This test is designed to determine whether you have something called a pulmonary shunt. This is a
condition where blood vessels bypass your lungs and the blood is not properly oxygenated. This
results in a lower than normal level of oxygen in your blood.

What is involved?

Before the test starts we will take a small amount of blood from your wrist. During the test you will be sitting down, you will breathe 100% oxygen from a tube much like a snorkel whilst wearing a peg on your nose. You will breathe the 100% oxygen for 20 minutes. At the end of the test we will take a second blood sample from your wrist.

What happens after the test?

After the test your consultant will review the results and decide whether you have pulmonary shunt.
The results of the test will be fed back to you at your next clinic appointment.