Reference no: EM132486917

A 57 year old man undergoes total knee replacement for severe degenerative joint disease. four days after surgery, he develops an acute onset of shortness off breath and right-sided pleuritic chest pain. He is now in moderate respiratory distress with a respiratory rate of 28 breaths per minute, heart rate of 120 bpm, blood pressure of 110/70 mm Hg. Oxygen saturation is 90%. on room air. Lung exam is normal and the cardiac exam reveals tachycardia. The right lower extremity has 2+ pitting edema, calf tenderness, erythema and warmth. The left leg is normal. You suspect a particular diagnosis.

With tha diagnosis in mind, which of the following is most likely in the above patient?

1. decrease pulmonary vascular resistance
2. increased alveolar dead space
3. normal alveolar0arterial PaO2 gradient
4. Increased surfactant production