OXYGENATION, PULMONARY MECHANICS AND LUNG INJURY IN SURFACTANT DEFICIENT RABBITS RECEIVING CONVENTIONAL MECHANICAL VENTILATION (CMV) WITH OR WITHOUT PERFLUOROCARBON-ASSOCIATED GAS EXCHANGE (PAGE)

Abstract 104

Objectives: To investigate the effect on oxygenation, pulmonary mechanics and lung injury of CMV with PAGE versus CMV alone in a surfactant deficient lung disease model in rabbits.

Methods: Surfactant-deficient lung injury was induced with saline lavage in 12 ventilated rabbits which were then assigned to continue CMV (n = 6) or CMV+PAGE (n = 6). The CMV+PAGE group had 30 mls/kg of perfluorocarbon liquid (FC-77, 3M Pharmaceuticals) instilled into the endotracheal tube over 20 minutes, with subsequent regular top-ups. Arterial blood gases were taken pre-lavage, post-lavage (time = 0) and then hourly(hours 1 to 5). Lung compliance (COMP) and resistance (RES) were measured pre-lavage and at hours 0, 1 and 5. At 5 hours the rabbits were killed(barbiturate overdose) and the lungs removed for histology.

Results: There were no significant differences between groups in weight, number of lavages, oxygenation, COMP and RES pre and post-lavage. Figures show mean (SD). Table

Table 1

Conclusions: There is an immediate improvement in OI and a sustained improvement in PaO₂ over the first three hours with PAGE, and a trend toward improvement in pulmonary mechanics. There were no differences in lung injury score.