Anesthesia and analgesia
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Anesthesia and analgesia · Jul 1986
Intrathecal morphine and heroin in humans: six-hour drug levels in spinal fluid and plasma.
Lumbar spinal fluid and plasma concentrations of morphine were measured by radioimmunoassay after intrathecal administration of 1 mg of morphine (n = 13) or heroin (n = 10). Plasma levels of morphine were measured regardless of 'whether heroin or morphine was injected intrathecally, because of the rapid biotransformation of heroin to morphine in plasma. Significant drug concentrations appeared in plasma after intrathecal heroin (peak concentration 47.8 +/- 9.0 nmol/L, time to peak concentration 10 +/- 2.4 min); after intrathecal morphine plasma drug concentrations were significantly lower (8.1 +/- 1.0 nmol/L; P less than 0.002) and significantly later (216 +/- 39 min; P less than 0.002). Elimination half-life of heroin from spinal fluid (43 +/- 5 min) was significantly shorter than for morphine (73 +/- 5 min; P less than 0.02).
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Anesthesia and analgesia · Jul 1986
Wakefulness during cesarean section after anesthetic induction with ketamine, thiopental, or ketamine and thiopental combined.
Thirty-six pregnant women (ASA class I or II) at term who underwent general anesthesia and cesarean section received either ketamine, 1 mg/kg (n = 12); thiopental, 4 mg/kg (n = 13); or a combination of ketamine, 0.5 mg/kg, and thiopental, 2 mg/kg (n = 11). A blood pressure cuff inflated to 250 mm Hg isolated one arm from the effects of succinylcholine so that awareness during anesthesia could be assessed by asking the patient to move her hand. Although only one patient receiving ketamine responded to commands during anesthesia, 46% of patients receiving either thiopental or the combination responded to commands intraoperatively. ⋯ Three patients (8%) had postoperative recall of intraoperative awareness; one had received thiopental and two the combination. Maternal intraoperative cardiovascular responses among the groups were similar, as were umbilical blood gas values, newborn Apgar scores, and neonatal neurobehavioral test scores at 4 and 24 hr. Ketamine more effectively blocked maternal responsiveness to commands and strong stimuli during the first few minutes after anesthetic induction for cesarean section than did thiopental or a combination of thiopental and ketamine, each at a lower dose.
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Anesthesia and analgesia · Jun 1986
Randomized Controlled Trial Clinical TrialRoles of fentanyl and nitroglycerin in prevention of myocardial ischemia associated with laryngoscopy and tracheal intubation in patients undergoing operations of short duration.
The purpose of this study was to evaluate intravenous nitroglycerin given during induction of anesthesia as a means for prevention of myocardial ischemia and hemodynamic changes associated with induction, laryngoscopy, and intubation, in patients with stable angina scheduled for vascular operations of moderate duration. Forty-six patients were randomly assigned to receive either fentanyl, 3 micrograms/kg (group 1, n = 6), fentanyl, 8 micrograms/kg (group 2, n = 20), or fentanyl 3 micrograms/kg plus a continuous intravenous nitroglycerin infusion, 0.9 microgram X kg-1 X min-1 (group 3, n = 20), in addition to thiopental-pancuronium anesthetic induction, prior to laryngoscopy and intubation. The criteria for recognizing myocardial ischemia were the following: horizontal or downsloping ST segment depression equal to or greater than 1 mV, and/or ventricular arrhythmia, on CM5 recording. ⋯ Despite greater stability in MBP and heart rate in group 2, myocardial ischemia still occurred in four patients (not significantly different from group 1). Nitroglycerin added to low-dose fentanyl (group 3) produced significant reduction in myocardial ischemia (1/20) when compared with group 1 (P less than 0.01), and significantly greater stability in PCWP during laryngoscopy and intubation in comparison to groups 1 and 2. In patients with stable angina undergoing operations of short duration, the use of nitroglycerin infusion and low-dose fentanyl significantly decreases the incidence of myocardial ischemia associated with induction of anesthesia and tracheal intubation.