A 13 years old boy from Melbourne couldn't use his nose to breathe for six years due to too much mucus in his lung. It's tough to play most sports under this condition.
When I tested him in the blood oxygen machine, his blood oxygen level was only 50, and his heart rate was around 96. The device is beeping almost during the whole session.
After the treatment, the blood oxygen machine shows the oxygen blood saturation level becomes 99, and the heart rate becomes 68. He also uses his nose to get some air as well. He can breathe so much easier than he came in.