Lung Function Tests

Today I had what turned out to be my final set of lung function tests...

Spirometry (from the Greco-Latin term meaning "to measure breathing") measures how well the lungs exhale, and the machine used to test this is called a spirometer (see photo above). Spirometry reveals any degree of narrowing or obstruction of the airways - my results on this test have pretty much always been in the normal range.Lung volume measurement records the maximum amount of air the body can hold and helps determine the elasticity of the lungs and rib cage. The most accurate way to obtain this measure is using a body plethysmograph, a sealed, transparent box (see above) that looks like a phone booth and determines the volume of gas in the lungs. An abnormally low reading indicates a stiffness that is common in restrictive lung disorders, such as scarring of the lung tissue (which can be a side effect of chemotherapy) where a person cannot inhale a normal volume of air. My results on this test have been slightly above average, which a common in those people like me with mild asthma.

Testing the diffusion capacity of the lungs permits an estimate of how efficiently the lungs are able to transfer oxygen from the air into the bloodstream. This is measured by testing the volume of carbon monoxide a person breathes out after a known volume of the gas has been inhaled. This is the test that for me has been way below average, right from before the chemotherapy. However, today the results continued to show improvement, and my diffusion capacity is finally within the low average range. The pulmonary doc said these numbers should continue to improve over the next six months. He also cleared me for flying without having to take extra oxygen (a real pain!) so that means I can fly starting in November with a short trip to Melbourne then a longer trip to San Fransisco to see my Mom and my sister Joann!

Unfortunately, my mouth had been in increasing pain over the last day or so, and I went and had the day oncology people look at it. They diagnosed oral thrush (a fungal infection of the lining of the mouth), a cumulative side effect of the chemotherapy. Fortunately it is easily treated with medication, but not as humorous as the drawing below...