Why Short Of Breath While My Oxygen Level Stays The Same?
Short of breath with no change In oxygen saturation?
Dear Dr. Mahler:
I am confused – Why am I short of breath when I do various daily activities? My oxygen level doesn’t change at all when I check it. This has been going on for quite a while now.
My COPD was diagnosed 3 years ago, and I take Anoro inhaler in the morning. Previously, I was taking Bevespi inhaler, but my insurance company had me change to Anoro. The nurse at my doctor’s office has coached me on how to use the inhaler correctly. I completed a pulmonary rehab program at the local hospital, and I go to the community center 3 to 4 times a week – walking on the treadmill and pedaling on the bicycle.
What are your thoughts?
Sincerely,
Jane from Yuma, AZ
Dear Jane,
You question is common and can be confusing to many with COPD. First, it is important to understand that a low oxygen level can cause shortness of breath. However, an individual can have difficulty breathing even though the oxygen saturation (as measured with a finger oximeter) doesn’t change.
Most likely, your shortness of breath is due to what is called “dynamic hyperinflation.” Hopefully he following explanation can make this concept easy to understand. The figure below represents this process.
Measures of ventilation during exercise. Top figure (a) is what happens normally. Bottom figure (b) is what happens in someone with COPD.
A person with normal lungs (top figure) is able to take deeper breaths while inhaling and exhaling more. The downward arrow next to EELV (end-expiratory lung volume) reflects getting more air out. A person with COPD (bottom figure) is unable to exhale more (get all the air out) as shown by upward arrow next to EELV.
As a result, air is trapped in the lungs which pushes the diaphragm muscle down. This makes it harder to breathe. The process whereby air is trapped in the lungs is called “dynamic hyperinflation.” The word dynamic refers to with activities (as opposed to at rest) and word hyperinflation refers to too much air in the lungs. More detailed information is available in a review article written by Dr. Denis O’Donnell from Queen’s University.
Jane – anything that makes you breathe faster can lead to air being trapped in the lungs. Exercise, anxiety, and a chest infection or flare-up are common examples.
One way to slowing down the breathing rate and empty more air out of the lungs is with pursed-lips breathing.
Pursed-lips breathing
Bronchodilators such as Anoro (which you are taking), exercise training (which you are doing), and oxygen IF a person qualifies for its use can slow down breathing and reduce dynamic hyperinflation. Inspiratory muscle training is another treatment that can strengthen the breathing muscles and make it easier for someone to breathe.
I hope that this explanation is helpful. It is important to stay active and up-to-date on flu and pneumonia vaccines.
Please note, the advice provided is not a substitute for asking your health care professional about your specific situation.
Sincerely,
Donald A. Mahler, M.D.