Measures of small airways disease as predictors of chronic obstructive pulmonary disease.
Occup Med: State of the Art Rev 1993 Apr; 8(2):375-395
The relationship between small airways abnormalities as determined by pulmonary function testing and the development of chronic obstructive pulmonary disease (COPD) was discussed. The pathophysiology of COPD was reviewed. Studies have found that 1 second forced expiratory volume (FEV1) and vital capacity (VC) decrease progressively over time and the decrements can be correlated with the onset of symptomatic disease. Histomorphometric studies have suggested that inflammation and narrowing of the small airways may be the earliest manifestation of smoking related COPD. Epidemiological studies in workers have shown that chronic airflow restriction and COPD can develop in a variety of occupations independently of smoking. Techniques for evaluating small airway function were described. These consisted of spirometry, single breath nitrogen dilution curve analysis, and manometric lung compliance studies. Spirometry has been the most widely used technique. It has been applied to measuring FEV1 and VC in cross sectional and longitudinal studies of the effects of smoking and exposure to raw farm products, chemicals, and dusts. Selecting a small airways function test to detect COPD was discussed. The single breath nitrogen dilution test can reliably differentiate smokers from nonsmokers; however, the technique requires a fully equipped pulmonary function test laboratory and gas sources. Because spirometric equipment can be easily employed in the workplace, spirometry was the method of choice for workplace screening for small airways disease. Methodological considerations for small airways dysfunction screening in the workplace were discussed. Spirometry appears to be the most appropriate technique for screening worker populations for incipient COPD.
NIOSH-Publication; NIOSH-Grant; Occupational-medicine; Pulmonary-function-tests; Epidemiology; Medical-screening; Respiratory-system-disorders; Airway-obstruction; Cigarette-smoking
Environmental Sci & Physiology Harvard School of Public Hlth 665 Huntington Ave Boston, MA 02115
Occupational Medicine: State of the Art Reviews. Spirometry