Shunt and ventilation-perfusion distribution during partial liquid ventilation in healthy piglets

Mates, Elisabeth A., Jacob Hildebrandt, J. Craig Jackson,Peter Tarczy-Hornoch, and Michael P. Hlastala. Shunt and ventilation-perfusion distribution during partial liquid ventilation inhealthy piglets. J. Appl. Physiol.82(3): 933-942, 1997.Replacing gas in the lung withperfluorocarbon fluids (PFC) and periodically ventilating with a gas[partial liquid ventilation (PLV)] has been shown toimprove oxygenation in models of respiratory distress syndrome. Wehypothesized that the addition of PFC to healthy lungs would result inshunt, diffusion impairment, and increased ventilation-perfusion(A/) heterogeneity.Previously, Mates et al. showed thatO₂ shunt and arterial-alveolarCO₂ difference increased linearlywith dose in piglets given graded intratracheal doses of PFC (10, 20, and 30 ml/kg followed by mechanical ventilation with 100%O₂) (E. A. Mates, J. C. Jackson, J. Hildebrandt, W. E. Truog, T. A. Standaert, and M. P. Hlastala. In: Oxygen Transport to TissueXVI, 1994, p. 427-435). Here we reportA/ distribution inthe same animals, showing a 50% increase inA/ heterogeneity during PLV independent of PFC dose. Ventilation heterogeneity was themajor factor in this increase, and there was no significant change indead space ventilation. We also report on five animals given a single20 ml/kg dose of PFC and followed for 3 h. They showed an increase inshunt during PLV but no change in arterial-alveolar CO₂ difference.