HEMODYNAMIC MECHANISMS OF CLINICAL EFFECTS OF CYCLIC STAY OF A HUMAN IN NORMOBARIC HYPOXIC ENVIRONMENT

Abstract

Purpose: in order to assess the adaptive hemodynamic responses formed in humans during cyclic stay (daily, for 2 hours, 15 sessions in total) in normobaric hypoxic gaseous environment with oxygen content in nitrogen of 15% (NHGE-15).Materials and methods: a study has been conducted with participation of 12 male test subjects aged 25-52. In course of cyclic stay in NHGE-15, systemic and cerebral blood flow parameters were evaluated in the test subjects.Results: in response to stay in NHGE, at the initial stage of the testing procedure, the test subjects showed hyperkinetic systematic circulation reactions: cardiac acceleration, increase in systemic blood pressure and cardiac output, with decrease in peripheral vascular resistance. At the same time, an increase in blood flow to cerebral vessels and hypersthenia in major cerebral vessels were revealed. Further stay in NHGE-15 was accompanied by a statistically significant reduction in severity of the above responses reflecting a gradual decrease in «stressfulness» of hypoxic effect due to formation in the body of primary adaptational structural and functional alterations in oxygen transport systems, regulatory and plastic processes. The fact of systemic and regional hemodynamics parameter optimizing was also revealed, recorded under normal conditions of gaseous environment, in course of the cyclic hypoxic impact.Summary: hypoxic exposure on the human body leads to centralization of the circulatory system, aimed at the maintenance of oxygen supply of vital organs. The result of hypoxic training is to reduce the severity of the reaction by increasing the reliability of functioning of the system of hemodynamics and its regulatory mechanisms.

Keywords

• normobaric hypoxic gaseous environment
• hemodynamic responses