Diagnostic Approach for Lung Hyperinflation

Initial Diagnostic Workup

Complete pulmonary function tests, including spirometry, static lung volumes, diffusion capacity, and arterial blood gas analysis, should be performed to fully document the physiologic status, as recommended by the European Respiratory Society and the American Thoracic Society 1, 3
Assessment of airflow obstruction through FEV1/FVC ratio is critical, with values <70% suggesting obstructive lung disease, according to the American Thoracic Society 2
Measurement of total lung capacity, residual volume, and RV/TLC ratio to quantify the degree of hyperinflation, as suggested by the American Thoracic Society 3
Diffusing capacity assessment provides important information about gas exchange, as noted by the American Thoracic Society 3

High-Resolution CT Scan (HRCT) can help differentiate between structural abnormalities causing airflow limitation and estimate the degree of emphysema, as recommended by the European Respiratory Society and the American Thoracic Society 1, 2
HRCT can identify bronchial wall thickening, detect gas trapping, and estimate the degree of emphysema, according to the European Respiratory Society and the American Thoracic Society 1, 2

For suspected COPD, assess smoking history, occupational exposures, and family history of lung disease, as recommended by the European Respiratory Society and the American Thoracic Society 1, 2
Consider alpha-1 antitrypsin deficiency testing, especially if emphysema is predominantly in lower lobes or onset is at a young age, as suggested by the American Thoracic Society 3
Evaluate for comorbidities, including cardiovascular disease, which is common in COPD patients, according to the European Respiratory Society 1

Cardiopulmonary exercise testing can be valuable to assess functional limitation and oxygen desaturation with exertion, as recommended by the European Respiratory Society and the American Thoracic Society 1, 3
Six-minute walk test to evaluate functional capacity and need for supplemental oxygen, as suggested by the European Respiratory Society 1
Consider polysomnography if symptoms of sleep-disordered breathing are present, as recommended by the American Heart Association 6
Ventilation/perfusion scanning should be considered if pulmonary embolism is suspected as a cause of unexplained dyspnea, as suggested by the Journal of the American College of Radiology 5
Echocardiography to assess for right ventricular enlargement and estimate pulmonary artery pressure, as recommended by the American Heart Association 4, 5