Pleural effusion is a typical disorder that is seen in patients who have congestive heart failure. It is an abnormal accumulation of fluid within the pleural space. If the physician completes therapeutic intervention or diagnostic testing for the pleural effusion, then it is acceptable to report it as a secondary diagnosis. If the physician does NOT specifically evaluate or treat the pleural effusion separately from the congestive heart failure, then it should NOT be reported as a secondary diagnosis.
The pleural effusion is an acceptable secondary diagnosis because of the additional x-ray to assess the volume.