Partial liquid ventilation influences pulmonary histopathology in an animal model of acute lung injury

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 coli endotoxin. 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. Copyright (C) 1999 by W.B. Saunders Company.