FOT and COPD: Understanding Airway Mechanics Beyond Spirometry
In COPD, Forced Oscillation Technique (FOT) measures airway resistance and reactance during normal tidal breathing, revealing mechanical changes in the small airways and lung elasticity that spirometry can miss or only detect once disease has progressed significantly. Because COPD often begins with damage to the small, peripheral airways the part of the lung spirometry is least sensitive to — oscillometry has become a growing area of clinical interest for earlier detection and more detailed monitoring of the disease. This article explains why COPD is, in some respects, a difficult disease for spirometry to catch early, what FOT adds to the picture, and how the two methods work together in practice. Why COPD Is Hard to Catch With Spirometry Alone Chronic Obstructive Pulmonary Disease is, at its core, a disease of the small airways and lung tissue — long before it becomes a disease of the large airways that spirometry is best at detecting. Spirometry measures forced expiratory vo...