High-frequency oscillatory ventilation with partial liquid ventilation in a model of acute respiratory failure.

Objective: To determine whether there is an improvement in oxygenation when partial liquid ventilation and high-frequency oscillatory ventilation are combined in the treatment of acute lung injury, compared with high-frequency oscillatory ventilation alone. Design: Controlled animal trial. Setting: Research laboratory in a university setting. Subjects: Ten 3-kg piglets. Interventions: Anesthetized piglets underwent high-frequency oscillatory ventilation, with mean airway pressure of 20 cm H 2 O, before induction of acute lung injury with repeated saline lavage. When Pao 2 values were <100 torr (<13.3 kPa), five animals were randomized to receive escalating doses (3, 15, and 30 mL/kg) of perflubron at 60-min intervals. The other five animals remained on high-frequency oscillatory ventilation only. Sham dosing was performed at 60-min intervals in these animals. Arterial blood gases were obtained in both groups at baseline, after injury, and after perflubron and sham doses. Measurements and Main Results: Statistically significant improvements in oxygenation were demonstrated in animals that received 3 mUkg of perflubron with high-frequency oscillatory ventilation compared with animals receiving high-frequency oscillatory ventilation alone (253 ± 161 vs. 90 ± 30 torr [33.65 ± 21.46 vs. 12.0 ± 4.0 kPa], p <.05). Improvements in oxygenation with additional administration of perflubron were not greater than the improvements seen in the high-frequency oscillatory ventilation-only group. Paco 2 and pH were similar in both groups at all times. No hemodynamic compromise occurred in either group of animals. Conclusions: The combination of low-dose perflubron with high-frequency oscillatory ventilation leads to more rapid improvement in arterial oxygenation than high-frequency oscillatory ventilation alone, in a piglet model of acute lung injury. Although the group receiving high-frequency oscillatory ventilation alone eventually achieved Pao 2 values that were equivalent to the group receiving high-frequency ventilation and perflubron, the combination of perflubron with high-frequency oscillatory ventilation may permit effective oxygenation and ventilation at lower mean airway pressures by facilitating alveolar expansion and decreasing intrapulmonary shunt.