My mother is 86 yrs old. She had to have a pace maker put in as an emergency about 3 weeks ago. She just came home from a rehabilitation center and now how excessive congestion and swelling. Please note she does have COPD but had transitioned off of o2 as her levels were staying above 97%. Her O2 levels are dropping into the 70%. She is completely out of breath even when talking. Also her ankles are swelling tremendously. THey did a test for blood clots and that was neg. I believe they will be bringing in oxygen today. What else can be done?