Dosing study of remifentanil and propofol for tracheal intubation without the use of muscle relaxants

Sixty ASA I and II patients, premedicated with midazolam, were administered propofol 2 mg x kg-1 and remifentanil 3 microg x kg-1 (group R3), remifentanil 4 microg x kg-1 (group R4) and remifentanil 5 microg x kg-1 (group R5). Laryngoscopy and intubation were performed 1 min after the administration of the study drugs and the intubating conditions were assessed. Good to excellent conditions were observed in 12 patients in group R3 compared with 19 patients each in groups R4 and R5 (p = 0.004). Significant reductions in mean arterial pressure (MAP) and heart rate (HR) after administration of the study drug were observed in each group, p < 0.01. There was, however, no difference in mean MAP and HR between the three groups at all time points. We conclude that remifentanil 4-5 microg x kg-1 may reliably provide good to excellent conditions for tracheal intubation when administered after propofol 2 mg x kg-1.