狗静脉注射高渗溶液后的血流动力学分析

在15只戊巴比妥钠麻醉的开胸狗身上观察高渗溶液对血流动力学的影响,主要结果如下:1.静脉内注射50%葡萄糖溶液(3m1/kg,15s 内注毕),规律地引起心动徐缓、动脉血压降低、左心室(-dp/dt)减小、左心室 dp/dt 和心输出量增加,以及肾和股薄肌的血流阻力降低。25%甘露醇溶液具有类似作用。2.切断两侧颈迷走神经后,注射高渗溶液不再能诱发动脉低血压以及肾和股薄肌血流阻力的反射性降低,提示此类效应的传入通路主要为迷走神经。3.在切断迷走神经后注射高渗溶液,还使左心室 dp/dt 进一步增加,表明高渗溶液增强心肌收缩性。根据以上结果似可认为,静脉注射高渗溶液所致动脉血压降低,实质上反映着心输出量的增加不足以抵销外周阻力的减小。

HEMODYNAMIC EFFECTS FOLLOWING INTRAVENOUSLY INJECTING HYPEROSMOTIC SOLUTION IN DOGS

The effects of hyperosmotic solution on hemodynamics were observed in 15pentobarbital-anesthetized open-chest dogs.The main results obtained wereas follows:(1)Intravenous injection of 50% glucose solution could induce brady-cardia,systemic hypotension,decrease in left ventricular(-dp/dt),increase in leftventricular dp/dt and cardiac output,as well as reduction in renal and gracilisperfusion pressures(RPP and GPP).The responses to 25% mannitol solution wereidentical with that of hyperosmotic glucose solution.(2)Following bilateral vago-tomy,the hyperosmotic solution failed to induce hypotension and reflex decreasein RPP and GPP,thus indicating that the afferent route of the effects was mediatedmainly via the vagi.(3)After bilateral vagotomy,the increase in left ventri-cular dp/dt elicited by hyperosmotic solution was augmented.It is likely thatthe myocardial contractility was enhanced by hyperosmotic solution.On the basisof above-mentioned results,it was considered that the systemic hypotension inducedby intravenous hyperosmotic solution administration reflected essentially an in-tegrated effect of an augmented cardiac output and a decreased peripheral resistance.