酚妥拉明对失血性休克家兔微循环血流动力学的影响

本研究旨在探讨酚妥拉明对失血性休克微循环血液灌流的作用.两组家兔——生理盐水对照组(n=7)和酚妥拉明治疗组(n=8),麻醉后放血至血压为5.33～6.00kPa以造成重度失血性休克.维持60min后将5mg酚妥拉明加入25ml生理盐水中静脉滴注(对照组仅滴注等量生理盐水),同时将放出的全部血液回输.观察休克及用药前后平均动脉血压、心率和肠系膜微循环变化.用显微电视录像静像步进技术测定毛细血管口径、血流速度及血流量.酚妥拉明滴往后,心率略加快,血压明显下降,血流速度和血流量显著降低,毛细血管口径两组间无明显差异.表明休克时酚妥拉明单独应用可使血压严重下降,从而加重肠系膜毛细血管的血流障碍.

Effects of Phentolamine on Microcirculatory Hemodynamics in Hemorrhagic Shock in Rabbits

The purpose of this sdudy is to prove the effects of phentolamine on microcirculatory perfu-sion in hemorrhagic shock. Two groups of rabbits,control group(n=7) and phentolamine treated one (n = 8), were put into simulated serious hemorrhagic shock. The mean arterial pressure (MAP) was maintained at 5. 33-6. 00kPa for 60min by using reservoir. Then the animal was infused with either 5 mg of phentolamine in 25ml equivalent saline and was also transfused with the shed blood via the femoral vein in the period. The MAP,heart rate (HR) and mesenteric microcirculation before and after infusion were monitored. The blood flow velocity,blood flow rate and capillary calibre were measured by means of the micro-video system frame by frame analyzing method. Following the infusion of phentolamine,HR increased mildly and MAP declined considerably. Blood flow velocity and flow rate also decreased. There was no evidence that the capillary diameter was significantly altered by treatment. The results demonstrated that the phentolamine alone can seriously reduce blood pressure and thus aggravate obstruction of blood flow in mesenteric capillary.