Anesthesia and analgesia
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The pharmacokinetics of fentanyl were studied in fourteen neonates undergoing major surgical procedures. Five patients were less than 1 day of age, seven were 1-4 days old, and two were 7-14 days old. Fentanyl was given intravenously, 10 micrograms/kg (n = 1), 25 micrograms/kg (n = 4), or 50 micrograms/kg (n = 9), and plasma concentrations measured at intervals of up to 18 hr. ⋯ In seven patients transient rebound in plasma fentanyl concentrations of 0.5 ng/ml or greater occurred. In three patients with markedly increased intraabdominal pressure, the t 1/2 beta was 1.5-3 times the population mean. Thus fentanyl disposition in neonates is highly variable, but the t 1/2 beta is predictably prolonged in the presence of increased abdominal pressure.
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Anesthesia and analgesia · Mar 1986
Comparative StudyA comparison of morphine, fentanyl, and sufentanil anesthesia for cardiac surgery: induction, emergence, and extubation.
We compared anesthetic doses of three popular opiates, morphine (n = 10), fentanyl (n = 9), and sufentanil (n = 9) in patients undergoing cardiac surgery. Opiate administration after induction was based upon EEG and cardiovascular signs of the depth of anesthesia. ⋯ The following times (mean and SEM) were significantly (P less than 0.05) shorter for sufentanil than for fentanyl or morphine: induction (15 +/- 2.3 min, 5.9 +/- 0.7 min, and 3.0 +/- 0.2 min for morphine, fentanyl, and sufentanil, respectively); return of consciousness (morphine 109.7 +/- 34.4 min, fentanyl 62.3 +/- 17.9 min, sufentanil 17 +/- 8.7 min); return of acceptable and stable cardiovascular status (morphine 587.3 +/- 139.3 min, fentanyl 537.9 +/- 144.8 min, sufentanil 173.7 +/- 56.8 min); and extubation (morphine 1121.3 +/- 61.8 min, fentanyl 1005.7 +/- 77.7 min, sufentanil 533.3 +/- 67.8 min). We conclude that sufentanil administered in the dosage range of 19 micrograms/kg allows more rapid induction, earlier emergence from anesthesia, and faster extubation of patients than either morphine or fentanyl.
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Anesthesia and analgesia · Feb 1986
Comparative StudyA comparison of the effects of alfentanil applied to the spinal cord and intravenous alfentanil on noxiously evoked activity of dorsal horn neurons in the cat spinal cord.
The purpose of this study was to examine the effects of alfentanil applied to the surface of the spinal cord and the effects of intravenously administered alfentanil on noxiously evoked activity of dorsal horn neurons. Extracellular single neuron recordings were obtained from wide dynamic range neurons in 26 decerebrate cats with transected spinal cords. Spinally administered alfentanil, 25 micrograms or 50 micrograms, caused 36 and 86% suppression of noxiously evoked activity, respectively. ⋯ Intravenously administered alfentanil, 12.5 micrograms/kg or 25 micrograms/kg, produced suppression of 43 and 89%, respectively, with maximum mean suppression observed at the 6- and 3-min time points, respectively. Complete recovery after intravenous administration was seen within 30 min. This study, using a sensitive neurophysiologic assay, demonstrates the important differences in onset and duration of drug effects that must be considered when comparing the responses of spinal cord neurons to intravenously administered narcotics and narcotics applied directly to the surface of the spinal cord.
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Halothane or isoflurane was used to induce anesthesia in children scheduled for outpatient surgical procedures. Both agents were administered at predetermined rates until comparable concentrations in end-expired air were reached. Induction of anesthesia, as well as the time taken before tracheal intubation was possible, was protracted in patients given isoflurane. In the recovery period, the times taken to respond to pharyngeal suction, to tracheal extubation, and to the first cry were similar for both anesthetic agents.
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Anesthesia and analgesia · Feb 1986
Does intravenous infusion of nitroglycerin potentiate pancuronium- and vecuronium-induced neuromuscular blockade?
The dose requirement for 95% depression of twitch tension and the time course of the neuromuscular blocking effects of the ED95 of pancuronium bromide and vecuronium bromide were studied during intravenous infusion of glucose, 5%, and nitroglycerin, 1 microgram X kg-1 X min-1, in 20 cats anesthetized with pentobarbital. Nitroglycerin administered continuously starting 1 hr before the administration of the ED95 and maintained during at least five maintenance doses of either pancuronium or vecuronium did not significantly potentiate the action of the neuromuscular blocking drugs, nor did it alter their time course of action. A tendency for a decrease (statistically not significant) rather than an increase in the duration of action of maintenance doses of both pancuronium and vecuronium was apparent during the treatment with nitroglycerin. These findings indicate a lack of interaction between pancuronium or vecuronium and nitroglycerin, provided that moderate doses are used.