How Common Is Airflow Limitation in Patients With Emphysema on CT Scan of the Chest?

A Novel Spirometric Measure Identifies Mild COPD Unidentified by Standard Criteria

“…9,[14][15][16] Our findings, based on the examination of the largest smoker population with available quantitative CT scanning data, demonstrate the presence of structural lung changes before airflow obstruction becomes evident according to the FEV 1 /FVC ratio. We report, to our knowledge, for the first time that, in those with normal FEV 1 /FVC, low FEV 3 /FEV 6 is associated significantly with impaired CT scanning measures, shorter 6MWD, increased dyspnea perception, and lower respiratory quality of life.…”

“…12,13 Accumulating evidence suggests many current or former smokers have clinical, radiologic, and physiologic abnormalities not identified by means of currently used spirometric measures. 9,[14][15][16] The FEV 1 FVC ratio may remain within the normal range even after considerable airway damage has occurred. FEV 3 /forced expiratory volume in 6 s (FEV 6 ) and FEV 3 /FVC have been proposed as measures capable of detecting small airway disease and, hence, mild COPD manifestations.…”

Multicenter Study Comparing Case Definitions Used to Identify Patients with Chronic Obstructive Pulmonary Disease

“…Up to 40% of patients with radiographically evident emphysema do not have airflow obstruction when assessed using spirometry (27,28). Moreover, the FEV 1 /FVC ratio may fail to identify airflow obstruction in almost 10% of patients with mixed obstructive and restrictive pulmonary disease (29).…”

Is it time to move beyond the “O” in early COPD?

“…In a single centre analysis of patients who had a chest CT scan for evaluation of the lungs, 274 of 2125 patients had more than 5% emphysema. In that study, spirometry using the lower limit of normal failed to identify 13.9% of patients with emphysema and using the fixed ratio of FEV1/FVC <70% failed to identify 6.9% of patients with emphysema [18].…”