We evaluated the possibility of tracheal intubation and intubating conditions following anesthetic induction with propofol 2.5 mg/kg, with or without fentanyl, lidocaine as pretreatment and without neuromuscular blocking agents.

Thirty six patients, ASA I or II, under various surgical procedures were randomly assigned into three groups according to anesthetic pretreatment: group 1 received only propofol : group 2, propofol and fentanyl 4 mcg/kg and group 3, propofol, fentanyl 4 mcg/kg and lidocaine 1 mg/kg. Two minutes after administration of lidocaine, we administered the fentanyl over 20 seconds, and then one minutes after fentanyl, administered propofol over 40 seconds. After loss of consciousness, intubation of the trachea was performed and intubating conditions were assessed as acceptable or unacceptable on the basis of a scoring system depending on the easiness of laryngoscopy, vocal cord position and coughing when tracheal tube was inserted.

The overall assessment of intubating conditions were acceptable in 58 %, 75 % and 83 % of patients in groups 1-3, respectively. Supplementing fentanyl with lidocaine improved intubating conditions and was less coughing among three groups (p<0.01).

The use of propofol without neuromuscular blocking agent was not adequate for intubation since laryngotracheal reflexes were not suppressed. Pretreatment with or without fentanyl and lidocaine did not improve the responses sufficiently enough to perform intubation safely.