This study was designed to compare the hemodynamic changes in response to direct laryngoscopy with using the McCoy or Macintosh blade.

Seventy seven patients were randomly allocated into two groups. The induction of anesthesia was done with target controlled infusion of propofol (5 µg/ml) and remifentanil (3 ng/ml) and vecuronium 0.1 mg/kg was also given. The vocal cords were visualized with either the McCoy or the Macintosh laryngoscope blade, and then tracheal intubation was performed. The heart rate and blood pressure were measured just before induction, at intubation and at 1, 3 and 5 minutes after intubation.

There were no significant differences in the blood pressure and heart rate responses to tracheal intubation with using the McCoy or Macintosh blade. But, in the Macintosh groups, the blood pressure at 1 and 3 minutes and the heart rate at 1 minute after intubation were increased significantly compared with the preintubation values. Also, in the McCoy groups, the blood pressure and heart rate at 1 minute after intubation were significantly higher than the preintubation values.

The McCoy and the Macintosh blade show similar changes in heart rate and blood pressure after tracheal intuba tion.