Anesthesia and analgesia
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Anesthesia and analgesia · Aug 1994
Changes in heart rate variability under propofol anesthesia: a possible explanation for propofol-induced bradycardia.
We propose to study the bradycardia associated with propofol anesthesia. Ten women undergoing laparoscopy for benign disease were studied using ambulatory electrocardiogram monitoring. Anesthesia was induced with an intravenous bolus of propofol and maintained with an infusion. ⋯ We conclude that high-frequency variability reflects parasympathetic tone. Propofol anesthesia reduces parasympathetic tone to a lesser degree than sympathetic tone. This autonomic milieu predisposes the patient to developing bradycardia in response to parasympathetic stimuli.
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Anesthesia and analgesia · Aug 1994
Determination of end-tidal sevoflurane concentration for tracheal intubation and minimum alveolar anesthetic concentration in adults.
The purpose of this study was to determine both the concentration of sevoflurane required for tracheal intubation (MACEI) and its minimum alveolar anesthetic concentration (MAC) in adults. The study group consisted of 86 elective surgical patients, ASA physical status I or II, aged 16-59 yr. There was no premedication administered. ⋯ The MAC of sevoflurane was 1.58% (95% confidence limits, 1.14%-1.98%), and the AD95 (anesthetic ED95) was 2.96%. The MACEI/MAC ratio was 2.86 (95% confidence limits, 2.63-3.43). Anesthesia induction followed by tracheal intubation can be accomplished in adults when sevoflurane is administered as a sole anesthetic, but in excess of 8% end-tidal concentration.
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Anesthesia and analgesia · Aug 1994
Isoflurane modulates phorbol myristate acetate-, prostaglandin D2-, and prostaglandin E2-induced alterations in hepatic flow and metabolism in the perfused liver in fasted rats.
Protein kinase C (PKC) is thought to play an important role in the regulation of hepatic flow and metabolism in the liver. The activation of PKC has been implicated in pathologic responses of the organisms to immunologically active substances including endotoxin. The effects of volatile anesthetics on the hemodynamic and metabolic alterations associated with PKC activation were studied using isolated liver perfusion. ⋯ A similar inhibition of the PMA-induced alterations was observed in the liver treated with halothane at 2%. Isoflurane attenuated the flow reduction and stabilized the oxygen consumption after the administration of prostaglandin D2 (PGD2) and E2 (PGE2), possible mediators of PMA. Isoflurane, and presumably other volatile anesthetics, may elicit beneficial effects on the liver by attenuating the PKC-mediated alterations in hepatic hemodynamics and metabolism when PKC in the liver is activated through pathologic mechanisms.
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Anesthesia and analgesia · Aug 1994
Randomized Controlled Trial Clinical TrialRecovery from outpatient laparoscopic tubal ligation is not improved by preoperative administration of ketorolac or ibuprofen.
The analgesic efficacy of a single dose of ketorolac or ibuprofen given preoperatively was assessed in healthy outpatients undergoing general anesthesia for laparoscopic tubal ligation. Fifty patients were randomized to receive either ketorolac 60 mg intravenously (i.v.), ibuprofen 800 mg orally, or placebo in a double-blind manner. Anesthesia was induced with fentanyl 2 micrograms/kg, thiopental 5 mg/kg, and either vecuronium 0.1 mg/kg or succinylcholine 1.5 mg/kg i.v. and was maintained with nitrous oxide 67% in oxygen and isoflurane. ⋯ The dose of parenteral morphine required in the PACU was not different between the control (7 +/- 1.2 mg), ibuprofen (5.7 +/- 1.4 mg), and ketorolac (6.1 +/- 1.4 mg) groups. There was no difference between groups in terms of pain visual analog scale (VAS) scores, fatigue VAS scores, recovery times, or the incidence of postoperative nausea and vomiting. The preoperative administration of either parenteral ketorolac or oral ibuprofen did not decrease postoperative pain or side effects when compared to placebo in this outpatient population.