Will I need to do anything to prepare for the test?
If your blood sample is taken from your wrist, your health care provider may perform a circulation test called an Allen test before taking the sample. In an Allen test, your provider will apply pressure to the arteries in your wrist for several seconds.
If you are on oxygen therapy, your oxygen may be turned off for about 20 minutes before the test. This is called a room air test. This won't be done if you are unable breathe without the oxygen.
