Anesthesia and analgesia
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Anesthesia and analgesia · Aug 1991
Effects of dexmedetomidine, a novel imidazole sedative-anesthetic agent, on adrenal steroidogenesis: in vivo and in vitro studies.
Inhibition of steroidogenesis may be produced perioperatively by imidazole compounds, such as the hypnotic agent etomidate, with potentially serious consequences for patient morbidity and mortality. Dexmedetomidine, ([+]4-[1-[2,3-dimethylphenyl]-ethyl]-1H-imidazole), another imidazole compound with anesthetic like properties, is now being used perioperatively. Therefore, we investigated the effects of dexmedetomidine on steroidogenesis as well as on binding to glucocorticoid receptors in a series of in vitro and in vivo animal studies. ⋯ At dexmedetomidine concentrations greater than 10(-7) M, a dose-dependent inhibition of corticosterone release was detected in response to ACTH stimulation in vitro. At these high dexmedetomidine concentrations, [3H]dexamethasone binding was not affected. In the in vivo dog experiments, basal cortisol levels decreased and the cortisol response to ACTH was blunted 3 h after dexmedetomidine administration.(ABSTRACT TRUNCATED AT 250 WORDS)
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Anesthesia and analgesia · Aug 1991
Randomized Controlled Trial Comparative Study Clinical TrialEffect of intravenously administered dexmedetomidine on pain after laparoscopic tubal ligation.
Ninety-six women undergoing laparoscopic tubal ligation were randomized to receive intravenously either 0.2 or 0.4 microgram/kg of dexmedetomidine, 60 micrograms/kg of oxycodone, or 250 micrograms/kg of diclofenac for postoperative pain in a double-blind study design. The study drugs were administered in the recovery room for moderate or severe pain and were repeated until pain subsided or disappeared. In the group receiving diclofenac, 83% of the patients required analgesic supplementation with morphine. ⋯ Both doses of dexmedetomidine decreased heart rate when compared with diclofenac (P less than 0.001). In the group given 0.4 microgram/kg of dexmedetomidine, 33% of the patients required atropine for bradycardia. The authors conclude that after laparoscopic tubal ligation, intravenously administered dexmedetomidine relieves pain and reduces opioid drug requirement but is attended by sedation and a high incidence of bradycardia.
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Anesthesia and analgesia · Aug 1991
Clinical Trial Controlled Clinical TrialEffect of prior anesthetic solution on epidural morphine analgesia.
The quality and duration of analgesia and incidence of side effects following epidurally administered morphine after cesarean section are highly variable. Two suggested sources of this variability are prior use of epinephrine-containing solutions, which may enhance both analgesia and side effects of morphine, and prior use of 2-chloroprocaine, which may inhibit epidural morphine analgesia. To examine these proposed sources of this variability we performed two studies. ⋯ In the second study, designed to test the effect of 2-chloroprocaine, 30 women received 7 mL of either 2% 2-chloroprocaine or lidocaine for epidural catheter testing, followed by 0.5% bupivacaine for epidural anesthesia. Compared to lidocaine testing, 2-chloroprocaine decreased the duration of epidural morphine analgesia (median 16 h with 2-chloroprocaine vs 24 h with lidocaine; P less than 0.05) without altering the incidence of side effects. The authors conclude that addition of epinephrine to local anesthetic does not increase the incidence of side effects or the analgesic effect from epidurally administered morphine. 2-Chloroprocaine, even when administered in small doses remote to the time of morphine injection, interferes with the duration of epidural morphine analgesia.
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Anesthesia and analgesia · Aug 1991
Comparative StudyComparison of continuous epidural bupivacaine infusion plus either continuous epidural infusion or patient-controlled epidural injection of fentanyl for postoperative analgesia.
We compared the postoperative epidural analgesia provided by the continuous epidural infusion of bupivacaine supplemented with patient-controlled injection (PCA) of epidural fentanyl with that provided by a continuous infusion of bupivacaine supplemented with a continuous epidural infusion of fentanyl. Our patient population comprised 16 ASA physical status I or II patients undergoing laparotomy with a midline incision under general anesthesia combined with bupivacaine epidural analgesia. Post-operatively, a continuous epidural infusion of bupivacaine (0.1 mg.kg-1.h-1) was combined with epidural fentanyl given by either (a) PCA (15-micrograms bolus with a lockout interval of 12 min, n = 8) or (b) continuous infusion (1 microgram.kg-1.h-1, n = 8). ⋯ The dose of fentanyl given during each 4-h interval ranged between 40 and 160 micrograms in the PCA group and 251 and 292 micrograms in the continuous infusion group. Clinically detectable respiratory depression was not observed in either group. In conclusion, epidural administration of 0.1 mg.kg-1.h-1 bupivacaine combined with fentanyl provides effective postoperative analgesia with a total dose of fentanyl required that is lower when fentanyl is administered by epidural PCA rather than by continuous epidural infusion.