Pleural Effusions and Thorascopy

Coders occasionally make the mistake of coding pleural effusions as a PDx; however, a cursory review of the medical literature will document that a pleural effusion is almost always integral to the underlying disease, and is usually addressed only by treatment of that condition. In these cases, it should not be coded. (Presumably, if the underlying condition is not determined, but there is evaluation and treatment, and it is the sole reason for admission, it may be coded as principal. This would, however, be extraordinarily rare.)

So, when may you code the pleural effusion as a secondary diagnosis?

• If the effusion is addressed separately, with additional diagnostic studies such as decubitus X-ray or diagnostic thoracentesis. The effusion may be treated by therapeutic thoracentesis (chest-tube drainage).
• It is appropriate to report pleural effusion (J91.8) as an additional diagnosis when the condition requires either therapeutic intervention or diagnostic testing. A code is assigned first for the underlying condition, followed by code J91.8, Pleural effusion in conditions classified elsewhere.
• Pleural effusion noted only on an X-ray report is not reported. The issue of thorascopic intervention raises another teaching point –

• Therapeutic thoracoscopic drainage of pleura/ pleural cavity (example 0W9B4ZZ, left side) results in change to a surgical DRG with an increased case weight; if thoracoscopic drainage is diagnostic only (0W9B4ZX, left side) the DRG is not affected.
• Thoracoscopy with excisional biopsy of pleura (0BBP4ZX) or bronchus also changes the DRG to a surgical one; diagnostic aspiration (extraction), brushing or drainage of bronchus, (0BDB4ZX, left side for example) or lung (0BDB4ZX, left side) does not.
  So, look carefully at the op reports when reviewing a thorascopic procedure.