Anaesthesia
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The accuracy of a computer-controlled infusion of midazolam, based on previously published pharmacokinetic parameters, was tested prospectively in 12 adult female patients undergoing general anaesthesia. Anaesthesia consisted of an initial bolus followed by an exponentially decreasing infusion of midazolam given according to body weight, fentanyl, nitrous oxide and vecuronium. Venous blood samples were taken at 15 min-intervals throughout the procedures and for 1-2 h postoperatively. ⋯ Retrospective fitting of an alternative set of published parameters for midazolam resulted in significant deterioration of the model. The precision was similar to that found in past studies of intravenous anaesthetic agents. Further improvement in the accuracy of midazolam infusion awaits improved understanding of the causes of pharmacokinetic variability.
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Comparative Study
Comparison of recovery index of rocuronium or vecuronium with simultaneously administered pancuronium in the isolated forearm.
A series of isolated forearm experiments is described in which rocuronium or vecuronium were injected into one arm, and pancuronium injected simultaneously into the contralateral arm. The time for 25%-75% twitch recovery (recovery index) was recorded in both arms. The recovery indices of rocuronium and vecuronium were similar, but that of pancuronium significantly longer. Because the recovery indices compared in any one experiment occurred in the presence of identical background plasma concentration, the differences observed in recovery index between pancuronium and either rocuronium or vecuronium are due to different rates of dissociation from the effect compartment at the neuromuscular junction.
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Randomized Controlled Trial Multicenter Study Clinical Trial
The effect of oral ondansetron in the prevention of postoperative nausea and vomiting after major gynaecological surgery performed under general anaesthesia.
The efficacy and safety of ondansetron in preventing postoperative nausea and vomiting following major gynaecological surgery was evaluated in this multicentre, double-blind study. A total of 243 patients were randomised to receive three doses of oral ondansetron 8 mg or matching placebo at 8-hourly intervals, with the first dose being given an hour before surgery. A standard general anaesthetic technique was employed throughout. ⋯ Of the 237 patients evaluated for efficacy, significantly fewer ondansetron 8 mg treated patients (65/117; 56%) experienced postoperative nausea and/or vomiting compared with placebo-treated patients (94/120; 78%) during the study period (p < 0.001). In addition, ondansetron 8 mg reduced the severity of nausea (p < 0.001) and the total number of vomiting episodes experienced (p < 0.001). Overall, ondansetron 8 mg was well tolerated and effective in preventing postoperative nausea and vomiting in this surgical setting.
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Randomized Controlled Trial Comparative Study Clinical Trial
A comparison of the laryngeal mask airway and Guedel airway, bag and facemask for manual ventilation following formal training.
Ten volunteers, with no previous experience of resuscitation, were formally trained in the use of the laryngeal mask airway and the oropharyngeal airway (Guedel), bag and facemask for manual ventilation of the lungs in 104 fit, anaesthetised adults. They then used both airways in turn. ⋯ Success rates for the laryngeal mask airway and the Guedel airway, bag and facemask were 87% and 43% respectively (p < 0.001) and the average insertion times were 27.4 s (SEM 1.5) and 15.8 s (SEM 0.50) (no significant difference), respectively. The laryngeal mask airway proved to be easier to use for manual ventilation than the Guedel airway, bag and mask for inexperienced personnel who had received a period of formal training in both techniques.