Diagnosing disorders of respiratory mechanics in refractory workers

Abstract

Introduction. The current decrease in occupational exposures complicates expert examination of the link between job and disease, thus requiring the use of more sensitive and high-tech diagnostic techniques. In addition, a low incidence rate of occupational diseases against the background of poor working conditions indicates a possible increase in the incidence of “hidden” occupational diseases mimicking common non-communicable diseases. The purpose of our study was to assess the respiratory function in refractory workers using body plethysmography and measurements of the diffusing capacity of the lungs. Materials and methods: One hundred six male workers aged of 45.62±0.8 years, all engaged in refractory manufacturing for the average of 15.5±0.88 years and at risk of dust-related respiratory diseases, were examined in our Occupational Health Center within the regular health check-up. Results. The results of body plethysmography (a pulmonary function test) showed a decrease in the FEV1/FVC ratio, i.e. the ratio of the forced expiratory volume over the first one second to the forced vital capacity of the lungs, to the group average of 77.87±0.76% of the normal value. We also observed increased bronchial resistance during exhalation and total bronchial resistance in 65% and 50.9% of the workers, respectively. We registered a decreased transfer factor in the examined subjects with the group average of 73.9±1.37%. Neither chest X-ray nor CT scan showed significant changes in most of workers. Signs of emphysema were registered in 5.7% of those examined cases. No significant differences in the prevalence of obstructive disorders were found between smoking and non-smoking workers. Bronchial obstructive syndrome in combination with impaired pulmonary gas exchange and respiratory muscle fatigue was registered in 16 workers (15%), thus necessitating specific therapy to interfere with disease progression. Limitations. Our findings cannot be extrapolated to the workforce as a whole, since only men included in the study cohort. Conclusions. Indicators of the diffusing capacity of the lungs, which simultaneously reflect both pulmonary ventilation and perfusion, in combination with findings of body plethysmography and chest CT scan, can provide important information about functional changes in the respiratory system. Early diagnosis of bronchial obstructive syndrome allows timely beginning therapy and prevention of disease progression.