Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP single view of the chest has been obtained with patient in semi-upright position . Analysis is performed in direct comparison with the next preceding similar study of ___ . Position of previously described right - sided subclavian central venous line and left - sided PICC is unchanged . As before , there is mediastinal shift towards the left hemithorax which now is completely opacified , demonstrating complete loss of aeration of the left lung . This finding occurring in combination with left - sided mediastinal shift is highly suggestive of central airway obstruction which is probably accomplished by mucus plugs . There is no evidence of new pulmonary infiltrates in the right lung ; however , the vascular pattern suggests some degree of congestion with possible mild increase of pleural effusion , now partially obliterating the diaphragmatic contours .
    OUTPUT:
    
Complete opacification of left - sided hemithorax in the presence of mediastinal shift towards the left . Clearing of central airways recommended . Referring physician , ___ was paged at 4 :45 p .m .