To find out if you need oxygen for your flight, you may need to undergo a fit-to-fly test to see if there are any contraindications for flying.
First, your doctor will take a blood sample from you to see if your oxygen levels are normal (blood gas analysis). If the oxygen level is already low at this stage, your doctor will advise you to bring oxygen on board the aircraft.
If your oxygen levels are normal, your doctor may still feel there is a risk and will ask you to be tested for an airline flight. The test involves inhaling air containing an amount of oxygen similar to that in an airplane through a face mask or mouthpiece for 20 minutes. The doctor accompanies the patient during the examination to monitor the patient’s reactions.
The oxygen level is measured using a device called an oximeter that has a light emitting diode that shines through your finger, ear, or forehead to measure the oxygen concentration. If the measurement shows that the oxygen level has dropped below the recommended limit, the doctor will stop the test and check the patient’s oxygen level with another blood test. If the test takes the full 20 minutes, your doctor will take another blood sample after the test to check your oxygen level.
If the amount of oxygen in your blood drops below the recommended limit, you will need oxygen during the flight.
The doctor will decide how much oxygen you need (flow rate) based on the test results and your general health. In other cases, you will need an additional test called titration. It involves performing a fit-to-fly test several times, inhaling different amounts of supplemental oxygen, to determine which flow rate helps restore blood oxygen levels to normal.
Your doctor will tell you how long the test results will remain valid. Until your health condition changes, your results should remain valid. If it changes (i.e. disease worsens, blood oxygen level drops), you will need to test again before the next flight. You can watch a video on the fit-to-fly test on the ELF website.