Anesthesia and analgesia
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Anesthesia and analgesia · Jul 1995
Randomized Controlled Trial Comparative Study Clinical TrialThe effect of N-methyl-D-aspartate antagonist (ketamine) on single and repeated nociceptive stimuli: a placebo-controlled experimental human study.
Ketamine is a noncompetitive N-methyl-D-aspartate (NMDA) receptor channel blocker known to inhibit "wind-up" and hence central hyperexcitability of dorsal horn neurons. We sought to assess the effect of ketamine on single and repeated nociceptive stimuli. A placebo-controlled, human (12 volunteers) experimental study was conducted in which several psychophysical (pain detection and tolerance thresholds, magnitude ratings) and electrophysiologic (withdrawal reflex) techniques were used 1) to investigate whether a ketamine (0.5 mg/kg) bolus followed by a 20-min infusion (9 micrograms.kg-1.min-1) inhibits central temporal summation to repeated nociceptive electrical stimuli, and 2) to assess quantitatively the hypoalgesic potency using several experimental nociceptive stimuli (argon laser, pressure, electrical). ⋯ The pressure pain detection and tolerance thresholds were increased significantly by ketamine, whereas the laser heat pain and tolerance thresholds remained stable compared with placebo. The stimulus response function showed that ketamine reduced the responses to the highest electrical stimulus intensities (1.4, 1.6, and 1.8 times the reflex threshold). We conclude that ketamine inhibits central temporal summation in humans and has a marked hypoalgesic effect on high intensity nociceptive stimuli.
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Anesthesia and analgesia · Jul 1995
Randomized Controlled Trial Clinical TrialThe efficacy of prophylactic ondansetron, droperidol, perphenazine, and metoclopramide in the prevention of nausea and vomiting after major gynecologic surgery.
The prophylactic antiemetic efficacy of intravenous (i.v.) ondansetron, droperidol, perphenazine, and metoclopramide was evaluated in a prospective, double-blind study of 360 ASA physical status I-III patients undergoing total abdominal hysterectomy (TAH). Subjects were randomized to receive i.v., one of ondansetron 4 mg, droperidol 1.25 mg, perphenazine 5 mg, metoclopramide 10 mg, or placebo prior to induction of anesthesia. Hypotension immediately after administration of metoclopramide was observed in two patients and four patients given ondansetron developed profound systolic hypotension at induction of anesthesia. ⋯ Metoclopramide was ineffective. Although ondansetron, droperidol, and perphenazine were effective in providing antiemetic prophylaxis, only i.v. perphenazine was free of side effects. Hence, we conclude that perphenazine is the best choice for antiemetic prophylaxis after TAH.
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Anesthesia and analgesia · Jul 1995
Randomized Controlled Trial Comparative Study Clinical TrialUse of sevoflurane during elective cesarean birth: a comparison with isoflurane and spinal anesthesia.
This randomized study compared sevoflurane 1% and isoflurane 0.5% in terms of maternal and neonatal outcomes. In addition, neonatal outcome in both groups was compared with a cohort of patients delivered by cesarean birth using spinal anesthesia. Fifty-five patients presenting for elective cesarean birth under general anesthesia were randomly assigned to receive either sevoflurane 1% or isoflurane 0.5% in a 50% nitrous oxide and oxygen mixture for maintenance. ⋯ Similarly, the level of postoperative comfort was the same in both groups. Comparing the general and the spinal anesthetic groups, no differences could be detected in neonatal outcome. Fluoride concentrations were modestly increased above preoperative levels in maternal and umbilical blood samples after sevoflurane administration.(ABSTRACT TRUNCATED AT 250 WORDS)
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Anesthesia and analgesia · Jul 1995
Randomized Controlled Trial Clinical TrialIntravenous ketorolac tromethamine does not worsen platelet function during knee arthroscopy under general anesthesia.
Ketorolac (KT) prolongs bleeding time and inhibits platelet aggregation and platelet thromboxane production in healthy, awake volunteers. However, platelet function may be accentuated during the stress of general anesthesia (GA) and surgery. The purpose of this study was to investigate platelet function changes during a standard GA technique and surgery, as well as after a single intraoperative dose of intravenous (i.v.) KT. ⋯ Platelet function appears to be accentuated during GA and surgery as evaluated by BT in the placebo group. Further, platelet function by BT, PA, and TEG was not inhibited after i.v. KT despite near complete abolition of TxB2 production.
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Anesthesia and analgesia · Jul 1995
Randomized Controlled Trial Clinical TrialThe effects of milrinone on platelets in patients undergoing cardiac surgery.
Although amrinone produces thrombocytopenia, no information is available regarding the acute effects of milrinone on platelets. Therefore, we evaluated the effects of milrinone on platelet number and function in cardiac surgical patients. Twenty-seven patients were studied during cardiac surgery requiring cardiopulmonary bypass (CPB). ⋯ In both groups, platelet counts decreased significantly from the baseline at 2 and 24 h after CPB, and bleeding time increased significantly from the baseline at 2 and 24 h after CPB. No significant thromboelastoplasty (TEG) changes were observed in either group, and there were no significant differences in platelet aggregation or chest tube drainage between the groups. Acute milrinone administration did not cause significant changes in platelet number or function in patients undergoing cardiac operations requiring CPB, beyond the usual adverse effects of cardiac surgery and CPB.