不同气体吸入对高原缺氧犬血流动力学及血气的影响

目的: 观察氧气(O2)、二氧化碳(CO2)及氧气与二氧化碳混合气(O2 CO2)对急性高原病的防治情况.方法: 将15条杂种犬放入减压舱,以3 m/s的速度到达4500 m高度,持续减压3 d,造成急性高原缺氧模型,利用右心漂浮导管法对急性缺氧犬分别吸入O2,CO2及O2 CO2,动态观察血流动力学及血气的变化情况.结果: 急性缺氧犬分别吸入O2,CO2及O2 CO2后,各组自身前后比较,氧气组能减慢HR,提高SaO2,PaO2,PaCO2,降低mPAP,改善血流动力学(P<0.001～0.05),但对血液中HCO3-的改善不明显;CO2组能提高血液中HCO3-,PaCO2(P<0.001～0.05),但不能提高SaO2,PaO2,不能降低mPAP而增加心脏负担;O2 CO2组则既有益于血流动力学的好转,又有利于血气的改善(P<0.001～0.05).结论: O2 CO2混合对高原缺氧有一定的协同作用,优于CO2 及O2的单独使用,可能对急性高山病(AMS)的防治有益.

Effects of breathing different air containing 30 mL/L carbon dioxide,950 mL/L oxygen or a mixture of 30 mL/L carbon dioxide/950 mL/L oxygen on hemodynamics and blood-gas in high-altitude hypoxia dogs

AIM: To observe the preventive and therapeutic effects of carbon dioxide,oxygen or a mixture of carbon dioxide/oxygen on acute mountain sickness.METHODS: The changes of hemodynamics and blood-gas in acute hypoxia dogs were observed dynamically through Swan-Ganz catheter.RESULTS: After the acute hypoxia dogs breathed 950 mL/L O 2,their heart rate (HR) slowed,their oxygen saturation (SaO 2),arterial partial pressure of O 2 (PaO 2) and the arterial partial pressure of CO 2 (PaCO 2) increased,and the mean pulmonary arterial pressure (mPAP) decreased.Significant difference was found compared with those before breathing 950 mL/L O 2(P<0.001-0.05).After the dogs breathed 30 mL/L CO 2,their HCO 3 - and arterial partial pressure of CO 2 (PaCO 2 ) improved(P<0.001-0.05),but no marked changes were observed in the SaO 2,PaO 2 and mPAP.After the dogs breathed a mixture of carbon dioxide/oxygen,both hemodynamics and blood-gas were improved(P<0.001-0.05).CONCLUSION: Our results show that the combination of CO 2 and O 2 has a synergistic effect and the combination is better than CO 2 or O 2 alone,which can be used in the management of AMS.