Intubation with propofol: evaluation of pre-treatment with alfentanil or lignocaine

The effect of lignocaine or alfentanil pre-treatment on conditions at orotracheal intubation following induction with propofol, but without the use of muscle relaxants, were compared in a prospective, controlled, double-blind study. Forty five healthy patients undergoing elective surgery were randomly allocated to receive either 0.9% saline (control), alfentanil 20 micrograms/kg-1, or lignocaine 1.5 mg kg-1 prior to induction with propofol 2.5 mg kg-1. Ease of intubation was scored on a four point scale from 'excellent' = 1 to 'not possible' = 4. Alfentanil pre-treatment allowed intubation in 93% of patients compared to 60% in each of the groups pre-treated with lignocaine or saline. Intubation scores of 1 or 2 were obtained in 14 out of 15 patients (93%) in the alfentanil group and this was significantly better than the lignocaine group (33%) or control group (20%). No difference was detected between the scores of the latter two groups.