Gas exchange readjustments in response to hypoxia and hypercapnia exposure in Magadan region military service draftees

Abstract

Our study identified gas exchange and external respiration characteristics during hypoxia and hypercapnia exposure in young men of the Magadan Region. Materials and methods. A comprehensive survey in young men of military age, 18-21 yr., permanent residents of the Russia’s Northeast, was conducted. A hypoxic-&-hypercapnic respiration test with no CO2 absorption was used. Before and after respiration, using indirect calorimetry method, we analyzed gas composition in exhaled air, external respiration variables, body energy expenditure at rest, respiratory quotient, ventilation equivalents for oxygen and carbon dioxide (Carbonic gas analyzer, Medgraphics VO2000 gas meter). Statistical data processing was performed with Statistica 7.0 package. Results. Significant post-respiratory dynamics in most indicators of gas exchange and external respiration was found. In response to hypoxia and hypercapnia effects, an increase in the energy consumption at rest, in minute volume of body temperature and pressure saturation, in carbon dioxide emission and oxygen consumption per minute was observed with significantly decreased oxygen utilization factor. Conclusion. Effects of hypoxic-&-hypercapnic test can be seen as pronounced readjustments in analyzed variables: intensed metabolism at the test peak and that reduced below baseline in the recovery period. In this case, breathing patterns are readjusted with pronounced increase in pulmonary ventilation and higher values in breathing depth in comparison with the baseline value at each stage of the recovery period, up to its 3rd minute.