Anesthesiology
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Randomized Controlled Trial Comparative Study Clinical Trial
Prophylactic antiemetic treatment with ondansetron in children undergoing tonsillectomy.
Children undergoing tonsillectomy are at high risk for postoperative vomiting. This study was undertaken to compare ondansetron with metoclopramide and droperidol for the prevention of postoperative vomiting after tonsillectomy. ⋯ The intravenous administration of ondansetron 0.15 mg.kg-1 is highly effective in reducing postoperative emesis in children undergoing tonsillectomy. Metoclopramide and droperidol at the doses tested are ineffective in this population.
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Randomized Controlled Trial Comparative Study Clinical Trial
Diuretic effect of clonidine during isoflurane, nitrous oxide, and oxygen anesthesia.
Because clonidine, a relative selective alpha 2-agonist, inhibits the action of arginine vasopressin (AVP), the authors examined whether clonidine as an oral preanesthetic medication would induce diuresis and also would affect AVP release and its action during general anesthesia. ⋯ Oral preanesthetic medication of clonidine 2.5 or 5 micrograms.kg-1 caused a significant diuretic effect during surgery under general anesthesia, though it did not apparently relate to AVP action. This effect of clonidine could be related to its pharmacological action as an alpha 2-adrenoceptor agonist not necessarily restricted to the kidney. The diuretic effect of clonidine implicates its clinical importance in the management of patients during anesthesia.
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Randomized Controlled Trial Clinical Trial
Repetitive rapid increases in desflurane concentration blunt transient cardiovascular stimulation in humans.
Rapid increases in desflurane concentrations above minimum alveolar concentration (MAC) can cause transient (2-4-min) circulatory changes, possibly from stimulation of rapidly-adapting airway receptors. We hypothesized that the initial increase in concentration would produce greater changes than subsequent increases. ⋯ An initial rapid increase in desflurane to 1.1 MAC produces much more stimulation than do subsequent increases, regardless of the presence of nitrous oxide. The decreased response is consistent with the hypothesis that stimulation of rapidly-adapting airway receptors produce the initial response.
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Randomized Controlled Trial Comparative Study Clinical Trial
Effects of ondansetron in the prevention of postoperative nausea and vomiting in children.
Postoperative nausea and vomiting (PONV) is a commonly observed adverse effect of general anesthesia. Recently, ondansetron, a new serotonin3 (5-hydroxytryptamine3) receptor antagonist was shown to be effective in the prophylaxis and prevention of chemotherapy-induced nausea and vomiting in children and adults as well as of PONV in adults. The aim of the current study was to evaluate the capacity of ondansetron to prevent PONV in pediatric patients. ⋯ Ondansetron is effective in the prevention of PONV in pediatric patients for the first 4 h after general anesthesia. Lower sedation scores with ondansetron compared with droperidol may be an advantage, especially in ambulatory surgery. However, the incidence of late-onset PONV (> 4-24 h) was not influenced by prophylactic treatment with one dose of ondansetron preoperatively.
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Randomized Controlled Trial Clinical Trial
The interaction of fentanyl on the Cp50 of propofol for loss of consciousness and skin incision.
We have previously demonstrated that the minimum alveolar concentration of isoflurane at 1 atm that is required to prevent movement in 50% of patients or animals exposed to a maximal noxious stimulus is markedly reduced by increasing fentanyl concentrations. Total intravenous anesthesia with propofol is increasing in popularity, yet the propofol concentrations required for total intravenous anesthesia or the interaction between propofol and fentanyl have not yet been defined. ⋯ We defined the propofol concentration required for loss of consciousness and showed that it is reduced by increasing fentanyl concentration and by increasing age. The propofol concentration (alone) adequate for skin incision is high but is markedly reduced by fentanyl. A ceiling effect in the Cp50i for propofol is seen with fentanyl concentrations greater than 3 ng/ml.