High-frequency oscillatory ventilation of the perfluorocarbon-filled lung: Preliminary results in an animal model of acute lung injury

Objective: To examine the efficiency of gas exchange, hemodynamic function, and histopathologic evidence of lung protection using high- frequency oscillation of the perfluorocarbon-filled lung in a model of acute lung injury. Setting: An animal research laboratory. Design: A prospective, randomized animal study comparing animals randomized to high-frequency oscillation or high-frequency oscillation and perfluorocarbon administration (perfluoro-octyl bromide, perflubron, or LiquiVent). Subjects: Ten healthy swine (mean weight, 24.6 kg) with saline lavage-induced acute lung injury. Interventions: Animals were treated with repetitive saline lavage to achieve a uniform degree of acute lung injury (PaO₂ of <90 torr [11.9 kPa] on a FiO₂ of 1.0). After lung injury, subjects were changed to high-frequency oscillatory ventilation and stabilized for 1 hr. High-frequency oscillation of the perfluorocarbon-filled lung was initiated in five animals with the instillation of 30 mL/kg perflubron and five animals continued receiving high-frequency oscillation for a total duration of 2 hrs after the dosing period. Histopathologic evidence of lung injury was quantified by a pathologist using an eight-variable lung injury scoring system to generate a lung injury score. Measurements and Main Results: Administration of perflubron did not produce acute alterations of gas exchange. After the dosing period, there were no differences in gas exchange, hemodynamic function, or pulmonary vascular resistance between the two groups. The perfluorocarbon-treated animals had a significantly lower histopathologic total lung injury score, primarily manifested by significantly less atelectasis. Conclusions: The combination of high-frequency oscillatory ventilation and partial liquid ventilation with perflubron was well tolerated hemodynamically, was not associated with deterioration of gas exchange during dosing, and did not produce significant differences in either gas exchange or hemodynamic variables over a 2-hr period. There was histopathologic evidence that the combination of high-frequency oscillation and perflubron administration produces improved recruitment in both dependent and nondependent lung regions.