Anesthesia and analgesia
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Anesthesia and analgesia · Apr 1987
Randomized Controlled Trial Clinical TrialA randomized prospective controlled study of the metabolism and hepatotoxicity of halothane in humans.
In a randomized prospective controlled study in humans, the metabolism and hepatic effects of a single administration of halothane were compared with enflurane and meperidine. Pre- and postoperative antipyrine pharmacokinetics, intraoperative indocyanine green clearance, liver histology, and postoperative liver function tests were determined in 24 patients undergoing abdominal surgery who were randomly allocated to receive either halothane (0.5%, group I), enflurane (0.8%, group II), or meperidine (group III) as a supplement to a common basal anesthetic regimen consisting of thiopental, nitrous oxide/oxygen/muscle relaxant. In addition, end-tidal concentrations of the volatile reductive metabolites of halothane, chlorodifluoroethylene (CDF), and chlorotrifluoroethane (CTF) were determined in group I patients and serum and urinary inorganic fluoride were determined in both group I and II patients. ⋯ There were no significant differences in liver cell morphology (P greater than 0.5) in biopsies taken at the end of stage IV compared with biopsies at the end of stage III, from groups I and II. The results of this study show that reductive metabolism of halothane occurs routinely in patients undergoing halothane anesthesia under conditions of normoxia. This may be the cause of the changes in antipyrine clearance after halothane anesthesia.
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Anesthesia and analgesia · Apr 1987
Blood levels of mepivacaine during continuous epidural anesthesia.
Venous blood concentrations of mepivacaine were measured in 30 patients during 5 hr of surgical anesthesia following either multiple epidural injections of mepivacaine with or without epinephrine or continuous epidural infusion of mepivacaine with epinephrine. Patients were divided into three groups: group 1 initially received 10 or 15 ml followed by 10 ml of 2% plain mepivacaine at 1-hr intervals; group 2 received 10 or 15 ml followed by 10 ml of epinephrine-containing 2% mepivacaine at 1-hr intervals; group 3 received 10 or 15 ml followed by a constant infusion of 10 ml/hr of epinephrine-containing 2% mepivacaine. ⋯ The mean blood concentration of mepivacaine in group 3 remained significantly lower than the concentrations in groups 1 and 2 from 3.5 to 5 hr. These results demonstrate that the blood concentrations of mepivacaine are not reduced by the addition of epinephrine to mepivacaine solutions when intermittent epidural injections are repeated more than four times at 1-hr intervals, but that blood mepivacaine levels are reduced below levels seen with intermittent injections by the continuous epidural infusion of epinephrine-containing mepivacaine.