Monitoring Your Breathing

Your medical team will begin monitoring your breathing even before you notice any respiratory symptoms. If you attend an ALS clinic, a respiratory therapist or nurse will ask about any changes you’ve experienced and perform one or more simple, noninvasive tests to measure your progression.

​Forced Vital Capacity (FVC) is the primary test used to evaluate the breathing of ALS patients. It measures how quickly you can expel air from your lungs.

The Maximum Inspiratory Pressure (MIP) test measures the strength of your inhale through your mouth. The Sniff Nasal Inspiratory Pressure (SNIP) test is the same as the MIP, but it measures your inhale through your nose, which can be helpful for bulbar patients who are unable to form a good seal around the mouthpiece.

Your team might also recommend a capnography study, which measures your oxygen and carbon dioxide levels as you sleep. This can alert your team early on if your diaphragm function is impaired. This study takes place at home, with a clip on your finger and a thin tube in your nose.

The results of these tests, along with the observations you share, will give your team the information it needs to recommend the best care and respiratory equipment for you. The results from these breathing tests will also provide the documentation your neurologist will need for Medicare, Medicaid, and private insurance to cover your respiratory devices.

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