Abstract

Patients after operation are often nursed with the foot of the bed raised in order to facilitate drainage of blood from the legs and of secretions from the trachea. Measurements of the changes in lung volume, of the oxygen cost of breathing, and of the movements of the rib cage and abdomen in the sitting, supine, and 15 degree head-down positions have been made in three subjects. The subjects selected were one overweight, one of medium, and one of lean body build. The oxygen cost of breathing was considerably increased in the head-down position in the overweight subject, less so in the one of medium build, and not at all in the lean subject. The cause of the increased oxygen cost of breathing and of its influence on the position in which patients are nursed after operation is discussed.