Anesthesia and analgesia
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Anesthesia and analgesia · Aug 1996
Randomized Controlled Trial Comparative Study Clinical TrialMechanism of action of an epidural top-up in combined spinal epidural anesthesia.
The purpose of this study was to elucidate the mechanism of action by which an epidural top-up reinforces anesthesia in combined spinal epidural anesthesia. Thirty patients scheduled to undergo lower limb orthopedic surgery were randomly allocated to three groups of 10 patients each. In all patients, a 16-gauge Tuohy needle was introduced into the epidural space. ⋯ In Group 3 there was a nonsignificant increase of 0.3 +/- 0.5 segments. Intergroup comparisons showed that this increase in Group 1 was significant compared with those in Groups 2 and 3, and that the increase in Group 2 was significant compared with that in Group 3. We conclude that the mechanism of action by which an epidural top-up reinforces anesthesia in combined spinal epidural anesthesia can be explained partly by an epidural volume effect and partly by an effect of the local anesthetic itself.
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Anesthesia and analgesia · Aug 1996
Randomized Controlled Trial Comparative Study Clinical TrialIntracranial pressure and hemodynamic effects of remifentanil versus alfentanil in patients undergoing supratentorial craniotomy.
Remifentanil hydrochloride is an ultra-short-acting esterase metabolized mu-opioid receptor agonist. The purpose of this study was to provide preliminary information regarding the effects of this drug on intracranial pressure (ICP) and mean arterial pressure (MAP) in patients scheduled for craniotomy. Twenty-six patients undergoing excision of supratentorial space-occupying lesions were anesthetized with 0.3-0.8 vol% isoflurane in a 2:1 mixture of nitrous oxide:oxygen. ⋯ Both drugs were associated with a dose-dependent decrease in MAP. Remifentanil was 31 times more potent than alfentanil for effects on MAP. We conclude that remifentanil produces similar cerebral perfusion pressure effects as does alfentanil.
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Anesthesia and analgesia · Aug 1996
Randomized Controlled Trial Comparative Study Clinical TrialA comparison of costs and efficacy of ondansetron and droperidol as prophylactic antiemetic therapy for elective outpatient gynecologic procedures.
Ondansetron and droperidol are both effective prophylactic antiemetics for gynecologic outpatient procedures. However, increased drowsiness, delayed discharge, and postdischarge restlessness may occur with droperidol, and ondansetron is costly. In this prospective, randomized, double-blind, placebo-controlled study involving 161 women, we compared the efficacy, safety, and cost-effectiveness of ondansetron (4 mg intravenously [i.v.] with droperidol (0.65 mg or 1.25 mg i.v.) in the prevention of postoperative nausea and vomiting (PONV) after outpatient gynecologic surgery. ⋯ The incidence of PONV in the hospital and after discharge, the need for rescue antiemetic therapy, and recovery and discharge times were similar for the ondansetron and both droperidol groups but differed significantly from those for the placebo group. The cost-effectiveness ratios for both droperidol 0.65 mg and 1.25 mg groups were significantly lower than those for the ondansetron and placebo groups. We conclude that droperidol 0.625 mg i.v. provides antiemetic prophylaxis comparable to that of ondansetron 4 mg i.v. without increasing side effects or delaying discharge and is most cost-effective.
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Anesthesia and analgesia · Aug 1996
Randomized Controlled Trial Comparative Study Clinical TrialEffects of ondansetron on emesis in the first 24 hours after craniotomy in children.
Children undergoing neurosurgical resection are at high risk for postoperative nausea and vomiting. Ondansetron, a selective serotonergic (5-HT3) antagonist, is effective in reducing postoperative vomiting in several high-risk populations. In a prospective, randomized study, we compared the prophylactic use of intravenous ondansetron, 0.15 mg/kg, versus placebo for the prevention of emesis in 60 children, aged 2-18 yr, undergoing craniotomies for resective procedures. ⋯ For the entire 24-h interval, the incidence of emesis in children who received ondansetron (57%) was not significantly different from that in those who received placebo (66%); however, in the first 8 h, the incidence was 25% (ondansetron) vs 44% (placebo) (P = not significant). In those receiving placebo, there was no difference in emesis between patients undergoing operations above versus below the tentorium. Although our sample size was too small to completely exclude any beneficial effect, ondansetron appears ineffective in preventing postoperative emesis in this patient population.
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Anesthesia and analgesia · Aug 1996
Randomized Controlled Trial Clinical TrialThe effects of varying volumes of crystalloid administration before cesarean delivery on maternal hemodynamics and colloid osmotic pressure.
The value of intravenous crystalloid administration in preventing spinal-induced hypotension in the parturient has recently been questioned. Also, the association between increasing crystalloid volume and decreasing postpartum colloid osmotic pressure (COP) raises concern regarding the risk of maternal and fetal pulmonary edema. To study the dose-response effect of varying amounts of crystalloid volume prior to spinal anesthesia, we measured maternal hemodynamic variables and maternal and fetal COP in three groups of healthy parturients receiving spinal anesthesia for elective cesarean delivery. ⋯ Total ephedrine and additional intravenous (i.v.) fluid administered did not differ among groups. The 20- and 30- mL/kg groups showed a larger decline in maternal COP than the 10-mL/kg group; no differences in neonatal COP were seen with varying preload. We conclude that increasing the amount of i.v. crystalloid administered to 30 mL/kg in the healthy parturient does not significantly alter maternal hemodynamics or ephedrine requirements after spinal anesthesia and has no apparent benefit.