Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Single portable semi-erect chest radiograph was obtained . Since the prior exam at 6 :00 a .m . , rightward mediastinal shift has significantly increased . There is increased atelectasis in the right middle lobe and partial collapse of the right lower lobe . A vague opacity projecting over the bronchus intermedius may represent a mucus plug . A tracheostomy tube is in stable position . An enteric catheter extends inferiorly off the edge of the film . The left lung is clear .
    OUTPUT:
    
Rightward mediastinal shift secondary to right middle and lower lobe volume loss . Bronchoscopy should be performed to assess for and treat potential mucus plugging in the bronchus intermedius .