Dose requirements of remifentanil for intubation in nonparalyzed Chinese children

Background: The objective of this study was to determine ED50 and ED95 of remifentanil for intubation combined with propofol in nonparalyzed Chinese children.

Methods: Forty-seven American Society of Anesthesiologists Class I children aged 4-11 years weighing 14-33.5 kg underwent general anesthesia with 2.5 mg·kg(-1) of intravenous propofol followed by remifentanil in Wenzhou, China. The initial dose of remifentanil was 2.5 μg·kg(-1) injected over 60 s. Intubation was attempted 30 s after the completion of remifentanil injection. Level of difficulty to intubate was graded on a scoring system. If the initial intubation condition was deemed satisfactory, subsequent remifentanil doses were decreased by 0.25 μg·kg(-1). If the intubating condition was deemed unsatisfactory, subsequent remifentanil doses were increased by 0.25 μg·kg(-1). Mean arterial pressure, heart rate, and pulse oximetry were documented before and after induction, immediately after intubation, and 1 min after intubation.

Results: The ED50 of remifentanil used to render a satisfactory intubating condition used in combination with 2.5 mg·kg(-1) of propofol in nonparalyzed Chinese children was 2.30 μg·kg(-1) (95% confidence interval: 2.28-2.31 μg·kg(-1)), and the ED95 is 2.75 μg·kg(-1) (95% confidence interval: 2.59-3.35 μg·kg(-1)). These doses were lower than previously reported.

Conclusion: When used in combination with 2.5 mg·kg(-1) of intravenous propofol, ED50 and ED95 of remifentanil for adequate intubation in nonparalyzed children were lower than previously reported, at 2.30 and 2.75 μg·kg(-1), respectively.