Fentanyl dose-response curves when inserting the LMA Classic laryngeal mask airway.
Probit analysis was used to predict an optimal dose of fentanyl, co-administered with propofol 2.5 mg.kg(-1), when inserting the laryngeal mask airway. In all, 21 male and 54 female healthy Chinese patients, aged 18-63 years, requiring anaesthesia for minor surgery were recruited. They were assigned to one of five groups: placebo, 0.5, 1.0, 1.5 and 2.0 microg.kg(-1). Insertion was performed 90 s after administration and insertion conditions assessed using a six-category score. Dose-response curves could only be drawn for swallowing and movement categories, and only the ED(50) could be predicted with certainty. To provide optimal conditions in over 95% of patients, fentanyl doses well above the clinical range were required. A standard fentanyl dose of 1 mug.kg(-1), co-administered with propofol 2.5 mg.kg(-1), provided optimal conditions in 65% of cases. Ninety seconds may have been insufficient time for fentanyl to reach its peak effect.
Wong
C M
CM
Department of Anaesthesia & Intensive Care, Prince of Wales Hospital, Shatin, New Territories, Hong Kong.
Critchley
L A
LA
Lee
A
A
Khaw
K S
KS
Ngan Kee
W D
WD
D000293:Adolescent; D000328:Adult; D000701:Analgesics, Opioid / Q000008:administration & dosage*; D018686:Anesthetics, Intravenous; D001794:Blood Pressure / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005260:Female; D005283:Fentanyl / Q000008:administration & dosage*; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007442:Intubation, Intratracheal / Q000379:methods; D017214:Laryngeal Masks; D008297:Male; D008875:Middle Aged; D013511:Minor Surgical Procedures; D015742:Propofol; D016037:Single-Blind Method
D000701:Analgesics, Opioid; D018686:Anesthetics, Intravenous; D005283:Fentanyl; D015742:Propofol