Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable semi-erect chest radiograph ___ at 05 :05 is submitted .
    OUTPUT:
    
Left - sided pacer , endotracheal tube , and nasogastric tube are unchanged in position . The heart is stably enlarged status post median sternotomy for CABG . Bibasilar airspace opacities with associated layering effusions may reflect compressive atelectasis , although pneumonia should also be considered . Interval improvement in mild but residual perihilar and interstitial edema . No obvious pneumothorax .