Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable upright chest radiograph ___ at 17 :59 is submitted .
    OUTPUT:
    
Interval removal of the endotracheal tube and nasogastric tube . The patient is status post median sternotomy with valve replacements and stably enlarged cardiac contours . There are layering bilateral effusions with associated patchy bibasilar airspace opacities suggestive of atelectasis , although pneumonia or aspiration should also be considered . No evidence of pulmonary edema . Slightly lower lung volumes with crowding of the central vasculature . No pneumothorax . Postoperative changes in the upper to mid abdomen .