British journal of anaesthesia
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Randomized Controlled Trial Comparative Study Clinical Trial
New patch delivery system for percutaneous local anaesthesia.
We have assessed the release of amethocaine from a new patch delivery system and subsequent drug diffusion through human stratum corneum and whole skin. We found that the patch system was more efficient than an amethocaine gel preparation. ⋯ Furthermore, a 30-min application of the patch was sufficient to provide profound and prolonged topical anaesthesia in all volunteers. In contrast, although a 60-min application of EMLA was necessary to ensure satisfactory onset of percutaneous anaesthesia, the duration of action was much shorter than that of the amethocaine patch.
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Randomized Controlled Trial Comparative Study Clinical Trial
Presurgical analgesia in children subjected to hypospadias repair.
We have examined the use of different pre-surgical analgesic techniques in 30 children aged 2-10 yr undergoing repair of hypospadias. They were allocated randomly, in a double-blind, placebo-controlled study, to receive one of three analgesic techniques (n = 10): lumbar extradural analgesia using 0.5% bupivacaine 1 mg kg-1 plus morphine 50 micrograms kg-1; morphine 100 micrograms kg-1 i.m.; or subpubic block using 0.5% bupivacaine 0.5 mg kg-1 for each side. ⋯ Children given extradural analgesia had more stable haemodynamic variables and smaller catecholamine concentrations and needed less anaesthetic supplementation, with no analgesic requirement in the postoperative period. Nausea or vomiting were not reported in children given subpubic block.
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Using the Brüel & Kjaer Anaesthetic Gas Monitor type 1304, we have monitored the output of 94 anaesthetic agent vaporizers (Fluotec 3:58, Enfluratec 3:24, Isotec 3:12), in seven departments of anaesthesia, at different dial settings and flow rates. The range of output, for one type of vaporizer and dial setting (flow: 6 litre min-1) was largest with the Fluotec 3 (0.85-1.55% when dial set to 1%) and smallest with the Isotec 3 (0.85-1.15% when dial set to 1%). In determining the number of vaporizers with unacceptable inaccuracy, we applied acceptance limits of +/- 15% relative on each vaporizer and each dial setting. ⋯ Even when some specific conditions (vaporizers giving output beyond the limits at any two or more dial settings; output beyond the limits in the clinically relevant range (0.5-2%)) were added, a substantial number of vaporizers did not perform within the limits. We found a significantly greater accuracy of the vaporizers after 3-monthly calibration checks (P < 0.05) compared with vaporizers undergoing service and calibration only annually. Using a questionnaire, we found that fewer than 30% of the anaesthetists using the vaporizers would accept aberrance beyond +/- 10% relative of the dial setting.
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Randomized Controlled Trial Clinical Trial
Synergism between atracurium and vecuronium in children.
In 30 children under balanced anaesthesia, we have determined dose-response curves and maintenance requirement of three dose ratio combinations of atracurium and vecuronium (10:1, 4:1 or 1.6:1 on a microgram:microgram basis). Neuromuscular block was monitored by adductor pollicis EMG. An equipotent dose ratio (4:1) was most potent, with a mean (SEM) ED95 of atracurium 95 (6) micrograms kg-1 with vecuronium 24 (1) micrograms kg-1. ⋯ These results indicate that a combination of atracurium and vecuronium is supra-additive compared with the effects of each drug alone. However, all combinations maintained an intermediate character of neuromuscular block. Combining atracurium with vecuronium may reduce drug requirement by 40%.