THE OXYGEN SATURATION OF HEMOGLOBIN IN THE ARTERIAL BLOOD OF EXERCISING PATIENTS

Abstract

Thirteen observations have been made during rest and after exertion on 9 patients suffering from a variety of pathological conditions. As a result of exercise, in 11 observations, there was diminished saturation of the hemoglobin in the arterial blood. In a patient with severe emphysema, the saturation fell from 78% to 23% with only slight exertion. In 5 of these 11 observations the O content of arterial blood remained stationary or was diminished in spite of an increase in O capacity. These results are directly opposed to those on normal individuals who, doing equal or greater amounts of work, have always shown an increased saturation of hemoglobin with O and a higher arterial O content, but are similar to those obtained with normal individuals doing much longer and more fatiguing amounts of work. The experiments indicate that in ill and debilitated individuals during exertion the volume of O diffusing through the pulmonary membrane is not enough to saturate the hemoglobin of the blood in the lungs. This suggests that the pulmonary mechanism may be a limiting factor in exercise[long dash]a factor which explains in part the inability of sick people to withstand exertion.