Acute respiratory distress syndrome (ARDS) is breathing failure, that can occur in critically ill persons with an underlying illness. ARDS is not a disease, instead it is a life-threatening condition that occurs when there is severe fluid buildup in the lungs. The fluid buildup prevents the lungs from functioning properly, preventing them from transferring oxygen from the air into the body, and carbon dioxide out of the body into the air.
In ARDS, the tiny blood vessels (capillaries) in the lungs or the air sacs (alveoli) are damaged because of an infection, injury, blood loss, or inhalation injury. Fluid leaks from the blood vessels into air sacs of the lungs. While some air sacs fill with fluid, others collapse. When air sacs collapse or fill with fluid, the lungs can no longer fill properly with air and the lungs become stiff. Without air entering the lungs properly, the amount of oxygen in the blood drops. When this happens, the person with ARDS must be given extra oxygen and may need the assistance of a breathing machine.
Breathing failure can occur very quickly, although it may take 1 or 2 days for fluid to accumulate. The process that causes ARDS may continue for weeks. If scarring occurs, this will make it harder for the lungs to take in oxygen and get rid of carbon dioxide.
In the past, only about 4 out of 10 people who developed ARDS survived. But today, with good care in a hospital’s intensive or critical care unit, many people (about 7 out of 10) with ARDS survive. Although many people who survive ARDS make a full recovery, some survivors have lasting damage to their lungs.