Acute episodic asthma, which is totally reversible, is not included in the COPD designation. Many of these individuals are women and a substantial proportion are nonsmokers or individuals who have smoked only a small amount. By contrast, if major smoking is present and markers of reactions, ie, IgE and eosinophilia are not present, the designation chronic bronchitis is most commonly used, particularly where hyperinflation is not present. The designation of emphysema refers to patients who are almost invariably smokers and show hyperinflation with little reversibility in response to inhaled bronchodilators. Abnormalities of the air-blood interface as determined by the carbon monoxide diffusion test are more common in emphysema than in asthmatic or chronic bronchitis.
Overlaps are common.
Thus, knowledge of the age at which the FEV 1 is abnormal and the rate of decline over time are powerful indicators of premature mortality. When smokers stop smoking, the rate of decline of FEV 1 is dramatically slowed as emphasized in the Lung Health Study. By contrast, those who continue to smoke have more precipitous and continuous losses in FEV 1 . Whether baseline ventilatory function can be altered by the use of inhaled bronchodilators such as anticholinergics has been debated in the Lung Health Study. Although ipratropium improved airflow when it was used, no change in baseline occurred during a 5-year period.