Anaesthesia
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This study was conducted to investigate the effect of voluntary tetanus on the recovery from neuromuscular block produced by a nondepolarising drug, vecuronium, in the isolated forearm. We have studied the recovery indices and train of four fade at different levels of recovery following vecuronium in both isolated forearms simultaneously, in six sets of experiments. In one hand the volunteer performed a maximum contraction of his thumb repeatedly at fixed intervals. ⋯ The train-of-four fade also showed a sustained reduction in the isolated forearm which underwent voluntary tetanus. During the later phase of recovery the train-of-four fade showed significant difference statistically (p < 0.01). The findings of this study supports the hypothesis that more rapid recovery associated with voluntary tetanus is due to a reduction in the presynaptic block thus resulting in an increased rate of transmitter release.
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Randomized Controlled Trial Comparative Study Clinical Trial
A comparison between mivacurium and suxamethonium in children.
The neuromuscular effects of mivacurium were compared with those of suxamethonium in 69 children (aged 2-12 years), during nitrous oxide, oxygen and halothane anaesthesia in a randomised open study. Neuromuscular block was monitored by measuring the acceleration of the thumb caused by contraction of the adductor pollicis muscle after supramaximal stimulation of the ulnar nerve at the wrist using an Accelograph. End-tidal carbon dioxide was maintained at about 4 kPa in both groups. ⋯ The range of maximum block was similar for both drugs. The average time to reach maximum block was 143 s for mivacurium and 56 s for suxamethonium. Intubating conditions were similar in the two groups.
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We questioned 50 anaesthetic staff about the costs of consumables used in routine anaesthetic practice. By means of a questionnaire staff were asked for estimates of the cost of 28 drugs, fluids and disposables. The responses were more accurate than in previous surveys; 47% of all the estimated costs were within 50% of the actual costs and 75% were within 100%. ⋯ However, allowing for inflation, the cost today is actually equivalent to the cost in 1959. Since 1980 there has been no consistent pattern in drug prices, with some prices remaining the same, others falling and some increasing; all are, however, cheaper in real terms. It is possible to make substantial savings by using the more expensive drugs judiciously and by encouraging the use of low-flow, closed-circuit anaesthetic systems.
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The forces required to break and to remove catheters from epidural spaces were investigated. Provided the patient's back is fully flexed and a slow steady pull is applied to the epidural catheter, the extraction forces required at both thoracic and lumbar levels are well below the minimum force required to break the same catheters.