Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post median sternotomy and CABG . There has been interval increase in size of the left pleural effusion which is now large , and obscures assessment of the cardiac silhouette size . No pulmonary vascular congestion is identified , and there is mild rightward shift of mediastinal structures . The mediastinum is not widened . Left basilar compressive atelectasis is demonstrated . Right lung is clear . Trace right pleural effusion is slightly smaller compared to the prior study . No pneumothorax is identified . No acute osseous abnormalities are seen .
    OUTPUT:
    
Increased size of left pleural effusion which is now large with associated left basilar atelectasis . Trace right pleural effusion .