Dose-Response of Propofol for Tracheal Intubation in Children Correlated to Intubation Condition Score and Cerebral State Index. Randomized, Double-Blinded Trial

Abstract

Background: Avoiding neuromuscular blocking drugs may prevent the potential complications of their use if they are not required for the planned procedure. This study was designed to estimate dose-response of propofol for tracheal intubation in children correlated to Intubation Condition Score and Cerebral State Index (CSI) without neuromuscular blocking drugs. Methods: 56 children (ages 3-8 years), ASA physical status I and II, weight 13-35 Kg, admitted for adenotonsillectomy were included. Children were randomly divided into four groups to receive propofol by Target Controlled Infusion (TCI) at different concentrations: 3.0 μg•ml-1, 3.5 μg•ml-1, 4.0 μg•ml-1, 4.5 μg•ml-1. At time T0 remifentanil infusion 0.5 μg•kg-1•min-1 was started. After 4 min, time T1, children received propofol according to their group. At time T2 (8 min after T0) tracheal intubation was carried out, Intubation Condition Score and CSI values at time T2 were assessed. Results: The results show that increasing propofol plasma concentrations from 3.0 μg•ml-1 to 4.5 μg•ml-1, the number of patients with acceptable intubating conditions, increased to 100%. There was a statistically significant difference with respect to Intubating Condition Score: 3.0 μg•ml-1 vs 4.5 μg•ml-1 and 3.0 μg•ml-1 vs 4.0 μg•ml-1. With reference to CSI values, a statistically significant difference was observed between 4.5 μg•ml-1 and the other 3 concentrations. We observed a significant difference in patients with CSI≤50 versus CSI>50 among the four propofol groups. Therefore, we detected a significant difference in the Intubation Condition Score between the CSI≤50 and CSI>50 groups. Conclusions: The administration of propofol at 4 and 4.5 μg•ml-1, coadministered with remifentanil 0.5 μg•kg-1•min-1, provided clinically acceptable conditions for tracheal intubation. In our opinion the use of CSI monitoring may be of practical value in producing acceptable intubating conditions in children.