Features of human capillary blood flow on breathing by heated helio-oxygen mixtures

The purpose of the study: to assess the features of microcirculatory blood flow.
Materials and methods. A comparative assessment of microcirculation by laser Doppler flowmetry was carried out in 19 male volunteers aged 20–25 years against the background of breathing heated to 40° C oxygen-nitrogen and helium-oxygen gas mixtures.
Main results. Breathing with a heated oxygen-nitrogen mixture consisted in an increase (by approximately 25–35%) of the values of the integral indicator of microcirculation against the background of a decrease in its efficiency. Switching to breathing with a heated helium-oxygen mixture «HeliOx 25/75» in all examined persons also led to an increase in the volumetric velocity of the peripheral blood flow. However, the degree of increase in the indicator (by 35–45% compared with normal breathing conditions) turned out to be significantly more pronounced than it was during breathing with a heated oxygen-nitrogen mixture. In addition, when breathing «HeliOx 25/75», starting from about the 2^nd minute of breathing, an increase in the efficiency of microcirculation was observed due to an increase in the «contribution» to the blood flow reaction of its «active» (neuromyogenic) components.