The objective of this study was to determine if there is an improvement in oxygenation when partial liquid ventilation (PLV) and high-frequency oscillatory ventilation (HFOV) are combined in the treatment of acute lung injury, compared to HFOV alone. Ten anestetized 3-kg piglets underwent HFOV prior to induction of acute lung injury with repeated saline lavage. When PaO2 was less than 100 torr on 100% oxygen and mean airway pressure of 20 cm H2O, five animals were randomized to receive escalating doses (3 ml/kg, 15 ml/kg, 30 ml/kg) of perflubron (Liqui Vent R, Alliance Pharmaceutical Corp., San Diego, CA.) at 60 min. intervals. The other 5 animals were treated similarly except they did not receive perflubron. The PaO2 of the HFOV/PLV and HFOV groups were no different after lung injury (66±17 and 56±13, respectively). However, after 3 ml/kg perflubron in the HFOV/PLV group and sham dosing in the HFOV group (both receiving similar conventional breaths during dosing), the difference became significantly greater in the HFOV/PLV group compared to HFOV alone(253±161 torr vs. 90±30 torr, p<0.05). There was no difference between the groups after 15 ml/kg perflubron (313±130 torr vs. 259±161 torr) or after 30 ml/kg perflubron (328±80 torr vs. 331±164 torr). PaCO2 and pH were not different in either group at any time. No hemodynamic compromise occurred in either group. We conclude that the combination of PLV with HFOV leads to more rapid improvement in arterial oxygenation in a piglet model of acute lung injury, compared to HFOV alone, however, larger doses of perflubron were not more effective than continuation of HFOV alone. The combination of PLV with HFOV may permit effective oxygenation and ventilation at lower MAP's by facilitating alveolar expansion and decreasing intrapulmonary shunt.
