform for each BP measurement. ⋯ In surgical and critically ill patients, the Vasotrac measured BP, pulse rate, and displayed radial artery waveform, which was similar to direct radial arterial measurements. It should be a suitable device to measure BP frequently in a noninvasive fashion.
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Randomized Controlled Trial Clinical Trial
Additive contribution of nitrous oxide to sevoflurane minimum alveolar concentration for tracheal intubation in children.
To study the interaction between nitrous oxide and sevoflurane during trachea intubation, the authors determined the minimum alveolar concentration of sevoflurane for tracheal intubation (MAC(TI)) with and without nitrous oxide in children. ⋯ We conclude that nitrous oxide and sevoflurane suppress the responses to tracheal intubation in a linear and additive fashion in children.
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Randomized Controlled Trial Comparative Study Clinical Trial
Preoxygenation: comparison of maximal breathing and tidal volume breathing techniques.
Preoxygenation with tidal volume breathing for 3-5 min is recommended by Hamilton and Eastwood. This report compares tidal volume preoxygenation technique with deep breathing techniques for 30-60 s. ⋯ Rapid preoxygenation with the eight deep breaths within 60 s can be used as an alternative to the traditional 3-min technique.
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Randomized Controlled Trial Clinical Trial
Clinical assessment of a plastic optical fiber stylet for human tracheal intubation.
The authors compared the performance of a prototype intubation aid that incorporated plastic illumination and image guides into a stylet with fiberoptic bronchoscopy and direct laryngoscopy for tracheal intubation by novice users. ⋯ Novices using the imaging stylet produce fewer cases of sore throat (compared with direct laryngoscopy) and can intubate faster than when using a bronchoscope in anesthetized adult patients. The imaging stylet may be a useful aid for tracheal intubation, especially for those unable to maintain skills with a bronchoscope.