What can be the contributing factor for the fluctuations in oxygen saturation levels?

Hello doctor,

My mother is 97 years old. She had a minor heart failure with a B-type natriuretic peptide (BNP) of 110. Recently, she had a bad urinary tract infection (UTI) and asthma. Up to that point, her oxygen (O2) saturation levels without supplemental oxygen were 95 to 96. Now that she is recovering from UTI, her O2 levels are 97 to 98 with 0.53 gallons of supplemental O2 and her O2 level without supplemental O2 are between 88 and 92. All of these numbers are at rest. She does not do too much activity. What can be the contributing factor to this change? She had a chest CT scan and it did not show chronic obstructive pulmonary disease (COPD). Should she stay on the O2? It is somewhat of a hazard. The tubing is difficult for her to handle. We must have someone with her all the time even throughout the night. We are concerned if she gets up to use the bathroom her foot will get caught on the tubing. She had a complete blood workup done. All the results were normal except that she is anemic. Currently, she is using nebulizer given by the primary care physician containing Ipratropium, Levalbuterol, Budesonide and antibiotics for recurrent UTI.

Thank you doctor,

My mother went into the hospital with the urinary tract infection (UTI). I asked for a blood culture, but it was not done. Yes, she had pre-existing asthma. But, it seemed to act up last month only. In the summer and spring, she was fine. We had done an allergy test and also air quality tests were done in our home. They did an echo and her ejection fraction was 55. She is now monitored closely by her primary care physician at home. We do urine cultures as well as analysis quite frequently because of the recurring condition. There is no sign of pulmonary embolism. I asked the pulmonologist at the hospital who reviewed the computed tomography (CT) scan. I mentioned to the pulmonologist that I thought she might have had bronchitis but he abruptly said no. I think the UTI sent her into a tailspin. Unfortunately, even though I asked them to do urine cultures at the hospital and continue the antibiotics they failed to do so. What do you think? Her saturation levels are improving so slowly. She tires easily even when her saturations are 98. Two years ago when she had another bad UTI, she was exhausted for quite a while but I never checked her O2 level. Please also let me know if you think whether she could be on the pulse oxygen as opposed to the continuous type. She was discharged from the hospital without any orders accept to follow up with her pulmonologist. The one she went to about 10 months ago has retired and the pulmonologist we want is not available until next month.