Anesthesiology
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Randomized Controlled Trial Comparative Study Clinical Trial
Epidural meperidine after cesarean section. A dose-response study.
Epidural meperidine is effective for postoperative analgesia, but the optimum dose has not been evaluated. ⋯ Epidural meperidine provides effective postoperative analgesia, although of relatively short duration. A single dose of 25 mg is superior to 12.5 mg, but there is no benefit from increasing the dose to 50 mg or greater.
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Randomized Controlled Trial Comparative Study Clinical Trial
Thermoregulatory vasoconstriction does not impede core warming during cutaneous heating.
Although forced-air warming rapidly increases intraoperative core temperatures, it is reportedly ineffective postoperatively. A major difference between these two periods is that arteriovenous shunts are usually dilated during surgery, whereas vasoconstriction is uniform in hypothermic postoperative patients. Vasoconstriction may decrease efficacy of warming because its major physiologic purposes are to reduce cutaneous heat transfer and restrict heat transfer between the two thermal compartments. Accordingly, we tested the hypothesis that thermoregulatory vasoconstriction decreases cutaneous transfer of applied heat and restricts peripheral-to-core flow of heat, thereby delaying and reducing the increase in core temperature. ⋯ The authors failed to confirm their hypothesis that thermoregulatory vasoconstriction decreases cutaneous transfer of applied heat and restricts peripheral-to-core flow of heat in anesthetized subjects. The reported difference between intraoperative and postoperative rewarming efficacy may result from nonthermoregulatory anesthetic-induced vasodilation.
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Randomized Controlled Trial Clinical Trial
Interaction between intrathecal neostigmine and epidural clonidine in human volunteers.
alpha 2-Adrenergic agonists are thought to produce analgesia, in part, by activating spinal acetylcholine release. The purpose of the current study was to examine the interaction between intrathecal neostigmine and epidural clonidine for analgesia and side effects in humans. ⋯ These results support enhancement of alpha 2-adrenergic analgesia by intrathecal neostigmine, but do not demonstrate synergy, as observed in animals. Lack of enhancement of side effects suggests this combination may be clinically useful.
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Randomized Controlled Trial Multicenter Study Comparative Study Clinical Trial
Intravenous ondansetron in established postoperative emesis in children. S3A-381 Study Group.
In pediatric postsurgical patients, postoperative vomiting is a common occurrence that can delay recovery and result in unplanned hospital admissions after outpatient surgery. This randomized, double-blind, placebo-controlled, multicenter study evaluated the efficacy and safety of ondansetron in the control of established postoperative emesis in outpatients aged 2-12 yr. ⋯ A single dose of ondansetron (0.1 mg/kg up to 4 mg) is effective and well tolerated in the prevention of further episodes of postoperative emesis in children after outpatient surgery. Administration of ondansetron also may result in a shorter time to discharge.
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Randomized Controlled Trial Clinical Trial
Simulation of an epidural test dose with intravenous isoproterenol in awake and in halothane-anesthetized children.
An epidural test dose containing epinephrine does not reliably produce hemodynamic responses in children under halothane anesthesia. The purpose of this study was to determine hemodynamic responses to intravenous isoproterenol in both awake and halothane-anesthetized children. ⋯ Isoproterenol at a dose of 0.1 microgram/kg is a sensitive indicator for intravascular injection of a test dose in children anesthetized with halothane and nitrous oxide. Isoproterenol at a dose of 0.05 microgram/kg approximates a minimal effective dose in awake children and in infants. After detailed studies on neural toxicity, isoproterenol could be of value as an epidural test agent in children.