Anaesthesia
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Some military anaesthetists have started to use the Oxford Miniature Vaporiser in a pushover configuration with the Triservice anaesthetic apparatus. This vaporiser performs identically in the pushover and drawover configurations with the Cape TC 50 ventilator. We tested the Oxford Miniature Vaporiser with three other ventilators and found variable performance. When used in the pushover configuration with the Laerdal bag at normal minute volumes, the Oxford Miniature Vaporiser delivers a higher than set output.
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Comparative Study
Supplementary oxygenation with the laryngeal mask airway: a comparison of four devices.
The provision of supplementary oxygen via the laryngeal mask airway used in the recovery room is important for patient safety. Several devices have been described for this purpose, but these studies have not included an accurate measurement of the most clinically important variable, the end-tidal oxygen concentration. ⋯ The performances of the T-bag and the T-piece were superior to those of the filter and Hudson mask, with end-tidal oxygen concentrations of 46.1%, 45.8% and 35.4%, 34.8%, respectively, at 8 l.min-1. Single point assessments of oxygen delivery, such as peak inspired oxygen concentration, may overestimate the efficacy of test devices.
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The sevoflurane alveolar concentration needed for tracheal intubation with remifentanil was studied in 26 adult patients premedicated with 100 mg hydroxyzine. Anaesthesia was induced with sevoflurane in oxygen. The concentration was determined by Dixon's up-and-down method. ⋯ The concentration for acceptable intubating conditions was 2.5 +/- 0.7%. From logistic regression, ED50 and ED95 were 2.0% (95% CI 1.3-2.5) and 3.2% (95% CI 2.6-5.6), respectively. With sevoflurane 2.5%, heart rate and mean arterial pressure decreased by 18% and 15%, respectively, after remifentanil administration and increased slightly after tracheal intubation.