Please see page 106 of the pdf. Circulatory left to right shunts present an intruiging problem because O2 breathing will not substantially increase the O2 content of the unshunted blood or the total O2 delivery. In this study, pigs airways were blocked using steel beads. The pigs received infusions of DDFPe. Minutes after the infusion, the PaO2 increased in all treated animals. PaCO2 and pH normalized after infusion. The results lasted up to 5 hours. These results suggest that DDFPe infusion in combination with O2 breathing could be a valuable treatment to mitigate hypoxemia in right-to-left circulatory shunts of different etiologies.