Anesthesia and analgesia
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Anesthesia and analgesia · Oct 1992
Intraoperative monitoring of tibialis anterior muscle motor evoked responses to transcranial electrical stimulation during partial neuromuscular blockade.
We studied the feasibility of recording motor evoked responses to transcranial electrical stimulation (tce-MERs) during partial neuromuscular blockade (NMB). In 11 patients, compound muscle action potentials were recorded from the tibialis anterior muscle in response to transcranial electrical stimulation during various levels of vecuronium-induced NMB. The level of NMB was assessed by accelerometry of the adductor pollicis muscle after train-of-four stimulation of the ulnar nerve. ⋯ Before administration of vecuronium, the M-response amplitude was 9.6 +/- 3.6 (mean +/- SD) mV, and the tce-MER amplitude was 1.21 +/- 0.66 mV. Although administration of vecuronium (0.05 mg/kg) resulted in loss of the mechanical adductor pollicis response in 8 of the 11 patients, the M-response and the tce-MER remained recordable. Subsequently, during an infusion of vecuronium, adjusted to maintain one or two mechanical responses to train-of-four stimulation, the average M-response to peroneal nerve stimulation was 5.2 +/- 2.5 mV (53% of the control value), and tce-MER amplitude was 0.59 +/- 0.36 mV (59% of the control value).(ABSTRACT TRUNCATED AT 250 WORDS)
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Desflurane causes dose-dependent decreases in cerebrovascular resistance and cerebral metabolic rate of oxygen consumption (CMRO2), suggesting that desflurane is a cerebral arteriolar dilator with global flow-metabolism coupling similar to halothane and isoflurane. Desflurane is also similar to isoflurane in that cerebrovascular responsivity to carbon dioxide appears to be maintained. In the dog, arterial hypotension to 40 mm Hg induced with 2.4 MAC desflurane resulted in global decreases in cerebral blood flow of 60% and CMRO2 of 20%. ⋯ The electroencephalographic effects of desflurane are similar to those of isoflurane in humans, and burst suppression is easily achieved. There are no data available concerning possible interactions between desflurane and the outcome of a cerebral ischemic event. Similar to other potent volatile agents, desflurane can cause cerebral vasodilation and may result in intracranial pressure changes in vulnerable patients, but if adequate hyperventilation and depth of anesthesia are maintained, it is probably safe to use desflurane in a manner similar to isoflurane in patients with decreased intracranial compliance.
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Anesthesia and analgesia · Oct 1992
Randomized Controlled Trial Comparative Study Clinical TrialComparison of desflurane with propofol in outpatients undergoing peripheral orthopedic surgery.
This study was undertaken to compare desflurane with propofol anesthesia in outpatients undergoing peripheral orthopedic surgery. Data were combined from two institutions participating in a multicenter study. Ninety-one patients, ASA physical status I or II, were each randomly assigned to one of four groups. ⋯ Patients in group II experienced less nausea than other groups (P = 0.002) despite this group having required more intraoperative fentanyl supplementation than groups III and IV (P = 0.01). Time to emergence, discharge, and psychometric test results were similar in all groups. Desflurane appears to be comparable with propofol as an outpatient anesthetic, facilitating rapid recovery and discharge home.
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Anesthesia and analgesia · Oct 1992
Randomized Controlled Trial Comparative Study Clinical TrialOndansetron in the treatment of postoperative vomiting: a randomized, double-blind comparison with droperidol and metoclopramide.
The prophylactic antiemetic efficacy of ondansetron was evaluated in a randomized, double-blind comparison with droperidol and metoclopramide in 66 patients undergoing general anesthesia for dilatation and curettage. Ten minutes before induction of anesthesia, 22 patients received a single intravenous dose of 8 mg of ondansetron, 22 others received 1.25 mg of droperidol, and the remaining 22 received 10 mg of metoclopramide. Anesthesia was induced with 3.3-5 mg/kg of intravenous thiopental and maintained with 65% nitrous oxide in oxygen and 2%-3% enflurane. ⋯ There was no statistically significant difference in the incidence of nausea among the groups. Postoperative sedation and well-being scores were not significantly different among the groups. We conclude that preoperative prophylactic administration of ondansetron is superior to droperidol or metoclopramide in the prevention of emetic sequelae after general anesthesia for dilatation and curettage.