[Diffusion ability of lungs at advanced age]

Changes in lungs ventilation is mainly studied in the research on the features of respiratory system in ageing process. The condition of alveolar--capillary oxygen diffusion expressing the presence of central acinar lung emphysema is much less investigated. The purpose of the research was to study particularities of lung diffusion ability, which is considered to be one of the important mechanisms determining blood oxygenation in elderly. Results of the research and discussion. The dynamic of body surface changes is much less variable with age, than the dynamic of the lung diffusion ability. This is considered to be the reason of preservation of age differences of lung diffusion ability referred to 1 M2 of a body surface. There are two differences in dynamic of DLCO (diffusion lungs capacity) referred to total lungs capacity and referred to 1 M2 of a body surface. The indicator of double correlation of vital capacity of lungs (VCL) of elderly patients and Dlco makes +0.764; between intrathoracic gas volume and DLCO +0.654; between the residual volume of lungs (RV) and DLCO +0.729; between the Tiffno index and DlCO +0.654. The same parameters of young patients with COPD were 0.112; -0.245; 0.105; 0.312 correspondingly. Age related reduction of ratio of lungs diffusion ability to total lungs capacity is less prominent comparing to the ratio of DlCO body surface. The sex dependant differences of DlCO/TC smooth out in with each decade in contrast to DlCO/m2. A close correlation was revealed between DLCO and vital lungs capacity, the residual volume of lungs, intrathoracic gas volume and Tiffno indicator in elderly patients with COPD.