Diagnosing disorders of respiratory mechanics in refractory workers

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.

Compliance with ethical standards. The study was conducted in compliance with the Declaration of Helsinki of the World Medical Association “Ethical principles for medical research involving human subjects” as amended in 2000 and the Rules of Clinical Practice in the Russian Federation approved by Order 266 of the Russian Ministry of Health dated June 19, 2003. Ethics approval was provided by the Local Ethics Committee of the Yekaterinburg Medical Research Center for Prophylaxis and Health Protection in Industrial Workers (protocol 10 of December 23, 2019).

Contribution:
Obukhova T.Yu. — study conception and design, analysis and interpretation of results, draft manuscript preparation;
Omelchenko O.G. — data collection, analysis and interpretation of results, draft manuscript preparation;
Budkar L.N. — study conception and design, analysis and interpretation of results, editing;
Gurvich V.B. — study conception and design, editing;
Plotko E.G. — study conception and design, editing.
All authors are responsible for the integrity of all parts of the manuscript and approval of the manuscript final version.

Conflict of interest. The authors declare no conflict of interest.

Acknowledgement. The study had no sponsorship.

Received: October 20, 2023 / Accepted: November 15, 2023 / Published: December 8, 2023