Effect of pulmonary artery pressure on extravascular lung water in an experimental model of acute lung injury

Background: Lung edema can be influenced by hemodynamic changes in pulmonary circulation. The aim of this study was to evaluate, in an experimental model of acute lung injury, the effect on extravascular lung water (EVLW) of an increase in pulmonary artery pressure (Ppa) without changes in cardiac output and wedge pressure. Methods: Lung edema was produced by an intravenous oleic acid infusion in mixed‐breed pigs weighing 25–31 kg, which, after 20 min, were randomly assigned to a control group (100% FiO2) (n = 6) or a high Ppa group (21% FiO2) (n = 7). An increase in pulmonary artery pressure of at least 40% over baseline was produced in the high Ppa group by alveolar hypoxia. Hemodynamic, ventilatory and gas exchange parameters were collected at regular intervals. Pulmonary, wedge and capillary pressures were measured with a pulmonary artery catheter and the occlusion technique. EVLW was calculated gravimetrically. Results: At 240 min, both gravimetric‐measured EVLW and mean pulmonary artery pressures were significantly higher (P