Propofol for pediatric tracheal intubation with deep anesthesia during sevoflurane induction: dosing according to elapsed time for two age groups.

Abstract Study Objective To determine, for two different age groups, the effect of duration of sevoflurane administration on the amount of propofol needed when performing tracheal intubation. Design Classic Dixon's Up-and-Down sequential method. Setting University based operating rooms. Patients 106 ASA physical status 1 and 2 patients aged one to 11 years. Interventions Patients were allocated to the 1–6 year (≥ 12 and 2 O), with N 2 O discontinued and sevoflurane dialed to 5% after one minute and 1.5 minutes for the younger and older age groups, respectively. Intravenous access was obtained and propofol was promptly administered. Propofol dose was determined according to age group and whether propofol was given 2–4, 4–6, or 6–8 minutes after the start of sevoflurane induction, with Dixon's Up and Down Method used separately for each specific age/time group. Tracheal intubation conditions one minute after propofol were evaluated. Measurements Isotonic regression determined propofol ED 50 estimates for excellent tracheal intubation conditions, and linear regression determined the effect of propofol dose on change in systolic blood pressure (SBP). Main Results Estimated propofol ED 50 doses for 1–6 year olds, with 95% confidence intervals (CIs), were 1.48 mg/kg (0.80, 2.03), 0.00 mg/kg (0.00, 0.38), and 0.07 mg/kg (0.00, 0.68) in the 2–4, 4–6, and 6–8 minute groups, respectively, with estimated differences between the 2–4 minute group versus the 4–6 and 6–8 minute groups being 1.47 mg/kg (95% CI=1.04, 2.06) and 1.41 mg/kg (95% CI=0.74, 2.04), respectively. Estimated propofol ED 50 doses for 6–11 year olds, with 95% CIs, were 2.35 mg/kg (1.97, 2.45) and 2.33 mg/kg (1.59, 2.45) in the 2–4 and 4–6 minute groups, respectively. Diminutions in SBP at one minute and two minutes after propofol administration were dose dependent for children 1–6 years of age, decreasing 5.3% and 8.1% for each 1 mg/kg of propofol, respectively. Conclusion The amount of propofol needed to supplement sevoflurane in children 1–6 years of age can be expected to decrease after 4 minutes of sevoflurane.