Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Bedside AP radiograph of the chest demonstrates improved aeration as well as persistent postoperative mediastinal widening . There is a persistent small left pleural effusion and associated left basilar atelectasis . The Swan - Ganz catheter has been removed , but the sheath remains in place . An endotracheal tube terminates no less than 5 cm above the carina . An orogastric tube terminates in the stomach , although this could be advanced by 2 - 3 cm to ensure that the side port is also beyond the gastroesophageal junction .
    OUTPUT:
    
Persistent small left pleural effusion and stable post-operative mediastinal widening .