This study was conducted to compare the effects of remifentanil, lidocaine, nicardipine and nitroglycerin used in conjunction with thiopental-sevoflurane on hemodynamic changes induced by direct laryngoscopy and tracheal intubation.

Seventy-five ASA class I or II patients scheduled for elective surgery were randomly divided into 5 groups. After induction of anesthesia with thiopental, sevoflurane and rocuronium, they were administered an intravenous bolus of either saline (Group S), remifentanil 1 µg/kg (Group R), lidocaine 1.5 mg/kg (Group L), nicardipine 20 µg/kg (Group N) or nitroglycerin 2 µg/kg (Group G). Tracheal intubation was then conducted 90 seconds after the drug was administered. The systolic blood pressure, diastolic blood pressure and heart rate were measured prior to the administration of anesthesia, before intubation, at 1 min after intubation and at 3 min after intubation for each patient.

The systolic blood pressure, diastolic blood pressure and heart rate at 1 min after intubation were significantly lower in Group R than in Group S. In addition, the systolic blood pressure and diastolic blood pressure prior to intubation were significantly lower in Group N than in Group S.

Remifentanil 1 µg/kg was most effective at controlling hemodynamic changes induced by direct laryngoscopy and tracheal intubation when compared with lidocaine, nicardipine and nitroglycerin.