A 64-year-old woman is admitted to the hospital with right lobar pneumonia and sepsis syndrome. She becomes progressively shorter of breath and hypoxemic requiring intubation and mechanical ventilation. Her repeat CXR in the intensive care unit now shows diffuse pulmonary infiltrates and a diagnosis of acute respiratory distress syndrome (ARDS) is made. Which of the following mechanisms is the most likely cause for the early "exudative" phase of ARDS?
The increased vascular permeability is the hallmark of the disease. Diagnostic criteria include acute onset, PaO2 /FiO2 < 200 mm Hg (regardless of positive end-expiratory pressure level), bilateral infiltrate on frontal CXR, and pulmonary artery occlusion pressure < 18 mmHg (or if not measured, no evidence of left atrial hypertension).
increased lung compliance
increased interstitial fibrosis
increased vascular permeability to fluid and proteins
decreased pulmonary perfusion
Respiratory