中文摘要：

目的探究不同急性低氧对大鼠血流动力学指标的影响，旨在建立一种在海拔2260m地区、急性低氧情况下能有效、稳定研究血流动力学变化的大鼠模型。方法SD大鼠30只，随机分为20％02对照组（20％O2，80％N2）、17％O2低氧组（17％O2，83％N2）和15％02低氧组（15％O2，85％N2）。通过实时、动态监测中心静脉压（central venous pressure，CVP）、系统动脉压（system arterial pressure，Psa）、肺动脉压（pulmonary artery pressure，PAP）、左心房压（left atrial pressure，LAP）、升主动脉血流量（ascending aorta blood flow，ABF）、气道阻力（airway pressure，Paw）和心率（heart rate，HR）等血流动力学指标，观察低氧条件（17％O2、15％O2）下各项指标的变化，计算总外周循环阻力（Toll pressure resistance，TPR）和肺循环阻力（pulmonary vascular resistance，PVR）来反映不同急性低氧对血流动力学的影响。结果与对照组相比，15％O2低氧组的Psa降低（P〈0．05），而17％O2低氧组无明显变化；给予17％O2和15％O2的低氧刺激后ABF均降低（P〈0．05），15％O2低氧组比17％O2低氧组下降更为显著；17％O2低氧组的PAP在低氧刺激过程中仅出现了一过性的升高，而15％O2低氧组PAP在1min内就出现了明显升高（P〈0．05）；与对照组相比两低氧组CVP、HR、LAP和Paw没有明显改变；通过计算得出15％O2低氧组PVR明显升高（P〈0．05），而TPR无明显变化。结论在海拔2260m的西宁地区应用17％O2的低氧刺激可以引起肺循环血流动力学的一过性改变，但无法持续监测；15％O2的低氧刺激是观测急性低氧影响麻醉大鼠血流动力学的适宜条件。

英文摘要：

Objective Explore the effect of different acute hypoxia on rats＇ hemodynamic,in order to establish an effective and stable animal model that can be used for researching hemodynarnics changes in acute hypoxia. Methods 30 healthy SD rats were randomly divided into control group（20% O2,80% N2 ）, 17% O2 hypoxic group （17% O2,83% N2）and 15% O2 hypoxic group（ 15% O2 ,85% N2）.Then the changes of hemodynamics in 17% and 15% hypoxia, the system arterial pressure （Psa）, central venous pressure （CVP）, pulmonary artery pressure （PAP）, left atrial pressure （ LAP）, ascending aorta blood flow （ ABF）, heart rate （HR） and airway pressure （Paw） were ob- served.The anesthetized rats were monitored continuously with real-time and the effect of hemodynamics were ex- plained by the total peripheral resistance （TPR）and pulmonary vascular resistance （PVR）in different acute hypoxia. Results The Psa of 15% O2 hypoxic group was significantly lower（ P〈0.05 ）than that of the control group ,but the 17% O2 hypoxic group had not been changed.The ABF,both of 17% O2 hypoxic group and 15% O2 hypoxic group, were lower than that of control group（P〈0.05） ,but 15% O2 hypoxic group was significantly lower than 17% O2 hy- poxic group.PAP of 17% O2 hypoxic group was increased transiently in acute hypoxia, while PAP of 15% O2 hy- poxie group was increased significantly （ P〈O.05 ） in lmin.The CVP, HR, LAP and Paw of two hypoxic groups did not change.The PVR was obviously increased in 15% O2 hypoxic group（P〈O.05）, and the TPR did not change. Conclusion At the 2 260 m altitude ,the hemodynamics can be transiently changed in 17% O2 acute hypoxia,but it is unable to be detected continuously. 15% O2 hypoxia is an effective status to observe the changes of hemodynamic in anesthetie rats.