Pulse oximeters are very useful for telling us when you don’t have enough oxygen in the blood. Some people desaturate with exercise. Some people desaturate when they sleep. One of the things we measure in Pulmonary Rehab is saturation at rest, with exercise, and then recovery (how long it takes for your heart rate and oxygen levels to return to normal).
Many people with COPD and ILD are fine at rest, but as soon as they walk across the room, their oxygen levels decrease. You may have had a 6 minute walk test at your doctor’s at some point. We use this information to titrate, or adjust your oxygen flow levels while you exercise. Without enough oxygen, your cells can’t function. Your muscles get very tired very quickly, and you have to stop and rest. Your heart compensates for the low oxygen by beating harder and faster. You may even feel faint.
In a 6 week formal Pulmonary Rehab program, we ask patients to measure 2 things with each exercise: breathlessness, and how hard were they working their muscles to do the exercise. Think of 30 minutes of window shopping at the mall vs. 30 minutes of walking in your neighborhood, without stopping to chat with anyone. We put these 3 things together to titrate your oxygen flowrate. At the end of the program, many graduates want to know where to buy their own pulse oximeter.
Here is what I tell my patients: I want THEM to be able to tell when they need to slow down, stop, or turn up the oxygen. Not a machine. After 6 weeks they are usually pretty good at determining when they are working too hard. So I discourage them from buying one. Towards the end of the program, we play a little game: without looking, I have them guess what their Heart Rate and Saturation are after each exercise. By graduation day, they are generally right on. So if you must, and you feel safer, by all means get one.
If you have no idea what your usual heart rate and oxygen levels are, then I recommend you get one. I will talk about which ones are best in a later post. If you’ve never had an oxygen test of any kind that you can remember, and you feel breathless with any walking or exercise, ask your doctor to please do a walking test. If you don’t have a regular doctor or pulmonologist, and you want to start exercising, then I will recommend you get one for safety reasons.