Acoustic and spirometric parameters of forced expiration in women under 9-day isolation in closed environment

Objective. The purpose of the study was to evaluate the pulmonary ventilation function in women in closed environment. The trial was conducted as a part of the isolation experiment «Moon - 2015». The study included spirometric testing and registration of forced expiratory noise (EN). The acoustic method is effective for the detection of obstructive changes in the lungs. Previously this method was used during 520-day isolation, under immersion and hyperbaric conditions. Materials and Methods. Six women aged 25-35 were examined during 9-day isolation. The control group consisted of 4 women aged 25-42. Women were examined twice before the isolation, on the 4th and 7th day of isolation and on the 3rd day after the isolation. Average environmental parameters corresponded to natural conditions. Vital capacity (VC), forced vital capacity (FVC), forced expiratory volume 1 (FEV1), peak expiratory flow (PEF), maximum expiration flow 50 (MEF50), and forced expiration flow (FEF25-75) were measured. The duration of tracheal sound recorded during forced expiration Ta was determined. The tracheal sounds were recorded via a microphone. The dynamics of indicators in isolation, and the correlation between spirometry and Ta were analyzed. Results. The main spirometric indices of all women were normal throughout the experiment. Slight decrease in FVC, FEV1, MEF50, FEF25-75 was observed on the 7th day of isolation. Decrease in FVC by 7 % was significant if compared to the control group. However, all changes were within normal variability range and of no clinical relevance. High correlation between Ta and FEV1/FVC ratio (Tiffeneau index) was revealed, which corresponded to the data of the previous experiments. In general, no bronchial obstruction was revealed during isolation. Conclusion. 9-day isolation did not lead to ventilation abnormality in women. The results obtained confirmed the efficiency of acoustic method for obstructive disorders control including extreme environmental conditions.