Pulmonary air embolism. Reappraisal of the importance in open-heart surgery.

Abstract

Experience with the use of extracorporeal circulation and advancement in surgical technique apparently has lowered the mortality and morbidity following operation for repairing a cardiac defect. Our early cases of open cardiac operation were carried out on beating hearts without occlusion of the pulmonary arteriy. It was customary to encounter the problem of the post-perfusion syndrome and it occasionally lead to unfortunate results. Since we have paid closer attention to the seperate occlusion of the pulmonary artery when the right heart was open, the respiratory complication and the so called post-perfusion syndrome were less often encountered. The presented experimental study was undertaken to determine the frequency of hemodynamic as well as pathological changes on the experimentally induced pulmonary air embolism in dogs. In the course of study, increased pulmonary arterial pressure and cardiac arrhythmia were noticed immediately after the injection of the air into the pulmonary artery, and lesion like interstitial pneumonia was observed later. Through the experimental and retrospective clinical study, it became clear that the prevension of the pulmonary air embolism is equally important as that of the systemic air embolism. Pulmonary' air embolism, like other pulmonary embolism, may cause similar hemodynamic alternation and pathological findings such as pulmonary hypertension, systemic hypotension, cardiac arrhythmia, pulmonary edema and lesion like interstitial pneumonia. These changes are found to be of degree and not of kind1>2>3>. In early cases of open cardiac operations performed on beating hearts without occluding the pulmonary artery so called post-perfusion lung syndrome and occasional fatalities were encountered. Although there have been extensive studies on this syndrome, the cause still remains unknown. In this report, importance of pulmonary air embolism in open cardiac surgery is stressed. From the data obtained on experimental studies and the clinical result, it is ;f;f\ £ ))2: (CHUNG-YUAN LIN) Received for publication August 23, 1967.