Anesthesia and analgesia
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Anesthesia and analgesia · Aug 1984
Continuous epidural infusion of morphine for treatment of pain after thoracic surgery: a new technique.
We evaluated postoperative pain relief and the incidence of side effects of three methods of thoracic epidural analgesia. Ninety patients, divided into three equal groups, received postoperative analgesia after thoracic surgery either as intermittent epidural injections of bupivacaine (25 mg/5 ml, 0.5% solution) as needed, or, intermittent epidural injections of morphine (5 mg/5 ml of normal saline, 0.1% solution) as needed, or continuous epidural infusion of morphine (0.1 mg, in 1 ml of normal saline) per hour supplemented with intravenous morphine (2 mg) upon request. Pain relief was evaluated by each patient on a pain scale visual analogue and by pain relief questionnaire for a period of 72 hr. ⋯ Intermittent epidural injection of morphine relieved pain for 5.8 +/- 2.3 hr/injection and was associated with urinary retention in all patients, with pruritus in 12 patients, and with central narcosis and respiratory depression in 8 patients. Continuous epidural infusion of morphine with occasional intravenous morphine (2 mg) supplementation also effectively relieved postoperative pain and was associated with minimal systemic side effects. One patient complained of pruritus, and two patients developed urinary retention.(ABSTRACT TRUNCATED AT 250 WORDS)
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Anesthesia and analgesia · Aug 1984
Comparative StudyContrasting effects of halothane, isoflurane, and enflurane on in vivo drug metabolism in the rat.
Inhalational anesthetics might affect perioperative drug elimination by alterations in distribution, hepatic blood flow, or metabolism. The purpose of our study was to investigate the effects of inhalational anesthetics on drug metabolism in vivo during the pre- and postanesthetic periods. The aminopyrine breath test was used as a sensitive non-invasive index of drug metabolism, when the rate of elimination of 14CO2 in the exhaled breath of rats was measured after the intravenous administration of (N-dimethyl-14C) aminopyrine. ⋯ Although isoflurane (1.3%) caused a slight prolongation (P less than 0.05) of aminopyrine half-life 2 hr after anesthesia, this effect had disappeared by 24 hr. Enflurane (1.8%) did not affect aminopyrine elimination. Our results imply that volatile anesthetics may reduce the elimination of drugs given in the perioperative period and that differences may exist among anesthetic agents.