PURPOSE:The aim of this study was to assess the effect of partial liquid ventilation (PLV) and conventional mechanical ventilation (CMV) in the pattern of distribution of lung injury in a rabbit model of acute lung injury. MATERIALS AND METHODS:Animals (1.5 to 3.5 kg) were assigned to receive CMV (tidal volume of 10 mL/kg and a PEEP of 5 cm H2O) or PLV with 18 mL/kg of intratracheal perflubron (tidal volume of 10 mL/kg and a PEEP of 5 cm H2O). Lung injury was elicited by intravenous administration of Escherichia coliendotoxin. Uninjured animals ventilated as the CMV group served as controls. After 4 hours of mechanical ventilation, the lungs were removed and tissue injury was assessed by light microscopy using a scoring system. RESULTS:Animals in the CMV group had higher lung injury scores in comparison to the PLV group (10+/-4.5 vs. 5+/-3.3, respectively, P < .05). The injury scores were similar for nondependent lung regions (CMV: 8+/-4.3, PLV: 6+/-2.9) but significantly different for the dependent regions (CMV: 12+/-4.6, PLV: 5+/-3.8, P< .05). CONCLUSIONS:PLV is associated with significant attenuation of lung injury, in comparison to CMV. This effect is predominantly due to attenuation of injury in the dependent region of the lung.