Effect of nicardipine and diltiazem on internal carotid artery blood flow velocity and local cerebral blood flow during cerebral aneurysm surgery for subarachnoid hemorrhage

Abstract

Study Objective: To determine the hemodynamic effects of a bolus injection of nicardipine 1 mg or diltiazem 5 mg on local cerebral blood flow (LCBF) and internal carotid blood flow velocity (ICBFV) with isoflurane anesthesia. Design: Randomized study. Setting: Inpatient neurosurgery and anesthesia clinic at a city hospital. Patients: 26 patients with subarachnoid hemorrhage who were scheduled for cerebral aneursym clipping. Interventions: A bolus injection of either nicardipine or diltiazem was administered to patients whose systolic blood pressure increased to over 150 mmHg after opening of the dura. Measurements and Main Results: After the bolus injection, both drugs rapidly decreased arterial blood pressure. Nicardipine increased LCBF [before injection, 42.1 ± 12.3 ml/100 g/min; after injection, 47 ± 10.7 ml/100g/min; ( p < 0.05 vs. control); after recovery, 42.4 ± 11.1 cm/sec], but diltiazem did not change LCBF. Nicardipine 1 mg moderately increased ICBFV [before injection, 34.2 ± 9.3 cm/sec; after injection, 40.6 ± 8.7 cm/sec ( p < 0.01 vs. control); after recovery, 34.1 ± 8.9 cm/sec], but diltiazem did not change ICBFV. In addition, venous partial oxygen pressure and saturation of the internal jugular did not change throughout the study. There was a close correlation between presurgical neurologic status and LCBF (rs = −0.743; p < 0.01) and ICBFV (rs = − 0.721; p < 0.01). Conclusions: Nicardipine increased LCBF and ICBFV, but diltiazem did not change either. These results suggest that both drugs are useful and safe for the treatment of intraoperative hypertension during cerebral aneurysm surgery.