Comparison of intravenous metoprolol, verapamil and diltiazem on the attenuation of haemodynamic changes associated with tracheal extubation

Changes in heart rate, systolic, diastolic and mean blood pressure were measured after extubation in 60 ASA Grade I and II patients to assess the effects of diltiazem (0.2 mg kg^-1), verapamil (0.05 mg kg^-1) and metoprolol (0.02 mg kg^-1) given as a bolus 2 min before tracheal extubation. All the haemodynamic variables measured increased significantly after extubation in the control and diltiazem groups when compared with the base-line recordings (P < 0.05). Metoprolol effectively blocked the increases in heart rate after extubation and the increase in blood pressure in this group was less when compared with the control group (P < 0.05). Verapamil alleviated the increase in both heart rate and blood pressure. However, profound hypotension and bradycardia requiring therapy, occurred in the verapamil group. For this reason, careful observation is necessary when using verapamil and the routine use of this drug in patients with coronary artery disease requires further studies.