Partial liquid ventilation (PLV) may offer enhanced lung protection in the management of acute lung injury. High frequency oscillatory ventilation (HFOV) has shown promise in infants with respiratory distress syndrome and children with acute lung injury. In the present study, we sought to define gas exchange during high frequency oscillation of the perfluorocarbon-filled lung (HFO-PLV) in an animal model of acute lung injury. METHODS: Ten healthy pigs(mean weight 25 kg) were anesthetized, instrumented, and ventilated supine with conventional mechanical ventilation (CMV) at standard settings followed by repetitive saline lavage until PaO2 was consistently ≤ 90 torr (FiO2 1.0) for one hour. Pigs were then converted to HFOV (f 7 Hz, MAP 12 cm H2O over MAP on CMV, ΔP titrated to PaCO2 45 - 55, FiO2 1.0). Five pigs then received 30 ml/kg of PFC over one hour (Liquivent®, perflubron, Alliance Pharmaceutical Corp.). HFO was continued at f 4 Hz for two hours. HFOV controls underwent sham dosing and analysis at similar intervals. Data were analyzed with two-way ANOVA with repeated measures. RESULTS: see table below. Data are presented as mean arterial O2 tension in torr (standard deviation). We found no significant differences in O2 or CO2 tension between groups at any time point. CONCLUSIONS: HFOV offers the possibility of enhanced lung protection while supporting gas exchange in the acutely injured lung. We demonstrated that the use of perflubron (30 ml/kg) does not lead to significant changes in oxygenation or ventilation in 20-30 kg swine following saline lavage. Further studies will define the ability of HFO-PLV to alter the progression of acute lung injury. This work was supported in part by Hoechst-Marion Roussel(Frankfurt, Germany).

Table 1