1. Acute bilateral pulmonary infiltrates
2. PaO2/FiO2<200
3. Worsening cardiac status due to hypoxia.
4. No cardiac cause of pulmonary congestion.

Answer: The answer is (c). The acute respiratory distress syndrome is a form of hypoxic respiratory failure caused by acute lung injury. There is disruption of the alveolar capillary membrane and therefore seepage of inflammatory cells and protein rich edema in the alveolar spaces. According to the American European Consensus Conference the definition of acute respiratory distress syndrome includes, acute bilateral pulmonary infiltrates, ration of PaO2 to FiO2 less than 200 and no underlying cardiac cause of volume overload. It does not require cardiac de-compensation for occurrence.