Comparison of different doses of remifentanil on the cardiovascular response to laryngoscopy and tracheal intubation

Wa have compared three bolus and infusion regimens of remifentanil on the c ardiovascular response to laryngoscopy and orotracheal intubation in three groups of 20 ASA I-II female patients, in a randomized, double-blind study. Patients in group I received glycopyrrolate 200 mu g i.v. followed by a bo lus dose of remifentanil 1 mu g kg(-1) over 30 s and an infusion of remifen tanil at a rate of 0.5 mu g kg(-1) min(-1). The other patients received rem ifentanil 0.5 mu g kg(-1) over 30 s and an infusion of 0.25 mu g kg(-1) min (-1) with (group 2) or without (group 3) pretreatment with glycopyrrolate 2 00 mu g. All patients then received a sleep dose of propofol, rocuronium 0. 6 mg kg(-1) and 1% isoflurane with 67% nitrous oxide in oxygen. Laryngoscop y and tracheal intubation were performed 3 min later. Heart rate and arteri al pressure were recorded at 1-min intervals from before induction of anaes thesia until 5 min after intubation. Baseline heart rate was similar in all groups, but decreased in group 3 (no glycopyrrolate) after induction and r emained significantly lower after intubation compared with the other groups (P<0.05). Heart rate and arterial pressure increased slightly after intuba tion in each group but there were no significant differences in mean arteri al pressure between groups at any time. The incidence of bradycardia (one p atient in group 2) and hypotension (two patients in groups 1 and 2 and thre e patients in group 3) was low.