Interpretation of Pulmonary Function Tests and Optimization of Inhalation Therapy

Spirometry, also called office-based pulmonary function testing, is a useful tool for diagnosis and classification of lung disease. Here, we outline a simple stepwise approach for interpretation of spirometry results. The first step is to determine the forced expiratory volume in a one second/forced vital capacity (FEV1/FVC) ratio. If airflow is limited, a bronchodilator is administered followed by reassessment. The next step is to determine whether FVC is low; an observed decrease in FVC indicates a restrictive patten. For patients with obstructive disease, inhalation medication is needed. Therefore, this review also describes the most appropriate inhalation device for each patient and the correct use of the device to maximize inhalation therapy benefits. (Korean J Med 2021;96:209-217)