Time-dependency of improvements in arterial oxygenation during partial liquid ventilation in experimental acute respiratory distress syndrome

Background:
The mechanisms by which partial liquid ventilation (PLV) can
improve gas exchange in acute lung injury are still unclear. Therefore, we
examined the time- and dose-dependency of the improvements in arterial oxygen
tension (PaO2) due to PLV in eight pigs with experimental lung
injury, in order to discriminate increases due to oxygen dissolved in
perfluorocarbon before its intrapulmonary instillation from a persistent
diffusion of the respiratory gas through the liquid column.

      Results:
      Application of four sequential doses of perfluorocarbon resulted
            in a dose-dependent increase in PaO2. Comparison of measurements 5
            and 30 min after instillation of each dose revealed a time-dependent decrease in
            PaO2 for doses that approximated the functional residual capacity of
            the animals.


      Conclusion:
      Although oxygen dissolved in perfluorocarbon at the onset of PLV
            can cause a short-term improvement in arterial oxygenation, diffusion of oxygen
            through the liquid may not be sufficient to maintain the initially observed
            increase in PaO2.