THE EFFECT OF LOW CONCENTRATIONS OF CARBOXYHEMOGLOBIN ON THE "ALTITUDE TOLERANCE" OF MAN

Abstract

By means of measuring a sensitive visual function, the critical flicker fusion frequency (FFF) which is impaired by mild anoxia (9,000 to 12,000 ft. pressure-altitude), the effect of small amts. of COHb has been studied at altitude. Increments in circulating COHb of the order of 5-10% resulted in appreciable deterioration of FFF at altitudes which alone did not affect the FFF (5,000 and 6,000 ft.).