氧疗对高海拔地区失血性休克救治作用的实验研究

Study on the Effect of Oxygen Therapy in the Treatment of High Altitude Hemorrhagic Shock

目的 选择理想的氧疗浓度,探讨其对高海拔地区失血性休克的治疗作用。方法 将21只家兔随机分为Ⅰ、Ⅱ、Ⅲ三组,每组7只,模拟高原环境,建立失血性休克模型,维持1 h后,行补液治疗。同时Ⅰ、Ⅱ、Ⅲ组分别给予80%、50%、30%氧气治疗,以选择理想的氧疗浓度。另15只家兔随机分为实验组(7只)和对照组(8只),同样建立失血性休克模型,维持1 h后,两组均行抗休克治疗。同时实验组给予80%氧气吸入,对照组不予氧气,动态测定两组心肌收缩性能、动脉血气。结果Ⅰ组平均动脉压(MAP)、中心静脉压(CVP)高于Ⅱ组和Ⅲ组,且动物存活时间较长,与Ⅱ组比较,差异有显著性意义(均P<0.05)。实验组动脉血氧分压(PaO2)、动脉血氧饱和度(SaO2)、碳酸氢盐(HCO3-)、动脉血二氧化碳分压(PaCO2)与对照组比较,差异有显著性意义(P<0.05,P<0.01);同时实验组的左室收缩压(LVSP)和左室压力上升及下降的最大变化速率(±dp/dtmax)显著高于对照组(均P<0.05)。结论 高海拔地区失血性休克救治中,采用80%浓度的氧疗效果优于50%、30%浓度的氧疗;氧疗对高海拔地区失血性休克具有明显的治疗作用。

Objective To determine right concentrations of oxygen used in oxygen therapy and investigate the thera-peutic effects of oxygen on high altitude hemorrhagic shock. Methods Twenty-one rabbits were exposed to a simula-ted high altitude in a hypobaric chamber and randomized into three groups, with 7 rabbits in each group. Then hemorrhagic shock was induced through bleeding to 40 mmHg of MAP. After 1 hour, the rabbits were re-perfused with balanced saline. At the same time, different concentrations of oxygen were administered to the three groups (group Ⅰ:80% FiO2, group Ⅱ : 50 % FiO2 , group Ⅲ:30 % FiO2 ) , to find the best concentrations of oxygen. After-wards, another 15 rabbits were randomly divided into two groups: experimental group (7 rabbits) and control group (8 rabbits), and hemorrhagic shock was also induced through bleeding. After 1 hour, the two groups were reper-fused with blood and balanced saline. The experimental group was given oxygen therapy with 80 % FiO2 , and no oxygen was given to the control group. Then their myocardial contraction and blood gas were monitored. Results The MAP and CVP of group Ⅰ was higher than those of the other two groups, and its mean survival time was lon-ger. Compared with the control group, the PaO2 , SaO2 , HCO3-, PaCO2 of the experimental group increased sig-nificantly (P<0. 05 or P<0. 01). The LVSP, ±dp/dtmax of the experimental group were elevated significantly in comparison with the control group (all P<0. 05). Conclusion In the treatment for high altitude hemorrhagic shock, 80% FiO2 was superior to 50% FiO2 and 30% FiO2. Oxygen therapy is effective in the treatment of high altitude hemorrhagic shock.