Anesthesia and analgesia
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Anesthesia and analgesia · Apr 1987
Randomized Controlled Trial Clinical TrialA randomized prospective controlled study of the metabolism and hepatotoxicity of halothane in humans.
In a randomized prospective controlled study in humans, the metabolism and hepatic effects of a single administration of halothane were compared with enflurane and meperidine. Pre- and postoperative antipyrine pharmacokinetics, intraoperative indocyanine green clearance, liver histology, and postoperative liver function tests were determined in 24 patients undergoing abdominal surgery who were randomly allocated to receive either halothane (0.5%, group I), enflurane (0.8%, group II), or meperidine (group III) as a supplement to a common basal anesthetic regimen consisting of thiopental, nitrous oxide/oxygen/muscle relaxant. In addition, end-tidal concentrations of the volatile reductive metabolites of halothane, chlorodifluoroethylene (CDF), and chlorotrifluoroethane (CTF) were determined in group I patients and serum and urinary inorganic fluoride were determined in both group I and II patients. ⋯ There were no significant differences in liver cell morphology (P greater than 0.5) in biopsies taken at the end of stage IV compared with biopsies at the end of stage III, from groups I and II. The results of this study show that reductive metabolism of halothane occurs routinely in patients undergoing halothane anesthesia under conditions of normoxia. This may be the cause of the changes in antipyrine clearance after halothane anesthesia.
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The respiratory effects of sevoflurane were studied in seven patients and compared with values obtained in another seven patients anesthetized with halothane. Resting ventilation, resting PaCO2, and ventilatory response to CO2 were measured awake and at 1.1 and 1.4 MAC levels of both anesthetic agents. ⋯ At 1.1 MAC, sevoflurane produced almost the same degree of respiratory depression as halothane. At 1.4 MAC, sevoflurane produced more profound respiratory depression than halothane.
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Anesthesia and analgesia · Feb 1987
Randomized Controlled Trial Clinical TrialHemodynamic effects of esmolol in chronically beta-blocked patients undergoing aortocoronary bypass surgery.
The hemodynamic effects of esmolol were studied in 40 patients scheduled for elective coronary artery surgery to determine whether the administration of esmolol in chronically beta-blocked patients would result in additional attenuation of sympathetically mediated hemodynamic stress responses to noxious stimuli. Patients were randomly assigned to receive IV infusions of esmolol or 5% dextrose in water (D5W). All received their regular dose of beta-adrenergic blocker within 6 hr of surgery and were anesthetized with diazepam, pancuronium, and enflurane. ⋯ However the incidence and magnitude of SNP use in the control group was significantly (P less than 0.05) greater. Thus, the lower blood pressure, in the absence of changes in systemic vascular resistance, cardiac index, heart rate, and pulmonary capillary wedge pressure points toward a decrease in myocardial contractility, suggesting that the addition of esmolol to chronically used beta-blockers resulted in an additional negative inotropic effect. We conclude that in patients with coronary artery disease in whom chronic beta-blocker therapy is continued until the time of surgery, esmolol does not further attenuate the heart rate response but does attenuate the increase in blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)
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Anesthesia and analgesia · Feb 1987
Low-dose enflurane as adjunct to high-dose fentanyl in patients undergoing coronary artery surgery: stable hemodynamics and maintained myocardial oxygen balance.
The effects of enflurane (end-tidal concentration 0.7%) on central and coronary hemodynamics and myocardial oxygenation were studied during steady state, high-dose fentanyl anesthesia in ten patients undergoing coronary artery bypass grafting operations. Compared with the response in ten patients receiving the same fentanyl anesthesia (100 micrograms/kg) without enflurane supplementation, enflurane caused a moderate reduction in mean arterial pressure, systemic vascular resistance, and left ventricular stroke work index. No patient showed signs of myocardial ischemia, and mean coronary sinus flow and calculated coronary resistance remained unchanged. ⋯ Myocardial oxygen extraction decreased in the enflurane supplemented group although it increased in the fentanyl group after surgical stimulation. Three fentanyl group patients and one enflurane-fentanyl group patient had a low myocardial lactate extraction as a sign of myocardial ischemia during surgery. We conclude that a 0.7% enflurane supplementation of 100 micrograms/kg fentanyl anesthesia does not endanger myocardial oxygenation and effectively prevents central and coronary hemodynamic responses to skin incision and sternotomy in patients undergoing coronary artery surgery.