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 bloodª²gas in highª²altitude hypoxia dogs

    XIE Yongª²Hong1£¬2,QIAN Guiª²Sheng1,JIN Faª²Guang2,YIN Zhenª²Jie2,ZHANG Qing1,LIU Fuª²Yu3

    1PLA Institute of Respiratory Diseases,3Department of Pathophysiology£¬Third Military Medical University,Chongqing 400037,China,2Department of Respiratory Diseases,Tangdu Hospital,Fourth Military Medical University,Xi¬ðan 710038,China

    ¡¾Abstract¡¿ 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 bloodª²gas in acute hypoxia dogs were observed dynamically through Swanª²Ganz catheter.RESULTS: After the acute hypoxia dogs breathed 950 mL/L O2,their heart rate (HR) slowed,their oxygen saturation (SaO2),arterial partial pressure of O2 (PaO2) and the arterial partial pressure of CO2 (PaCO2) increased,and the mean pulmonary arterial pressure (mPAP) decreased.Significant difference was found compared with those before breathing 950 mL/L O2(P<0ª±001-0ª±05).After the dogs breathed 30 mL/L CO2,their HCO3- and arterial partial pressure of CO2 (PaCO2 ) improved(P<0ª±001-0ª±05),but no marked changes were observed in the SaO2,PaO2 and mPAP.After the dogs breathed a mixture of carbon dioxide/oxygen,both hemodynamics and bloodª²gas were improved(P<0ª±001-0ª±05).CONCLUSION: Our results show that the combination of CO2 and O2 has a synergistic effect and the combination is better than CO2 or O2 alone,which can be used in the management of AMS. ......