Anesthesiology
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Randomized Controlled Trial Clinical Trial
Small, oral dose of clonidine reduces the incidence of intraoperative myocardial ischemia in patients having vascular surgery.
Most new perioperative myocardial ischemic episodes occur in the absence of hypertension or tachycardia. The ability of alpha 2-adrenoceptor agonists to inhibit central sympathetic outflow may benefit patients with coronary artery disease by increasing the myocardial oxygen supply and -demand ratio. ⋯ A small oral dose of clonidine, given prophylactically, can reduce the incidence of perioperative myocardial ischemic episodes without affecting hemodynamic stability in patients with suspected or documented coronary artery disease.
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Randomized Controlled Trial Clinical Trial
Induction of anesthesia and tracheal intubation with sevoflurane in adults.
The speed, quality, and cost of mask induction of anesthesia and laryngeal mask airway insertion or tracheal intubation were studied in young non-premedicated volunteers given high inspired concentrations of sevoflurane (6 to 7%). ⋯ The induction of anesthesia to loss of lid reflex in young non-premedicated adults approaches the speed of intravenous induction techniques. No untoward airway responses were noted during mask induction of anesthesia with a three-breath technique. In response to intubation, no adverse airway responses, including jaw tightness, laryngospasm, and excessive coughing or bucking, occurred in participants whose duration of mask administration of sevoflurane met the appropriate times (as determined in this study).
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Randomized Controlled Trial Multicenter Study Clinical Trial
Multicenter study of target-controlled infusion of propofol-sufentanil or sufentanil-midazolam for coronary artery bypass graft surgery. Multicenter Study of Perioperative Ischemia (McSPI) Research Group.
The use of target-controlled infusions of anesthetics for coronary artery bypass graft surgery has not been studied in detail. The effects of target-controlled infusions of propofol or sufentanil, supplemented by infusions of sufentanil or midazolam, respectively, were evaluated and compared. ⋯ Target-controlled infusions of propofol or sufentanil, supplemented by infusions of sufentanil or midazolam, respectively, were suitable to provide anesthesia for coronary artery bypass graft surgery. Continuous monitoring revealed a high prevalence of hemodynamic abnormalities. Despite greater hypotension in the propofol-sufentanil group and greater hypertension in the sufentanil-midazolam group, episodes of myocardial ischemia were similar for both groups and were not temporally related to episodes of hemodynamic abnormalities.
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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.