Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome (commonly abbreviated to ARDS) is a form of lung failure wherein an underlying respiratory disorder causes the build-up of fluid in the lungs, and a dangerous drop in the blood oxygen level.

Causes

Any disorder of the lungs is capable of culminating in ARDS. Common examples include:

·         Chest injury;

·         Inhalation of excess smoke, or toxic drugs;

·         Near drowning;

·         Pneumonia; and

·         Inhalation of food into the lung.

Disease pathway

When they are injured, small air sacs in the lungs (alveoli) are inundated with blood and fluid, leading to their collapse.

This interferes with the function of the alveoli, which involves the transfer of oxygen from inhaled air to the bloodstream. The result is a sudden fall in the oxygen concentration in the blood.

A decreased level of oxygen in the bloodstream can cause serious complications in other organs and systems. Multiple organ failure may occur.

Symptoms and diagnosis

In general, the symptoms of ARDS manifest within several days of the initial lung injury. These include:

·         Shortness of breath;

·         Wheezing, and/or quick, shallow breathing;

·         Blue discolouration of the skin (cyanosis);

·         Abnormal heart rhythms;

·         Lethargy; and

·         Depressed consciousness.

Upon analysis, an x-ray or scan of the chest will reveal fluid in regions that should normally be filled with air, while blood tests will indicate a below-average concentration of oxygen.

Treatment

Successful treatment for ARDS normally depends on identifying and addressing the underlying lung disorder.

Mechanical ventilation or oxygen therapy is usually also required. This involves the delivery of high-pressure air with above-average concentrations of oxygen; either through a mask, or with a tube inserted directly into the windpipe (trachea).