British journal of anaesthesia
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Randomized Controlled Trial Comparative Study Clinical Trial
Mucosal pressure and oropharyngeal leak pressure with the ProSeal versus laryngeal mask airway in anaesthetized paralysed patients.
The ProSeal laryngeal mask airway (PLMA) is a new laryngeal mask device with a larger, wedge-shaped cuff and a drainage tube. We tested the hypothesis that directly measured mucosal pressure and oropharyngeal leak pressure (OLP) are higher for the PLMA compared with the laryngeal mask airway (LMA). We also assess the mechanism of seal, and the reliability of cuff volume, in vivo intracuff pressure and calculated mucosal pressure (in vivo minus in vitro intracuff pressure) to predict directly measured mucosal pressure. ⋯ Directly measured mucosal pressure was usually lower than OLP for both devices, and there was a positive correlation between directly measured mucosal pressure and OLP. Cuff volume, in vivo intracuff pressure and calculated mucosal pressure were poor to moderate predictors of directly measured mucosal pressure for the LMA and PLMA. We conclude that the PLMA forms a better seal than the LMA without an increase in directly measured mucosal pressure.
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Randomized Controlled Trial Clinical Trial
Randomized study of intravenous fluid preload before epidural analgesia during labour.
We performed a randomized controlled trial of the effect of intravenous fluid preload on maternal hypotension and fetal heart rate (FHR) changes in labour after the first epidural injection. Group 1 (49 women) received 1 litre of crystalloid preload. Group 2 (46 women) received no preload. ⋯ Deterioration in FHR pattern was found in four women in group 1 and 11 in group 2 (P = 0.08). This study has not shown a significant increase in the incidence of hypotension when intravenous preload is omitted before epidural analgesia using a low concentration of bupivacaine during labour. Because of the clinical importance of the difference in the rate of FHR deterioration between the two groups, we continue to administer preload for high-risk cases.
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We investigated the safety of a patient-maintained system that allows individuals to operate a target-controlled infusion of propofol to achieve sedation. Ten healthy volunteers were recruited and instructed to try to anaesthetize themselves with the system. A target-controlled infusion of propofol was set to deliver a target propofol concentration of 1 microgram ml-1, and the subjects allowed to increase the target in increments of 0.2 microgram ml-1 by pressing a control button twice in 1 s. ⋯ Two subjects became oversedated, one of whom was unrousable with loss of eyelash reflex. No subject could recall the keyword, although one recognized it from a list of 10 words. We conclude that the patient-maintained sedation system described could not be guaranteed to produce only conscious sedation in all patients, and that close clinical supervision by an anaesthetist would still be required for safe operation.
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The German Society of Anaesthesiology and Intensive Care Medicine evaluates voluntary, standardized, everyday, perioperative anaesthesia outcome measures. A standard minimal data set is collected for national benchmarking. This article reviews the implementation of a data acquisition system in one academic centre that has participated in this long-term nationwide project since its initiation in 1992. ⋯ However, an extensive data validation system was necessary. IEC reporting results were largely dependent on the documentation culture. The future of outcome tracking in routine anaesthesia may lie in multicentre comparisons with multivariate-adjusted risk and comorbidity data from each provider's integrated information system.