Abstract: To observe the hemodynamic changes during controlled hypotension (CH) induced by sodium nitroprusside (SNP) in neurosurgical patients, fifteen ASA Ⅰ～Ⅱ patients (5 male, 10 female), aged 19～55 years, undergoing elective neurosurgery were enrolled in this study. Anesthesia was maintained with 1.0 MAC isoflurane. Controlled hypotension was performed after opening dura and the MAP was reduced and maintained to 7.3～8.0 kPa (55～60 mmHg) with continuous infusion of SNP at 1.5～2 μg/(kg·min) by micro pump (Grasby, England). MAP, HR, ECG, SpO₂ were monitored. HEMOSONIC^TM 100 Monitor was used to measure PV, Acc, LVET, SV, CO and TSVR. PetCO₂, MAC was continuously measured by gas monitor (Datex, Ultima, Fenland). Hymodynamic parameters were recorded before hypotension, 5 min, 15 min and 30 min during hypotension, and 5 min and 10 min after discontinuing hypotension. During controlled hypotension, ACC、PV、CO、SV and HR increased by 20.8%～41.1%, 18.1%～26.3%, 21.6%～27.9%, 2.7%～7.6% and 20.5%～ 25.0%, respectively, compared with those before hypotension. TSVR decreased by 35.1～39.1%. Controlled hypotension with SNP for neurosurgical patients possess several advantages such as fast onset of action, decreased peripheral resistance, increased cardiac function and easy recovery of blood pressure.

Key words: sodium nitroprusside, controlled hypotention, hemodynamics