A patient has undergone an operation on account of perforated ulcer of stomach, terminal phase of diffuse peritonitis and endotoxic shock. In the postoperative period he is prescribed artificial pulmonary ventilation with 60% oxygen inhalation. Blood gases: Pa02- 7078 mm Hg, hypoxemy doesn't ecrease, CVP (central venous pressure) - 150180 mm of water column, AP- 90/60 mm Hg (against the backgound of taking big doses of dopamine). Radiogram shows diffuse pulmonary infiltration. What cause the refractory arterial hypoxemia?