The DLCOsb is one of the most common and widely tests clinically used across the world in pulmonary function laboratories to assess gas exchange from the lung to hemoglobin in the pulmonary circulation. This test is used in the differential diagnosis of respiratory related symptoms, to grade the degree of severity in lung disease, and to objectively monitor the progression of disease or the response to therapies. Therefore, it is important to have standard methods of performing and interpreting this test.This is a prospective study, collecting data from subjects at different simulated altitudes. The study hypothesis is that increasing altitude will increase the DLCOsb in a predictable manner that will allow for mathematical corrections to be applied for uniform interpretation in pulmonary labs at differing altitudes.
