Vaporized perfluorocarbon improves oxygenation and pulmonary function in an ovine model of acute respiratory distress syndrome

Background: Perfluorocarbon liquids are being used experimentally and in cl inical trials for the treatment of acute lung injury. Their resemblance to inhaled anesthetic agents suggests the possibility of application by vapori zation. The authors' aim was to develop the technical means for perfluoroca rbon vaporization and to investigate its effects on gas exchange and lung f unction in an ovine model of oleic acid-induced lung injury. Methods: Two vaporizers were calibrated for perfluorohexane and connected s equentially in the inspiratory limb of a conventional anesthetic machine. T wenty sheep were ventilated in a volume controlled mode at an inspired oxyg en fraction of 1.0. Lung injury was induced by intravenous injection of 0.1 mi oleic acid per kilogram body weight. Ten sheep were treated with vapori zed perfluorohexane for 30 min and followed for 2 h; 10 sheep served as con trols. Measurements of blood gases and respiratory and hemodynamic paramete rs were obtained at regular intervals. Results: Vaporization of perfluorohexane significantly increased arterial o xygen tension 30 min after the end of treatment (P < 0.01). At 2 h after tr eatment the oxygen tension was 376 +/- 182 mmHg (mean +/- SD). Peak inspira tory pressures (P < 0.01) and compliance (P < 0.01) were significantly redu ced from the end of the treatment interval onward. Conclusion: Vaporization is a new application technique for perfluorocarbon that significantly improved oxygenation and pulmonary function in oleic ac id-induced lung injury.