Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP upright portable chest radiograph obtained . The right chest tube is unchanged in position projecting over the right lower hemithorax . There is no interval development of pneumothorax . There is a small right pleural effusion . Left lung is clear . Overall , heart size appears unchanged , though note is again made of a prominent hiatal hernia . The bony structures appear intact .
    OUTPUT:
    
Small right pleural effusion , but no pneumothorax status post chest tube to waterseal .