Abstract: The aim was to observe the effects of controlled hypotension on regional cerebral blood flow (rCBF) in intracranial aneurysm surgery. Twenty patients were randomly divided into isoflurane (A, n=10) and nimodipine (B, n=10) groups. During controlled hypotension, mean artery pressure(MAP) was maintained at 8.0～8.7(60～65 mmHg) kPa in both groups. In group A, Isoflurane inhalation concentration was increased to 1.4～1.6 MAC. In group B, a bolus of nimodipine was given, followed by a continuous infusion of 10～100 μg/(kg·h). After aneurysm was clipped, papaverine was applied to all major vessels for 10 min. RCBF was continuously measured by laser Doppler flowmeter during the procedure. After clipping aneurysm rCBF decreased significantly in group A compared with before clipping aneurysm(P<0.05). There was no significant change in group B(P>05). After local application of papaverine, rCBF significantly increased in both groups(P<0.05), but the degree of increasing in group A was higher than that in group B(P<0.05). When intraoperative hypotension is induced by nimodipine rCBF is steadier than it is induced by isoflurane.

Key words: controlled hypotension, brain regional blood flow, intracranial aneurysm