Use of EEG spectral edge as index of equipotency in a comparison of propofol and isoflurane for maintenance of general anaesthesia.
Propofol and isoflurane were compared for haemodynamic stability and recovery time as main anaesthetic agents for maintenance in a total of 43 ASA I and II patients in uncomplicated operations lasting at least 30 min. The premedication (oral diazepam), induction (thiopentone-fentanyl-suxamethonium) and maintenance protocol (N2O-O2 2:1 litre min-1, fentanyl and vecuronium in incremental doses) were identical for all patients. In one group of 20 patients, propofol was used in continuous intravenous (i.v.) infusion (starting dose 3 mg kg-1 h-1), while in the second group of 23 patients, isoflurane was administered in a starting concentration of 1%. To improve the equipotency of the two agents in all cases the dose of the main anaesthetic was titrated to keep the EEG 90% spectral edge frequency (SEF-recorded by processed EEG monitor) between 8 and 12 Hz. Mean blood pressure (BP) and heart rate (HR) deviations of +/- 20% from the baseline were recorded. The incidence of mean blood pressure deviations/case in the propofol group was less than half of those occurring in the isoflurane group (0.45 vs. 0.96 P = 0.04). The mean duration of blood pressure deviation from baseline value was 5.5 min in the propofol group vs. 16.8 min in the isoflurane group (P = 0.01). The recovery intervals were significantly shorter in the propofol group (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
Division of Anesthesiology, Ben-Gurion University of the Negev, Faculty of Health Sciences, Soroka Medical Center, Beer-Sheva, Israel.
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GM
Gurman
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Fajer
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Porat
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Schily
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Pearlman
D000293:Adolescent; D000328:Adult; D000368:Aged; D000762:Anesthesia Recovery Period; D000768:Anesthesia, General; D000769:Anesthesia, Inhalation; D000771:Anesthesia, Intravenous; D001364:Awareness / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D003071:Cognition / Q000187:drug effects; D004569:Electroencephalography / Q000187:drug effects* / Q000379:methods; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007530:Isoflurane / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D008297:Male; D008568:Memory / Q000187:drug effects; D008875:Middle Aged; D015742:Propofol / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D012815:Signal Processing, Computer-Assisted; D013810:Therapeutic Equivalency
D007530:Isoflurane; D015742:Propofol