difference between asthma, copd, emphysema on PFT

• related: PFT and lung functions
• tags: #permanent #pulmonary

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• normal spirometry, abnormal methacholine challenge, and then response to albuterol: asthma
• baseline obstruction, near normalization after bronchodilator: asthma
• baseline obstruction, no significant change after bronchodilator: COPD
• normal spirometry, CT showing emphysema: emphysema¹

Patients with asthma may develop increased compliance of the lungs consistent with emphysema despite the absence of a history of smoking. These patients are among the group classified as having the asthma-COPD overlap syndrome. Abbreviation: TLC, total lung capacity.^{2 3}

Links to this note

• PFT and lung functions
  • difference between asthma, copd, emphysema on PFT

Footnotes

1. An Algorithmic Approach to Chronic Dyspnea ↩

2. SEEK Questionnaires ↩

3. Gelb AF, Yamamoto A, Verbeken EK, et al. Unraveling the pathophysiology of the asthma-COPD overlap syndrome: unsuspected mild centrilobular emphysema is responsible for loss of lung elastic recoil in never smokers with asthma with persistent expiratory airflow limitation. Chest. 2015;148(2):313-320. ↩