Anesthesia and analgesia
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Anesthesia and analgesia · Aug 1992
Effects of hypocarbia on the pharmacodynamics of sufentanil in humans.
Descriptors of power and frequency derived from power spectral analysis of the electroencephalogram (EEG) were used to determine the effects of low-dose sufentanil (0.1 micrograms/kg) on brain activity. The effects of hypocarbia alone and of hypocarbia with sufentanil in patients receiving a N2/O2 (70%:30%) anesthetic were also studied. ⋯ When the anterior EEG montages from the two groups that received sufentanil were compared, the delta power band, spectral edge 50 (median power frequency), and the relative power in the delta power band divided by the alpha plus beta power bands [D/(A + B)] in the hypocarbic group exhibited a significantly greater shift of power into the lower frequency range. It is concluded that (a) power spectral analysis is a sensitive measure of the effects of hypocarbia and small doses of sufentanil on the brain; (b) the power spectral analysis descriptors--delta power band, spectral edge 50, and [D/(A + B)]--are statistically the most sensitive to EEG changes induced by sufentanil; and (c) hypocarbia intensifies patient EEG response to sufentanil, as judged by changes in EEG descriptors.
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Anesthesia and analgesia · Aug 1992
Modification of a new catheter for air retrieval and resuscitation from lethal venous air embolism: effect of nitrous oxide on air retrieval.
A modification of a new Arrow prototype catheter was evaluated for its ability to retrieve venous air emboli and for its effect on the success rate of resuscitation from venous air emboli in dogs anesthetized with isoflurane and nitrous oxide (66%) in oxygen. In an additional group of dogs, nitrogen was substituted for nitrous oxide in the inspired gases to determine whether the presence of nitrous oxide (as traditionally used in this model of lethal venous air emboli) increased the apparent amount of gas retrieval or altered the success rate of resuscitation. Dogs were placed in the seated position with the head 90 degrees to the horizontal. ⋯ Attempts to aspirate venous air emboli were begun with the first decrease in expired CO2. The amounts of gas retrieved, expressed as a percent of the injected air, and the incidence of successful resuscitation were compared between groups. In both treatment groups (nitrous oxide and nitrogen), the percent of injected venous air retrieved (73% +/- 13% and 65% +/- 21%, mean value +/- SD, respectively) and success rate of resuscitation (four of six dogs in each group) were significantly increased compared with the control group in which no attempt was made to retrieve injected venous air, and none of the six dogs survived.(ABSTRACT TRUNCATED AT 250 WORDS)
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Anesthesia and analgesia · Aug 1992
Randomized Controlled Trial Comparative Study Clinical TrialEffects on biliary tract pressure in humans of intravenous ketorolac tromethamine compared with morphine and placebo.
This study compared the effect of ketorolac tromethamine with that of morphine and placebo on biliary tract pressure. Intraoperatively, 31 anesthetized patients received either ketorolac (30 mg IV, n = 16) or morphine (5 mg IV, n = 15) after a cholecystectomy or gallstone removal. Intrabiliary tract pressure was measured 5 min after dosing. ⋯ In the morphine group, there was significant increase in pressure over baseline. Postoperatively, there was no significant difference between ketorolac and placebo. We conclude that ketorolac has little or no effect on biliary tract dynamics; therefore, ketorolac may be a logical choice for analgesia in those situations in which spasm of the biliary tract is undesirable.
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Anesthesia and analgesia · Aug 1992
Randomized Controlled Trial Clinical TrialEffects of ketorolac and bupivacaine on recovery after outpatient arthroscopy.
The effects of intraarticular bupivacaine, systemic ketorolac, and a combination of both treatments on postoperative pain and mobilization were evaluated in 60 healthy outpatients undergoing arthroscopic knee surgery under general anesthesia. After induction of anesthesia, patients received 2 mL of either ketorolac (60 mg) or saline solution (1 mL IV and 1 mL IM). On completion of surgery, the patient's knee joint was injected with 30 mL of either 0.5% bupivacaine or saline solution, according to a randomized, double-blind protocol. ⋯ Similarly, there were no differences in the times to ambulation or discharge or in analgesic requirements at home. In conclusion, a combination of systemic ketorolac and intraarticular bupivacaine decreased analgesic requirements and pain on awakening after arthroscopic surgery. However, the use of ketorolac alone or in combination with bupivacaine offered no advantage over bupivacaine alone with respect to recovery times after outpatient arthroscopy.