Pulmonary function testing is a valuable diagnostic method. In the diffusion test, the patient breathes mixtures of air containing small amounts of tracer gases such as carbon monoxide and helium.
Pulmonary function tests, or lung function tests, can evaluate heart and lung function and respiratory efficiency.
In a pulmonary function test, the patient inhales a lung diffusion mixture, which contains a small percentage of the tracer gas carbon monoxide. When the patient exhales, the composition of the patient's breath is analysed to determine how much of the carbon monoxide has been diffused through the lungs. The helium component of the lung diffusion mixture is used to determine the lung volume.
These tests are used in areas such as sports medicine, intensive care, neonatal care, rehabilitation and disability evaluation. They are also essential in the diagnosis of some disorders of the pulmonary, gastrointestinal, and cardiovascular systems.
Lung diffusion is reduced in diseases such as:
And is increased in cases of:
Another use of the lung function test gas mixture is calibration of this medical diagnostic equipment.