Fentanyl dose for the Insertion of Classic™ Laryngeal Mask Airways in Non-Paralysed Patients Induced with Propofol 2.5 mg/kg

Abstract

The aim of this randomised, controlled trial was to determine the optimum dose of fentanyl in combination with propofol 2.5 mg.kg-1 when inserting the Classic™ Laryngeal Mask Airway. Seventy-five ASA I or II patients were randomly assigned to five groups of fentanyl dosage: 0 µg.kg-1 (placebo), 0.5 µg.kg-1 , 1.0 µg.kg-1 , 1.5 µg.kg-1 and 2.0 µg.kg-1. Anaesthesia was induced by first injecting the study drug over 10 seconds. Three minutes after the study drug was injected, propofol (2.5 mg.kg-1) was injected over 10 seconds. The Classic™ Laryngeal Mask Airway was inserted four minutes and 30 seconds after injection of the study drug. Insertion conditions were evaluated using a four-category score. Thirty-nine males and 36 females aged 19 to 59 years were studied. The incidence of prolonged apnoea increased as fentanyl dose increased. We found that there was a high rate of successful first attempt at insertion with 1 µg.kg-1 and 1.5 µg.kg-1 , 93% and 87% respectively, compared to 87% in the 2.0 µg.kg-1 group. The 1.0 µg.kg-1 group also achieved an 80% optimal insertion conditions score of 4, compared to 73% in the 1.5 µg.kg-1 group and 80% in the 2 µg.kg-1 group. Therefore we recommend 1.0 µg.kg-1 as the optimal dose of fentanyl when used in addition to propofol 2.5 mg/kg for the insertion of the Classic™ Laryngeal Mask Airway.

Dexmedetomidine with propofol versus fentanyl with propofol for insertion of Proseal laryngeal mask airway: A randomized, double-blinded clinical trial

“…[67] Tan and Wang have shown that fentanyl increases the incidence of prolonged apnea in a dose-dependent manner. [16] Dexmedetomidine itself lacks respiratory depressant effect, and has shown to cause significant increase in RR during its infusion due to its action at multiple sites including locus ceruleus, pulmonary vasculature, and carotid body by stimulating respiratory center. [17] Apnea occurring in few patients in PD group may be due to the effect of 2.5 mg/kg of propofol.…”

Comparative evaluation of i-gel® insertion conditions using dexmedetomidine-propofol versus fentanyl-propofol - A randomised double-blind study

“…The predetermined dose of propofol induction (2 mg/kg) along with the timing of administering propofol injection and i-gel ® insertion after pre-treatment with fentanyl or dexmedetomidine, were as suggested by previous researchers. [619202122] The aim was to achieve effective synergistic levels of the drug combinations used before I gel insertion.…”