Tracheal intubation after induction of anaesthesia with propofol, alfentanil and lidocaine without neuromuscular blocking drugs in children

In a double-blind study, intubating conditions and haemodynamic responses were assessed in two age-groups of 45 ASA I-II children, with mean ages of 2.4 and 6.3 years, premedicated with oral midazolam and atropine. The children were randomly allocated to one of three groups: aifentanil 20 μg · kg-1 + lidocaine 1 mg · kg-1 (AIRO + Lign); alfentanil 20 μg μ kg-1 (Alf20); or alfentanil 40 μg · kg-1 (Alf40), followed by propofol 3.5 mg · kg-1 in the children aged 1–3 years and 3.0 mg · kg-1 in the older children. Intubating conditions, 40 s after the administration of propofol, were assessed as good, moderate or impossible on the basis of jaw relaxation, ease of insertion of the endotracheal tube and coughing during intubation. In the younger age group the frequencies of good, moderate or impossible intubating conditions were 87, 13 and 0% in the Alf40, 40, 60 and 0% in the Alf20 (P < 0.05 compared to the Alf40 group) and 53, 47 and 0% in the Alf20 + Lign group. In the older age group the corresponding frequencies were 60, 33 and 7% in the Alf20 + Lign, 47, 53 and 0% in the Alf20 and 47, 40 and 13% in the Alf40 group. All the drugs prevented any increase in arterial pressure and heart rate after tracheal intubation. The QTc interval of the EGG was always in the normal range. Clinically important bradycardia did not occur. In conclusion, the best intubating conditions occurred after propofol 3.5 mg · kg-1 and alfentanil 40 μg · kg-1 in the younger age group. In the other children good or moderate intubating conditions occurred in 87–100% after all the drugs used in the present study.