The management of the lungs during cardiopulmonary bypass.

Many factors that contribute to the postextracorporeal pulmonary insufficiency have been recognized over the years that extracorporeal circulation has evolved. It is evident that more than one factor is the cause. For the present, a complex multifactoral problem appears to exist. Whether the unifying theory for this syndrome is related to abnormal organ perfusion, blood element destruction, microvascular phenomenon secondary to release of vasomotor substances or a combination of these remains to be determined. It is clear that all patients who undergo cardioplumonary bypass sustain some degree of pulmonary injury. Most lungs provide ample reserve, and adequate postoperative pulmonary care is sufficient to avoid morbidity related to the lungs. However, patients with severe forms of cardiopulmonary disease who require cardiopulmonary bypass require intraoperative pulmonary care as discussed herein to preserve maximum pulmonary function during the postoperative period.