Hyperinflation in asthma and emphysema. Assessment by pulmonary function testing and computed tomography

Chest. 1988 Aug;94(2):286-9. doi: 10.1378/chest.94.2.286.


To assess the role of emphysema on the hyperinflation in chronic asthma, we studied 20 subjects with irreversible airflow limitation. Ten of the subjects had asthma and had never smoked; the other ten were cigarette smokers. Pulmonary function testing and chest computed tomography (CT) scans were performed on all subjects. Emphysema was graded using a score based on the percentage of lung involved on CT scan. There was good inter- and intra-observer agreement for the emphysema scores. The median emphysema score was 0 percent in the nonsmoking group and 10 percent in the smoking group. All smokers with a total lung capacity (TLC) of greater than 120 percent predicted had evidence of emphysema on the CT scan. None of the asthmatic subjects with a TLC greater than 120 percent predicted had emphysema identifiable on CT scan. We conclude that chronic asthma with severe hyperinflation does not result in emphysema.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Asthma / diagnostic imaging
  • Asthma / physiopathology*
  • Chronic Disease
  • Emphysema / diagnostic imaging
  • Emphysema / physiopathology*
  • Female
  • Humans
  • Lung / physiopathology*
  • Male
  • Middle Aged
  • Pulmonary Ventilation
  • Respiratory Function Tests
  • Smoking
  • Tomography, X-Ray Computed