Anesthesiology
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Previous studies have shown that specific amino acid residues in the putative second transmembrane segment (TM2) of the gamma-aminobutyric acid receptor type A (GABAA) receptor play a critical role in the enhancement of GABAA receptor function by halothane, enflurane, and isoflurane. However, very little is known about the actions of sevoflurane and desflurane on recombinant GABAA receptors. The aim of this study was to examine the effects of sevoflurane and desflurane on potentiation of GABA-induced responses in the wild-type GABAA receptor and in receptors mutated in TM2 of the alpha1, alpha 2, or beta 2 subunits. ⋯ Positions Ser270 of the GABAA alpha1 and alpha2 subunits, but not Asn265 in the TM2 of the beta2 subunit, are critical for regulation of the GABAA receptor by sevoflurane and desflurane, as well as isoflurane, consistent with the idea that these three volatile anesthetics share a common site of actions on the alpha subunit of the GABAA receptor.
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The purpose of this study was to determine the changes in the plasma concentration of rocuronium and the reversal of its neuromuscular blockade after the intravenous infusion of Org 25969, the novel neuromuscular block-reversal agent, in anesthetized guinea pigs. ⋯ The authors propose that the capture of rocuronium by Org 25969 causes the rapid reversal of neuromuscular block. The reversal can be explained by the rapid transfer of free rocuronium from the effect compartment (neuromuscular junction) to the central compartment, in which it is bound to Org 25969. This explains the increase in total plasma concentration of rocuronium (free and bound to Org 25969).
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Anaphylactic and anaphylactoid reactions occurring during anesthesia remain a major cause of concern for anesthesiologists. The authors report the results of a 2-yr survey of such reactions observed during anesthesia in France. ⋯ These results further corroborate the need for systematic screening in the case of anaphylactoid reaction during anesthesia and for the constitution of allergoanesthesia centers to provide expert advice to anesthesiologists and allergists.
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During hemorrhagic hypotension, sympathetic vasoconstriction crucially contributes to gut mucosal damage. Sympathetic blockade by thoracic epidural anesthesia has been shown to increase mucosal microvascular perfusion and to improve survival after severe hemorrhage in laboratory animals. This study investigates the effects of thoracic epidural anesthesia on intestinal microvascular perfusion during hemorrhagic hypotension in rats. ⋯ During hemorrhagic hypotension and after resuscitation, thoracic epidural anesthesia has beneficial effects on intestinal microvascular perfusion. Because of blockade of sympathetic nerves, thoracic epidural anesthesia prevents perfusion impairment of the muscularis during hypotension and attenuates leukocyte rolling after resuscitation.
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Clinical Trial
Pharmacokinetics of propofol administered by target-controlled infusion to alcoholic patients.
Chronic alcoholic patients are frequently presented for anesthesia and surgery. These patients require higher doses of propofol than control patients for induction of anesthesia, but whether this is because of changes in pharmacokinetics or pharmacodynamics is not known. This study was designed to investigate the influence of chronic ethanol intake on propofol pharmacokinetics. ⋯ Chronic alcoholism induces only mild changes in the pharmacokinetics of propofol. Conversely, propofol pharmacokinetics are markedly different during anesthesia and surgery or after opening eyes in the recovery period.