The earliest signs are increased respiratory rate, dyspnoea, and cyanosis. On physical examination, a few fine inspiratory crackles may be audible. Chest x-ray shows diffuse bilateral pulmonary infiltrates, though these may initially be minimal or absent. Later the patient becomes more cyanosed and increasingly dyspnoeic and tachypnoeic.
Crackles become more prominent.
The chest x-ray may show complete opacification. Numerous complications may occur leading to multiorgan failure. Pulse oximetry Chest x-ray Monitoring of other parameters may be indicated according to the cause or to the occurrence of other organ failures.