British journal of anaesthesia
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Historical Article
A short history of fires and explosions caused by anaesthetic agents.
The first recorded fire resulting from the use of an anaesthetic agent occurred in 1850, when ether caught fire during a facial operation. Many subsequent fires and explosions have been reported, caused by ether, acetylene, ethylene and cyclopropane, and there has been one reported explosion involving halothane. ⋯ The use of flammable agents has decreased significantly in recent years and although fires and explosions from nonanaesthetic causes, for example gastrointestinal gases, skin sterilizing agents and laser surgery, may continue to occur, those from gaseous and volatile anaesthetic agents may now be of historical interest only. This article reviews some of the more relevant and enlightening reports of the past 150 yr.
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In order to study the neuromuscular interactions between suxamethonium and magnesium sulphate (MgSO4), we have determined the dose-response relationship of suxamethonium and the neuromuscular actions of 1.25 x ED50 dose of suxamethonium, both before and after pretreatment with MgSO4. We have also compared the effect of 1.25 x ED50 dose of suxamethonium in the absence and in the presence of 50% neuromuscular block, established previously by infusion of MgSO4. Twenty-one cats were anaesthetized with urethane. ⋯ Twitch depression produced by 1.25 x ED50 dose of suxamethonium decreased significantly with MgSO4 pretreatment, from 76.7 (2.6)% before MgSO4 to 61.7 (6.4)% after MgSO4 60 mg kg-1 and 48.7 (7.5)% after MgSO4 90 mg kg-1 (P < 0.05). With stable 50% neuromuscular block, established previously by infusion of MgSO4, the 1.25 x ED50 dose of suxamethonium produced more twitch augmentation (133 (6.3)% vs 108.3 (1.3)%; P < 0.05) and less twitch depression (31.6 (9.6)% vs 74.1 (0.6)%, P < 0.05) than in the absence of MgSO4. The results of all three methods demonstrated that the pharmacological interaction between suxamethonium and magnesium was antagonistic.