Atelectasis Is a Major Cause of Hypoxemia and Shunt after Cardiopulmonary Bypass 

Abstract

Atelectasis is produced to a much larger extent after CPB than after anesthesia alone or with sternotomy and it explains most of the marked post-CPB increase in shunt and hypoxemia. Surgery per se contributes to a lesser extent to postoperative atelectasis and gas exchange impairment.