Several perfluorochemical (PFC) liquids with different and specific physical properties have been used as a means of improving pulmonary gas exchange and lung mechanics during respiratory distress. We evaluated APF-140M(Air Product and Chemicals, Inc.) with respect to gas exchange and lung mechanics in healthy and saline injured(SI) lungs of the juvenile New Zealand White rabbit. SI was created by repeated lung lavages (4-16 times, 10 cc/kg/lavage) with warm saline solution. PLV treated animals received intratracheal APF-140M at a volume equal to the measured pre-injury gas functional residual capacity (FRC = 18.6 ± 1.5 ml/kg). Seventeen rabbits, (age: 7-9 wks; wt. = 1.59 ± 0.1 kg SE) were assigned to three groups. Gr I (n=5) was treated with conventional mechanical ventilation (CMV) after establishing SI, Gr II (n=6) was treated with PLV after SI. Gr III (n=6) was supported with PLV without injury. All rabbits were supported with CMV gas ventilator strategy in which frequency was maintained constant and ventilatory pressures were adjusted to maintain constant tidal volume and minute ventilation. Sequential measurements of dynamic compliance(C) and arterial blood chemistry were performed in all groups (ie. after instrumentation, injury) and hourly for 4 hours thereafter. Oxygenation index (OI), and ventilation efficiency index(VEI) were calculated. Mean±SEM data at baseline(BI), Injury (Inj), 1 hour (1H), and 4 hours(4H) were:Table These data demonstrate: 1) following lung injury there was a significant (p<0.05) decrease in PaO2, C, VEI and increase in OI. 2) In Gr II, PLV significantly (p<0.05) improved PaO2 and OI. C was significantly (p<0.05) higher than Gr I at 1H. 3) there was a significant (p<0.05) decrease in C following PLV in Gr III. These results indicate that PLV with APF-140M caused a transient improvement in oxygenation and lung mechanics in the saline injured lung and sustained impairment of C in healthy lung of the juvenile rabbit model.(Supp in part by R29HD26341)

Table 1