Acute respiratory distress syndrome is an emergency medical condition characterized by acute respiratory failure that had a mortality rate over 50% since it has been described for the first time in 1967. Today, the annual incidence is between 1.5 and 79 new cases per 100,000 in the general population and postoperative incidence varies between 4,1 and 80% depending on the type of the surgery. The mortality rate for the mild ARDS is 27%, 32% for the moderate type and 45% for severe ARDS. The most common causes are: sepsis, pneumonia, and trauma, but there have been occurrences of ARDS as part of postoperative complications, more often cardial and toracal. The pathophysiology includes an increase in pulmonary permeability and the development of a pulmonary edema. Given that there is no single test or method to diagnose or exclude this diagnosis, there are large variations in incidence, and, subsequently, in treatment. The signs begin within the first week after an injury or an surgery as a progressive dyspnea, tachypnea, hypoxemia and cyanosis. Chest radiographic findings show diffuse alveolar damage. The ratio of arterial oxygen partial pressure to the fractional inspired oxygen determine the severity of the condition. The treatment is based on mechanical ventilation with lower flow rates and a positive end-expiration pressure, periodic repositioning into the prone position and treating the underlaying cause. Anesthetics, sedatives and neuromuscular blockers may also be used.