I have emphysema, I m on oxygen 24/7, while traveling in Colorado at the eisenhower tunnel, my enogen oxygen stopped working and I lost concenciousness, my daughter did cpr and brought me back ang called an ambulance and ai was taken to hospital in Lakewood, Co. the put me on a bipap and kept me overnight. Now I m back in Texas where the altitude is lower but even when my oximeter reads 97 and heart 88 I feel so weak and shakey, what could it be, I feel such anxiety?