Pulmonary collapse

This code represents atelectasis, a condition characterized by the partial or complete collapse of a lung or a lobe of a lung. It occurs when the alveoli, the tiny air sacs in the lung, deflate or are filled with fluid, preventing gas exchange.

Use this code when documentation explicitly states pulmonary collapse or atelectasis. This often occurs post-operatively, due to airway obstruction (e.g., mucus plug, foreign body), or from external compression (e.g., pleural effusion, pneumothorax). Supporting documentation should clearly identify the presence of collapsed lung tissue.

• Do not use this code for pneumothorax; a separate code exists for that condition.
• Consider if the atelectasis is acute or chronic, and if a more specific ICD-9 code is available based on the cause.
• Always sequence this code after the underlying cause if known and documented (e.g., post-operative complication, foreign body in airway).