ARDS (adult respiratory distress syndrome)

Alternative names:

acute respiratory distress syndrome; congestive atelectasis; pump lung; shock lung; stiff lung

Definition:

A failure of the respiratory system characterized by fluid accumulation within the lung that causes the lung to stiffen. The condition is triggered by a variety of processes that injure the lungs. See also respiratory distress syndrome (infants).

Causes, incidence, and risk factors:

ARDS is a medical emergency. It may be caused by a variety of conditions that directly or indirectly cause the blood vessels to "leak" fluid into the lungs. The ability of the lungs to expand is severely decreased and damage to the air sacs and lining (endothelium) of the lung is extensive. Blood concentration of oxygen remains very low in spite of high concentrations of supplemental oxygen given to the patient. Systemic causes of lung injury include trauma, head injury, shock, sepsis, multiple blood transfusions, and medications. Pulmonary causes include pulmonary embolism, severe pneumonia, smoke inhalation, radiation, high altitude, near drowning, and more. Symptoms usually develop within 24 to 48 hours of the injury or illness. Cigarette smoking may be a risk factor. The incidence is 1 out of 100,000 people.