MOST IMPORTANT TERMS- 1) Acute respiratory distress syndrome: This is a serious condition in which fluid builds up in the air sacs and lungs. As a result, oxygen cannot be transported and the level of oxygen in the blood decreases. 2) Air trapping (air trapping): In air trapping there is retention of air inside the lungs. Not all air is expelled during expiration and the lungs fill up. 3) Alpha1