Improved oxygenation by nitric oxide is enhanced by prior lung reaeration with surfactant, rather than positive end-expiratory pressure, in lung-lavaged rabbits

Objectives: The inhalation of nitric oxide increases oxygenation by improving the ventilation/perfusion ratios in neonates with respiratory distress syndrome and those ratios in adults with acute respiratory distress syndrome. There is evidence that inhaled nitric oxide is ineffective when the lung remains atelectatic and poorly inflated. This study aimed to enhance nitric oxide delivery by improving lung aeration by means of exogenous surfactant or by increasing positive end-expiratory pressure. Design: Experimental, comparative study. Setting: Research laboratory of a large university. Subjects: Twenty-eight adult New Zealand white rabbits, weighing 2.7 ± 0.3 kg. Interventions: Lung injury was induced by repeated whole-lung lavage with saline. The animals were mechanically ventilated with a tidal volume of 10 mL/kg, an Fio2 of 1.0, and a positive end-expiratory pressure of 6 cm H2O. Forty-five