Effects of prebreathing oxygen-rich gases on denitrogen from body under quiet sitting and exercise states

Abstract

Objective To study the denitrogen regularity of human body when prebreathing different oxygen-rich gases and to promote denitrogen effects of preventing altitude decompression sickness denitrogen.Methods Seven healthy male subjects,aged from 18-20 years old,respectively breathed 60％,70％,80％,90％ oxygen-rich gas and pure oxygen under quiet sitting and exercise state.The expiratory gas was collected to a bag and oxygen concentrations were detected in open condition.The pulmonary ventilation volume and heart output volume were measured by MP150 system.Exercise state was the bicycle cycling with 40 W load.All results were self compared.Results The denitrogenation of breathing 60％,70％,80％ and 90％ oxygen-rich gases was correspondingly equivalent to the effects of 59.31％,72.81％,76.45 ％,84.18％ oxygen-rich gases and pure oxygen breathing.Different concentration oxygen-rich gases breathing caused different denitrogen effects in exercise state.Comparing with the breathing of 80％-90％ oxygen-rich gases under exercise,breathing 60％ and 70％.oxygen-rich gases enabled more denitrogen effects by increasing 45 ％ and 12 ％ respectively.Conclusions Whole body exercise provides enhanced nitrogen washout from tissues during the oxygen prebreathing because of the improvement of respiratory and circulatory functions.The lower oxygen concentration prebreathing,the more effective denitrogenation got from exercise. Key words: Decompression sickness; Oxygen; Nitrogen; Motor activity