Radiographic pulmonary abnormalities after different types of cardiac surgery

Abstract

One aim of this study was to determine the incidence of new radiographic pulmonary abnormalities during hospitalization after cardiac surgery. Another aim was to determine if such abnormalities are more common among patients who had left internal mammary artery (LIMA) grafting. The predictive value of radiographic abnormalities for clinically important pulmonary morbidity was also determined. The anteroposterior chest radiographs of 152 patients obtained by portable equipment were evaluated to determine the incidence of new postoperative radiographic pulmonary abnormalities such as atelectasis, consolidation, infiltrate, and pleural effusion. Clinically important pulmonary morbidity was defined as a delay in tracheal extubation or discharge from the hospital because of a pulmonary reason. Among the 89 patients who had LIMA grafting and left pleurotomy, there was an 88% incidence of left-sided pulmonary abnormalities; a 73% incidence of left-sided atelectasis; and a 55% incidence of left-sided effusion. Among the 63 patients who had saphenous vein grafting only and/or valvular surgery, the respective incidences were 68%, 54%, and 35%, which were lower ( P ≤ 0.05) than those in the patients who had LIMA grafting. There was no significant difference in abnormalities between the saphenous vein grafting and the valvular surgery groups. The 35% incidence of left-sided pleural effusion when LIMA grafting and pleurotomy were not performed was unexpectedly high. There was no association between radiographic abnormalities and age, the duration of cardiopulmonary bypass, and the duration of aortic occlusion, indicating that cardiopulmonary bypass was not a primary etiology of these radiographic abnormalities. Among the patients who had LIMA grafting, pulmonary morbidity contributed to delayed extubation after surgery of one patient and delayed discharge from the hospital of three patients. Among the patients who did not have LIMA grafting, pulmonary morbidity delayed discharge of one patient from the hospital. In a large percentage of patients, chest radiography detected minor pulmonary abnormalities that were rarely associated with a worse clinical outcome after cardiac surgery. Radiographic abnormalities were significantly more common when LIMA grafting was performed.