RESPIRATORY HEALTH SCREENING USING PULMONARY-FUNCTION TESTS AND LUNG SOUND ANALYSIS

Lung sounds (LS) analysis is a potential source of additional objectiv e, noninvasive and quantitative information on the status of the pulmo nary system. We have examined the hypothesis that the addition of lung sounds analysis to spirometry increases the sensitivity of objective population screening, as compared to the use of spirometry alone. Ques tionnaires, spirometry and lung sounds were obtained in 493 active wor kers. Lung sounds analysis consisted of the averaged power spectra of breath sounds, measured separately during inspiration and expiration a t four standard locations over the trachea and the chest-wall. Of the 493 subjects, 91 had an obstructive lung disease, including 27 with ch ronic bronchitis identified by a history of prolonged cough and sputum production but with normal spirometry. Twelve additional workers had a restrictive lung disease. Abnormal spirometric results were found in 74 of the patients. Abnormal lung sounds analyses were found in 54 pa tients, including 14 of the chronic bronchitis cases, so that the over all sensitivity of objective screening tests increased from 71% to 87% by combining the two tests. Thirty three of the subjects considered n ormal by evaluation of their questionnaire and spirometry had abnormal lung sounds. Of the twenty four who were re-evaluated 12-18 months af ter the first tests, three had developed a lung or heart disease. We c onclude that the combination of spirometry and lung sounds analysis si gnificantly increased the sensitivity of detection of pulmonary diseas es by objective tests, and provided an early sign of lung disease that was not detected by spirometry alone.