Abstract

Twenty-four patients undergoing cardiopulmonary bypass have been studied and the work of respiration was measured (1) before the incision, (2) before bypass with the thorax open, (3) after bypass, and (4) after suturing of the incision. Our results indicate that moving the thoracic wall requires 10 to 14% of the respiratory work and that little change occurs as a consequence of cardiopulmonary bypass.