Effect of fentanyl and nitrous oxide on the desflurane anesthetic requirement.
The minimum alveolar anesthetic concentration (MAC) of desflurane (I-653) was determined when administered with 60% nitrous oxide (N2O) in oxygen after a standardized induction sequence consisting of 0, 3, 6, or 9 micrograms/kg intravenous (IV) fentanyl followed by 3-6 mg/kg IV thiopental and 1.5 mg/kg IV succinylcholine. For comparison, we also determined the isoflurane MAC with 60% N2O in oxygen after an induction dose of 3 micrograms/kg IV fentanyl and similar doses of thiopental and succinylcholine. All patients were undergoing elective surgical procedures. The minimum alveolar anesthetic concentration in patients given isoflurane and 60% N2O with 3 micrograms/kg fentanyl was 0.4%, approximately 20% below previously reported MAC values for isoflurane with 60% N2O alone. The minimum alveolar anesthetic concentration of desflurane with 60% N2O plus 0, 3, 6, and 9 micrograms/kg IV fentanyl was 3.7%, 3.0%, 1.2%, and 0.1%, respectively. Thus, the MAC-lowering effect of 3 micrograms/kg IV fentanyl appears to be similar with both isoflurane and desflurane. Fentanyl, 3-9 micrograms/kg IV, produces dose-dependent decreases in the MAC of desflurane.
Ghouri
A F
AF
Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri 63110.
White
P F
PF
D000328:Adult; D000769:Anesthesia, Inhalation; D000777:Anesthetics; D000077335:Desflurane; D004357:Drug Synergism; D005260:Female; D005283:Fentanyl / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D007530:Isoflurane / Q000031:analogs & derivatives*; D008297:Male; D008875:Middle Aged; D009609:Nitrous Oxide / Q000008:administration & dosage / Q000494:pharmacology*; D011897:Random Allocation
D000777:Anesthetics; D000077335:Desflurane; D007530:Isoflurane; D009609:Nitrous Oxide; D005283:Fentanyl