The effects of a short period of hypoxia on the ventilatory respone to carbon dioxide

grantor: University of TorontoIn the present study, a modified rebreathing technique was used to charactenze the ventilatory response to carbon dioxide before and after exposure to either 20 minutes of room air or hypoxia. The parametsrs measured included basal ventilation (Vb); the peripheral chemoreflex CO$\sb2$ threshold (Sp); the sensitivity of the peripheral chemoreflex to CO$\sb2$ (Sp); the central chemoreflex CO$\sb2$ threshold (Tc); the sensitivity of the central chemoreflex to CO$\sb2$(Sc) and the rate of rise of CO$\sb2$ due to subject metabolism (M). After room air esposure, none of Vb; Tp; Sp; Tc; Sc or M were significantly different than before. After exposure to hypoxia, however, neither Vb; Tp; Sp; Tc nor Sc were statistically different, but M was significantly lower than before. It is being suggested that this depression in metabolic rate induced by hypoxia may play a rols in the manifestation of hypoxic ventilatory decline.M.Sc