Interstitial emphysema and related conditions

This code represents the presence of air within the interstitial tissues of the lung, outside of the normal alveolar spaces. This can occur due to barotrauma, trauma, or underlying lung disease, leading to air dissection along bronchovascular sheaths. It signifies a condition where air has abnormally escaped into the connective tissue of the lungs.

Use this code when documentation indicates interstitial emphysema, pneumomediastinum, or subcutaneous emphysema originating from a pulmonary source. This is often seen in neonates on mechanical ventilation, patients with severe asthma, or following chest trauma. Supporting documentation would include imaging reports (e.g., chest X-ray, CT scan) confirming air in the interstitial spaces.

• Differentiate from subcutaneous emphysema not originating from a pulmonary source, which would be coded elsewhere.
• Always look for the underlying cause of the interstitial emphysema, as it may require additional coding.
• Do not confuse with pulmonary emphysema (e.g., COPD), which involves alveolar destruction, not interstitial air.