不同渗透压不同氧浓度液体对高原失血性休克大鼠复苏效果的对比观察

目的 观察不同渗透压、不同氧浓度液体对高原创伤失血性休克大鼠的复苏效果.方法 在海拔3 658 m地区按压力-容量监测(Weigger)法复制失血性休克SD大鼠模型,失血1 h后分别给予生理盐水、75 g/L的高渗盐水、60 g/L右旋糖酐40注射液、75 g/L高渗盐水加60 g/L右旋糖酐40溶液、高渗氯化钠羟乙基淀粉40(霍姆)注射液4 ml/kg进行复苏(制成高氧溶液,以4 ml/kg经颈外静脉注入),观察不同液体对高原失血性休克大鼠的血压、血气、心室内压、肺和脑组织含水量、存活时间和2 h存活率的影响.结果 给予休克动物不同液体治疗后,均能升高血压、提高动脉血氧分压(PaO2).增加左室收缩压,提高左室内压上升和下降最大速率(±dp/dt max),延长存活时间和提高存活率(P＜0.05或P＜0.01).但以高渗液体和高渗高胶液体复苏后存活时间明显延长,尤其以加氧后的高渗高胶液复苏存活时间和存活率成倍增加,并且血压稳步上升,PaO2明显增高,左室收缩压明显提高,动脉血二氧化碳分压(PaCO2)无明显变化,4 ml/kg液体量不增加肺、脑组织含水量.高氧液体复苏对右心室压力没有影响,在加氧液体复苏的开始右心室压力有明显降低,说明静脉输氧能降低肺动脉压,改善右室功能.结论 不同渗透压、不同氧浓度液体对高原失血性休克大鼠均有治疗作用.但以加氧后的高渗高胶液效果更好.

Effects of liquids with different osmotic pressure and different oxygen concentration on resuscitation of hemorrhagic shock at high altitude in rat

OBJECTIVE: To compare the effects of liquids with different osmotic pressure and different oxygen concentration on resuscitation of hemorrhagic shock at high altitude. METHODS: Hemorrhagic shock model of Sprague-Dawley (SD) rats was reproduced by Weigger method at the altitude of 3 658 meters. After 1 hour blood loss, the rats were treated either with normal saline, 75 g/L hypertonic saline solution, 60 g/L dextran 40 solution, solution of 75 g/L hyperotonic saline solution with 60 g/L dextran 40, or hypertonic sodium chloride hydroxyethyl starch 40 solution, and all the above solutions were oxygenated with oxygen by high pressure. All the solutions were infused via external jugular vein (4 ml/kg) to resuscitate the rats, and the effects of different solutions on blood pressure (BP), blood gas, intraventricular pressure, water contents of lung or brain, survival time and survival rates were observed. RESULTS: The BP, mean arterial pressure (MAP), partial pressure of oxygen in artery (PaO(2)), left ventricular systolic pressures (LVSP), maximum upstroke velocity (+dp/dt max) and maximum descending velocity (-dp/dt max) of intraventricular pressure, survival time and survival rate were increased (P<0.05 or P<0.01), but the survival time of the rats in groups treated with hypertonic solutions or hypertonic colloid solutions was obviously prolonged. In particular, survival time and survival rate of the rats in the groups treated with hypertonic colloid solutions were raised more significantly than those of other groups. Besides, the results showed that BP rose steadily in all the groups, PaO(2) and LVSP of these groups significantly increased, but partial pressure of carbon dioxide in artery (PaCO(2)) showed no significant change. Infusion of 4 ml/kg of liquids did not increase water contents of lung or brain. Hyperoxic solutions had no effect on the right ventricular pressure, but the oxygenated liquids could lower the right ventricular pressure at the beginning of resuscitation, suggesting that oxygen transfer through the vein could lower the pulmonary artery pressure and improve the right ventricle function. CONCLUSION: Liquids with different osmotic pressure and at different oxygen concentration showed therapeutical effect on hemorrhagic shock at high altitude in rat, with hypertonic colloid solution being the best among the liquids under examination.