Pulmonology Coding Alert

Knowing the signs and symptoms of adult respiratory distress syndrome (ARDS) can help coders by allowing them more easily to identify diagnosis and treatment procedures when reviewing documentation.

ARDS results from a severe injury to most or all of both lungs. Although ARDS is not a specific disease, it is a lung dysfunction associated with several diseases, such as pneumonia, shock, sepsis and trauma. Patients with ARDS may have severe shortness of breath and almost always have respiratory failure.

Although the precise cause of ARDS remains unknown, the syndrome can come about in two ways. First is a direct physical or toxic injury to the lungs, such as aspiration, smoke or other toxic fumes, and severe bruising usually caused by a blow to the chest. Second is an indirect, blood-borne injury to the lungs for example, severe infection and certain types of drug overdoses.

At the onset of ARDS, most of both lungs are involved. When alveoli are damaged, some collapse or fill with fluid. Consequently, the lungs have difficulty absorbing oxygen.

Within one to two days, progressive interference with gas exchange can bring about severe respiratory failure. Over the next several days, the lungs fill with inflammatory cells. Formation of scar tissue (fibrosis), which can further interfere with gas exchange, begins after 10 days and can become quite extensive by the third week after onset.

ARDS consists of three stages:

1. Exudative stage: the accumulation in the alveoli of excessive fluid, protein and inflammatory cells. This stage occurs during the first two to fours days after onset of injury.

2. Fibroproliferative (or proliferative) stage: Connective tissue and other structural elements in the lungs multiply in response to the injury.

3. Resolution and recovery: The lungs reorganize and recover over the next six to 12 months (sometimes even longer), depending on the precipitating condition and the injury's severity.

Some experts maintain that there is a fourth stage, which encompasses the six to 12 months after onset when some patients have ARDS-related continued health problems. But the fourth phase is not completely characterized and still requires research.

Source: ARDS Support Center, http://www.ards.org.