British journal of anaesthesia
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Comparative Study
The effects of sevoflurane are similar to those of isoflurane on the neuromuscular block produced by vecuronium.
We have examined the interactions of 1 MAC of isoflurane and sevoflurane (and 66% nitrous oxide in oxygen) with vecuronium, using the EMG response of the abductor digiti minimi to train-of-four (TOF) stimulation of the ulnar nerve. We constructed dose-response curves for vecuronium in 54 patients. ⋯ The rate of recovery of T4:T1 was significantly greater when both anaesthetics were discontinued. However, this rate was similar for both anaesthetics, suggesting that the mechanism of action of the two anaesthetics is similar.
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Randomized Controlled Trial Comparative Study Clinical Trial
Risk of aspiration with the laryngeal mask.
In order to assess if the use of the laryngeal mask airway is associated with an increased risk of gastric regurgitation during mechanical ventilation, we studied 50 patients allocated randomly to undergo anaesthesia with either artificial ventilation with isoflurane and nitrous oxide in oxygen and atracurium (group A) or spontaneous ventilation with isoflurane and nitrous oxide in oxygen (group B). In both groups a laryngeal mask airway was used. ⋯ In one patient in each group, there was staining of the oropharynx with blue dye at the end of surgery. In the patient in group A, dye was present in the trachea and bronchi.
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We have described the design and design considerations of the desflurane Tec 6 "vaporizer" and have tested its performance characteristics. The vaporizer differs from previous vaporizers designed for anaesthesia in that electromechanical rather than mechanical controls accommodate the different physical characteristics of desflurane. This design, while offering perhaps an increased risk of failure (owing to sophisticated electronic components and circuitry), on the other hand offers the decreased likelihood of accidental delivery of very large concentrations of liquid anaesthetic resulting from tilting or overfilling and alarms and warnings not previously incorporated into the design of anaesthetic vaporizers. The output characteristics of the vaporizer are as expected, based on the design: desflurane concentration output in oxygen has accuracy (+/- 15%) which is similar to that of the mechanical vaporizers; output decreases when nitrous oxide is added owing to the lower viscosity, but remains within 20% of the dial setting or 0.5% absolute.
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Randomized Controlled Trial Comparative Study Clinical Trial
Tracheal intubation without neuromuscular block in children.
We have studied 80 healthy children, aged 2-14 yr, undergoing adenotonsillectomy in a double-blind, randomized design. Tracheal intubation facilitated by either suxamethonium 1.5 mg kg-1 or alfentanil 15 micrograms kg-1 was compared after induction of anaesthesia with propofol 3-4 mg kg-1. ⋯ Fewer patients coughed (P < 0.014) and limb movement was less common (P < 0.007) after tracheal intubation facilitated by suxamethonium. Alfentanil attenuated the haemodynamic responses to tracheal intubation.
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Randomized Controlled Trial Comparative Study Clinical Trial
Comparison of desflurane and fentanyl-based anaesthetic techniques for coronary artery bypass surgery.
We have compared, in 51 ASA II and III patients undergoing coronary artery bypass surgery, an inhaled anaesthetic technique based on desflurane, supplemented with low-dose (10 micrograms kg-1) fentanyl, with an i.v. technique using high-dose (50 micrograms kg-1) fentanyl with midazolam for induction. Satisfactory records were available for analysis in 50 patients. There were no differences between groups in operating time, cardiopulmonary bypass time, aortic cross-clamp time or duration of stay in the intensive care unit after surgery. ⋯ This was always lower than the fentanyl group by 5-15 beat min-1 and the difference was significant at induction, during skin preparation and before aortic cannulation. In comparison with the desflurane group, cardiac index was significantly greater in the fentanyl group at induction, laryngoscopy and during skin preparation, but was significantly less before aortic cannulation. The need for vasodilator intervention was significantly more common in the fentanyl group before, during and after cardiopulmonary bypass and for beta adrenoceptor block before cardiopulmonary bypass.(ABSTRACT TRUNCATED AT 250 WORDS)