Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable AP semi-erect chest film ___ at 20 :33 is submitted .
    OUTPUT:
    
Interval extubation and removal of the nasogastric tube and mediastinal drain . The right internal jugular central line is unchanged in position . Stable postoperative cardiac and mediastinal contours status post median sternotomy for CABG . Layering left effusion with patchy retrocardiac opacity most likely reflecting atelectasis , although pneumonia or aspiration can not be excluded . No pulmonary edema . No pneumothorax .