DISTRIBUTION OF PULMONARY BLOOD-FLOW AND TOTAL LUNG WATER DURING PARTIAL LIQUID VENTILATION IN ACUTE LUNG INJURY

Background. Gas exchange is improved during partial liquid ventilation (PLV) with perfluorocarbon in animal models of acute lung injury. The mechanisms are not fully defined. We hypothesize that redistribution of pulmonary blood flow (PBF) along with redistribution of and decreas e in, total lung water (TLW) during PLV may improve oxygenation. Metho ds. We characterized PBF and TLW in anesthetized adult dogs by using p ositron emission tomography with (H2O)-O-15. Measurements of gas excha nge, PBF, and TLW were made before and after acute lung injury was ind uced with intravenous oleic acid The same measurements were made durin g PLV (with 30 ml/kg perfluorocarbon) and compared with gas ventilated (GV) controls. Results. Oxygenation was significantly improved during PLV. PBF redistributed from the dependent zone of the lung to the non dependent zones, thus potentially improving ventilation/perfusion rela tionships. However, a similar pattern of PBF redistribution was observ ed during GV such that there was no significant difference between gro ups. TLW redistributed in a similar pattern during PLV. By quantitativ e measurements, PLV ameliorated the continued accumulation of TLW comp ared with GV animals. Conclusions. We conclude that PBF and TLW redist ribution and attenuation of increases in TLW may contribute to the imp rovement in gas exchange during PLV in the setting of acute lung injur y.