Effect of Nifedipine on Cardiovascular Response to Tracheal Intubation

Laryngoscopy and tracheal intubation after induction of anesthesia with thiopental are frequently associated with hypertension and tachycardia. The transient circulatory response are innocuous in healthy patients but detrimental to those with ischemic heart disease or increased ICP.

The effect of sublingual and intranasal nifedipine was studied in 51 patients undergoing elective surgery. Patients were allocated randomly to receive sublingual or in intranasal nifedipine 10mg 5 minutes before induction. Anesthesia was induced thiopintal 5mg/kg and tracheal intubation was facliitated with succinylcholine 2mg/kg. The systolic, diastolic blood pressure, heart rate and rate-pulse product were recorded before the induction, 0, 2, 8, 13 minutes after intubation and skin incision.

The results were as follows :

1) Significant attenuation of increase systolic BP in intranasal group compared to control group immediately after intubation.

2) Significant attenuation of increase in diastolic BP in intranasal group compared to control group.

3) Heart rate was significantly increased intranasal group and sublingual group compared to control group.

4) Slight obtundation of increase in rate-pulse product in sublingual and intranasal group, but not significant.

In conclusion, intranasal nifedipine was effective method to attenuate the hypertensive response to laryngoscopy and tracheal intubation.