British journal of anaesthesia
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Randomized Controlled Trial Comparative Study Clinical Trial
Comparison of large dose of vecuronium with pancuronium for prolonged neuromuscular blockade.
Dose-duration relationships for vecuronium were determined and the duration of action produced by vecuronium 0.3 mg kg-1 shown to equal that of pancuronium 0.1 mg kg-1. Using these doses, the neuromuscular blocking properties and cardiovascular effects of the two drugs were compared. With large dose administration of vecuronium (0.3 mg kg-1), both the onset time (mean 81 s) and the 25-75% recovery index (mean 13.9 min) were about one-half those associated with pancuronium (mean 168.5 s and 29.3 min, respectively). ⋯ There was no evidence of cardiovascular instability with the large dose of vecuronium. Heart rate, however, was significantly slower (range 89.7-94.2% of control) 2-20 min after the injection of vecuronium. Vecuronium 0.3 mg kg-1 may have more favourable neuromuscular blocking effects than pancuronium 0.1 mg kg-1 and may be preferable to pancuronium when prolonged neuromuscular blockade is required.
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Randomized Controlled Trial Comparative Study Clinical Trial
Extradural bupivacaine or lignocaine anaesthesia for elective caesarean section: the role of maternal posture.
Extradural anaesthesia was induced in 64 patients in either the sitting or the lateral position, for elective Caesarean section with either 0.5% plain bupivacaine or 2% lignocaine with adrenaline 1 in 200,000. Onset was significantly shorter and a significantly greater number of patients were ready for surgery within 35 min following injection of lignocaine in the lateral position. ⋯ Significantly more patients who had received the first injection of local anaesthetic agent in the sitting position required ephedrine to correct maternal hypotension. Most frequently, hypotension coincided with transfer of patients to theatre and thus was associated with movement of the patient in the presence of extensive sympathetic block.
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Comparative Study
Haemodynamic and heart rate reflex responses to propofol in the rabbit. Comparison with althesin.
Propofol was administered to eight rabbits by constant i.v. infusion at 0.2, 0.4 and 0.6 mg kg-1 min-1 to produce light sedation. The lowest dose was compared with an infusion of Althesin 0.1 mg kg-1 min-1. The rabbits had been previously implanted with aortic and vena caval perivascular balloon cuffs to examine the baroreceptor-heart rate reflex and an aortic thermistor catheter for cardiac output (CO) measurements. ⋯ A dose-related reduction in the range and gain of the baroreceptor-heart rate reflex was observed with propofol (P less than 0.05). The pattern of alteration of the reflex curve, however, differed between the two anaesthetics and the vagal efferent component was more resistant to blockade with propofol. The relative preservation of baroreceptor reflex responses, and the reduction in TPR by a reduction of resting constrictor tone, suggest propofol may have significant clinical advantages when used as a sedative infusion.
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The amount of larynx seen at intubation was assessed in 633 adult patients undergoing routine surgery. Various measurements of the head and neck were made in an attempt to discover which features were associated with difficulty with laryngoscopy (defined as the inability to see even the arytenoids). ⋯ A simple predictive rule was developed and tested on a prospective set of 778 patients, in 1.5% of whom laryngoscopy was found to be difficult. Depending on the threshold chosen, the rule allowed the detection of, for example, 75% of the "difficult" laryngoscopies at a cost of falsely identifying 12% of the "not difficult" patients.