Dose of propofol for laryngeal mask airway insertion in children: Effect of premedication with midazolam

Abstract

We determined the dose-response curves and effective doses of propofol for insertion of the laryngeal mask airway (LMA) in 50 unpremedicated children and in 60 children premedicated with midazolam, aged 3-12 yr. One of several doses of propofol was administered i.v, over 15 s to groups of 10 children, and conditions for LMA insertion were assessed at 60 s. The dose-response curves were parallel (P = 0.94), but the curve for premedicated children was shifted significantly to the left of that for unpremedicated children and propofol requirements were reduced by one-third (P < 0.0001). The doses required for satisfactory LMA insertion in 50% and 90% of unpremedicated patients (ED50 ED90) (95% confidence interval) were 3.8 (3.4-4.2)mgkg-1 kg-1, respectively; those for were 2.6 (2.2-2.8)mgkg-1 and 3.6(3.2-4.3)mgkg-1, respectively.