What is Adult (acute) Respiratory Distress Syndrome (ARDS)?

Adult Respiratory Distress Syndrome (ARDS) is a medical emergency, which results in pulmonary oedema (swelling caused by infiltration of serous fluid into lung tissue), which results in an inability to take up oxygen leading to severe respiratory failure followed by failure of other organs in the body as well.

What are the causes of ARDS?

Any acute process that directly or indirectly injures the lung can cause ARDS. In some cases, there may not even be a predisposing condition. Common causes include;

• Infection of the lungs i.e. Pneumonia
• Generalised infection (systemic sepsis)
• Aspiration of contents of the stomach into the lungs, near drowning, or inhalation of toxic agent
• Direct trauma to the lungs.
• Massive blood transfusion.
• Drug ingestion.
• Inflammation of pancreas (an organ lying below and behind the stomach that secretes hormones), known as pancreatitis.

What are the symptoms of ARDS?

Patients usually do not have previous lung disease. The timing of the onset of symptoms varies greatly and the patient may develop ARDS symptoms any time within 24-48 hours after the onset of the predisposing condition. Breathing difficulty occurs first. The skin may appear bluish, moist or mottled and may not improve with inhalation of oxygen. Patient may be agitated initially and later become lethargic or unconscious.

How is it diagnosed?

The doctor makes the diagnosis based on clinical findings. He will suspect ARDS if;

• Patient presents with breathing difficulty of sudden onset.
• The chest x-ray shows changes in both lungs suggestive of diffuse lung injury.
• On the basis of tests like arterial blood gas analysis-ABGs (estimation of levels of oxygen and carbon dioxide in the arterial blood) which may shows low levels of oxygen in the arterial blood indicating lung malfunctioning.

What is the treatment?

The patient should be taken immediately to the hospital where he/she will be admitted to the intensive care unit. Treatment consists of mechanical ventilation i.e. the patient is put on a machine which helps the patient breath. Along with this patient is also given specific treatment for the precipitating illness or injury.

What is the outcome?

ARDS is a very serious illness with a high mortality. Patients can die from widespread systemic infection or multiple organ failure. It is more commonly fatal for elderly people. Those who survive usually have a good outcome with minimal, if any, persistent lung symptoms. Survivors of severe cases may have permanent fibrosis in the lungs (formation of scar tissue) and consequently symptoms of restrictive lung disease.
What are the complications?
These may include

• Death
• Failure of multiple organs of the body
• Permanent lung disease

Written by Medpages Editorial Team
Last Editorial Review: 15/1/2010