Effect of nicardipine on the blood flow velocity in the vessel near a cerebral aneurysm of the internal carotid artery during cerebral aneurysm surgery: its therapeutic use for intra-operative hypertension.

: Seven patients scheduled for clipping of an aneurysm of the internal carotid artery after subarachnoid haemorrhage, were studied in order to evaluate the efficacy of a bolus injection of nicardipine (2 mg) in the treatment of intra-operative hypertension on the blood flow velocity of vessel near the aneurysm under isoflurane anaesthesia. The blood flow velocity of the vessel near the aneurysm was measured using a 20 MHz ultrasound Doppler flowmeter. Nicardipine bolus significantly decreased the mean arterial blood pressure by about 30% (P < 0.01). The blood flow velocity of the internal carotid artery increased after the nicardipine bolus (from 43.3 +/- 9.9 to 51.7 +/- 15.0 cm s-1) (P < 0.05) but returned to the pre-injection level within 30 min (43.9 +/- 10.4 cm s-1). Nicardipine proved effective for control of intra-operative hypertension during aneurysm clipping.