Anesthesia and analgesia
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Anesthesia and analgesia · Oct 1992
Randomized Controlled Trial Comparative Study Clinical TrialA comparative study of 0.25% ropivacaine and 0.25% bupivacaine for brachial plexus block.
The present study compares the effectiveness of 0.25% ropivacaine and 0.25% bupivacaine in 44 patients receiving a subclavian perivascular brachial plexus block for upper extremity surgery. The patients were assigned to two equal groups in this randomized, double-blind study; one group received ropivacaine 0.25% (112.5 mg) and the other, bupivacaine 0.25% (112.5 mg), both without epinephrine. Onset times for analgesia and anesthesia in each of the C-5 through T-1 brachial plexus dermatomes did not differ significantly between the two groups. ⋯ The mean duration of analgesia ranged from 9.2 to 13.0 h, and the mean duration of anesthesia ranged from 5.0 to 10.2 h. Both groups required supplementation with peripheral nerve blocks or general anesthesia in a large number of cases, with 9 of the 22 patients in the bupivacaine group and 8 of the 22 patients in the ropivacaine group requiring supplementation to allow surgery to begin. In view of the frequent need for supplementation noted with both 0.25% ropivacaine and 0.25% bupivacaine, we do not recommend using the 0.25% concentrations of these local anesthetics to provide brachial plexus block.
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Anesthesia and analgesia · Oct 1992
Randomized Controlled Trial Clinical TrialEpidural clonidine enhances postoperative analgesia from a combined low-dose epidural bupivacaine and morphine regimen.
In a randomized, double-blind, placebo-controlled trial, the value of adding clonidine to a low-dose epidural regimen for postoperative pain treatment was assessed. Twenty-four patients scheduled for hysterectomy during combined thoracic epidural (bupivacaine and morphine) and general anesthesia were studied. Postoperative analgesia consisted of epidural bupivacaine (5 mg/h) and morphine (0.1 mg/h) for 12 h. ⋯ We found no significant difference in pain scores at rest between the clonidine and placebo groups but an enhanced analgesic effect by clonidine during cough and mobilization (P less than 0.05). Arterial blood pressure decreased significantly during clonidine infusion and remained lower than in the control group throughout the study. We conclude that a continuous low-dose epidural clonidine infusion enhances analgesia from a combined low-dose epidural bupivacaine and morphine regimen after hysterectomy; however, the concomitant decrease in arterial blood pressure during epidural clonidine deserves further study before such a regimen can be recommended.
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Anesthesia and analgesia · Oct 1992
Randomized Controlled Trial Comparative Study Clinical TrialComparative effects of ketorolac, dezocine, and fentanyl as adjuvants during outpatient anesthesia.
The comparative effects of ketorolac, dezocine, and fentanyl were evaluated in 136 healthy female patients undergoing outpatient laparoscopic procedures according to a randomized, double-blind protocol. Patients received ketorolac (60 mg) or dezocine (6 mg) or fentanyl (100 micrograms, control group) before the start of the operation. A standardized general anesthetic technique consisting of midazolam (2 mg), fentanyl (50 micrograms), and propofol (2 mg/kg) for induction of anesthesia followed by propofol (120 micrograms.kg-1.min-1), vecuronium (1-2 mg), and 67% nitrous oxide in oxygen for maintenance of anesthesia, was used. ⋯ However, 52% of the patients receiving dezocine required antinausea therapy in the postanesthesia care unit, compared with 20% and 18% in the fentanyl and ketorolac groups, respectively. Finally, recovery times were significantly shorter in the ketorolac (vs dezocine) group. Although both ketorolac and dezocine were effective alternatives to fentanyl when administered during outpatient laparoscopy, dezocine was associated with an increased incidence of postoperative nausea and a delayed discharge time compared with ketorolac.
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Desflurane causes dose-dependent decreases in cerebrovascular resistance and cerebral metabolic rate of oxygen consumption (CMRO2), suggesting that desflurane is a cerebral arteriolar dilator with global flow-metabolism coupling similar to halothane and isoflurane. Desflurane is also similar to isoflurane in that cerebrovascular responsivity to carbon dioxide appears to be maintained. In the dog, arterial hypotension to 40 mm Hg induced with 2.4 MAC desflurane resulted in global decreases in cerebral blood flow of 60% and CMRO2 of 20%. ⋯ The electroencephalographic effects of desflurane are similar to those of isoflurane in humans, and burst suppression is easily achieved. There are no data available concerning possible interactions between desflurane and the outcome of a cerebral ischemic event. Similar to other potent volatile agents, desflurane can cause cerebral vasodilation and may result in intracranial pressure changes in vulnerable patients, but if adequate hyperventilation and depth of anesthesia are maintained, it is probably safe to use desflurane in a manner similar to isoflurane in patients with decreased intracranial compliance.
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Anesthesia and analgesia · Oct 1992
Randomized Controlled Trial Clinical TrialVomiting after alfentanil anesthesia: effect of dosing method.
This double-blind study correlated the association of nausea and vomiting after alfentanil with its method of administration (bolus dose vs continuous infusion). Of 40 women undergoing lower abdominal gynecologic or laparoscopic surgery, 20 received an intravenous alfentanil (30 micrograms/kg) bolus dose for induction of anesthesia, with subsequent bolus doses of 10 micrograms/kg every 10 min, and 20 received the same induction dose delivered over 1 min, followed by an intravenous infusion at 1.0 micrograms.kg-1.min-1. ⋯ Laparoscopy and alfentanil infusion combined synergistically to worsen the incidence of nausea and vomiting. We conclude that alfentanil infusion for laparoscopic surgery entails a high risk for nausea and vomiting.