PARTIAL LIQUID BREATHING WITH PERFLUBRON IMPROVES ARTERIAL OXYGENATION IN ACUTE CANINE LUNG INJURY

Tidal liquid breathing with perfluorocarbon liquid improves lung mecha nics and gas exchange in surfactant-deficient lambs. We asked whether an intratracheal dose of perflubron equal to liquid functional residua l capacity (FRC) or less (partial liquid breathing) would alter gas ex change in gas-ventilated, anesthetized, and oleic acid (OA)-injured do gs. We gave eight dogs perflubron in six aliquots, each equal to one-s ixth of liquid FRC [sequential dose (SEQ) group], starting 90 min afte r OA. Two other groups of eight dogs each received a liquid FRC dose o f perflubron (60-70 ml/kg) either just before (P-Pre) or 90 min after (P-Post) OA, and eight control (CON) dogs received OA but no perflubro n. In CON, SEQ, and P-Post dogs, OA caused a significant decrease in s tatic respiratory system compliance (Crs) (1.50 +/- 0.05 to 1.15 +/- 0 .06 ml.cmH(2)O(-1).kg(-l)) and arterial Po, (508 +/- 10 to 113 +/- 16 Torr) by minute 90. In P-Pre, P-Post, and after the third dose of perf lubron (50% FRC) in SEQ dogs, arterial Po-2 was significantly higher t han that in the CON dogs but was similar to that in the CON dogs after perflubron removal. Perflubron doses less than two-thirds of liquid F RC were associated with increased Crs compared with CON dogs, but furt her lung filling caused a decrease in Crs. Lung histology showed wides pread edema and hemorrhage and was similar in perflubron and CON dogs. O-2 delivery and uptake were well maintained in all four groups. Thes e data show that conventional gas ventilation combined with a dose of perflubron equal to or less than liquid FRC can improve oxygenation wi thout hemodynamic compromise in acute lung injury.