Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable AP chest radiograph . Left - sided chest tube has been placed and the pneumothorax has resolved . The mediastinum is now appropriately situated . Lung volumes are low with bibasilar atelectasis . There is also small pleural effusion on the left , similar to 10 :21 a .m .
    OUTPUT:
    
Interval decompression of large left tension pneumothorax .