Compensatory emphysema

Compensatory emphysema refers to the hyperinflation of healthy lung tissue in response to a loss of volume or function in another part of the lung. This occurs when an area of the lung is removed, collapsed, or rendered non-functional, leading to the remaining lung tissue expanding to fill the thoracic cavity and maintain gas exchange. It is a physiological adaptation rather than a primary disease process.

This code is appropriate for documenting the presence of compensatory hyperinflation of lung tissue, typically identified on imaging studies (e.g., CT scan, chest X-ray). It should be used when there is clear evidence of volume loss in one lung or lobe, and the remaining lung tissue demonstrates compensatory expansion. Documentation should specify the underlying cause of the volume loss (e.g., lobectomy, atelectasis, fibrosis).

• Do not confuse this with primary emphysema (e.g., due to smoking), which is coded differently.
• Always code the underlying condition causing the lung volume loss first, followed by this code as a secondary diagnosis.
• Ensure documentation clearly distinguishes compensatory hyperinflation from obstructive emphysema.