Anesthesia and analgesia
-
Anesthesia and analgesia · Oct 1992
Randomized Controlled Trial Clinical TrialLack of interaction between propofol and vecuronium.
We estimated the potency of vecuronium and measured the onset and duration of its action during total intravenous anesthesia with propofol to examine the possibility of any interaction between these two drugs. Propofol infusion was administered according to a three-step dosage scheme, and neuromuscular block was monitored by measuring the force of contraction of the adductor pollicis muscle after single-twitch stimulation of the ulnar nerve at 0.1 Hz. A control group of patients were similarly studied during anesthesia with thiopental, nitrous oxide, oxygen, and fentanyl. ⋯ The onset of action of an 80-micrograms/kg dose (2 x ED95) of vecuronium was 3.6 +/- 1.2 and 4.1 +/- 1.7 min (mean +/- SD), in the propofol (n = 10) and control (n = 10) groups, respectively. The respective times to recovery of the twitch height to 25% of control and the recovery indices (25%-75% recovery of twitch height) in the propofol versus control groups were 28.3 +/- 6.6 and 28.0 +/- 1.7 min and 13.3 +/- 6.8 and 15.4 +/- 11.9 min, respectively. There were no significant differences in any of the measured variables between the propofol and control groups, indicating the lack of any interaction between propofol and vecuronium.
-
The low solubility of desflurane contributes to rapid emergence after outpatient anesthesia. Compared with isoflurane, recovery times to eye opening, response to verbal commands, and orientation to person, place, and time have been significantly shorter. Even when compared with the rapid, short-acting intravenous anesthetic propofol for induction and maintenance of outpatient anesthesia, desflurane displayed more favorable early recovery characteristics. ⋯ As desflurane is pungent and possesses respiratory irritant properties, propofol will likely remain the induction agent of choice in the outpatient setting. In conclusion, desflurane appears to have few adverse effects on recovery after ambulatory surgery, but nausea and emesis were lower with propofol. Desflurane's relative ease of administration versus propofol may be an important determinant of its future role in outpatient anesthesia.
-
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.
-
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.