Tracheal intubation after induction of anesthesia in children with propofol - remifentanil or propofol-rocuronium

Purpose: To compare the intubating conditions after remifentanil-propofol with those after propofol-rocuronium combination with the aim of determining the optimal dose of remifentanil. Methods: in a randomized, double-blind study 80 healthy children aged three to nine years were assigned to one of four groups (n=20): 2 or 4 mu g.kg(-1) remifentanil (Re2 or Re4); 2 mu g.kg(-1) remifentanil and 0.2 mg.kg(-1) rocuronium (Re2-Ro0.2); 0.4 mg.kg(-1) rocuronium (Ro0.4). After atropine, remifentanil was injected over 30 sec followed by 3.5 mg.kg(-1) propofol and rocuronium. After 60 sec, laryngoscopy and intubation were attempted. Intubating conditions were assessed as excellent, good or poor based on ease of ventilation, jaw relaxation, position of the vocal cords, and coughing to intubation. Results: in all children intubation was successful, Overall intubating conditions were better(P < 0.01), and the frequency of excellent conditions, 85%, was higher (P < 0.01) in the Re4 group than in the Ro0.4 group. No child manifested signs of muscular rigidity. In the remifentanil groups, arterial pressure decreased 11-13% and heart rate 6-9% after anesthetic induction, and remained at that level throughout the study. Conclusion: The best intubating conditions were produced by the combination of 4 mu g.kg(-1) remifentanil and 3.5 mg.kg(-1) propofol. It provided excellent or good intubating conditions in all children without causing undue cardiovascular depression.