Timing of exogenous surfactant administration in a rabbit model of
acute lung injury.
Ito, Yushi, John Goffin, Ruud Veldhuizen, Mariamma Joseph, Dave
Bjarneson, Lynda McCaig, Li-Juan Yao, John Marcou, and Jim Lewis.
Lawson Research Institute, St. Joseph's Health Centre, Departments
of Physiology, Medicine, and Pathology, University of Western
Ontario, London, Ontario, Canada N6A 4V2
APStracts 2:0535A, 1995.
The purpose of this study was to evaluate early versus late
administration of exogenous surfactant in an adult rabbit model of
acute lung injury. Lung injury was induced by repetitive whole lung
saline lavage and subsequent mechanical ventilation. Bovine lipid
extract surfactant was instilled either 1 hr (EARLY) or 4 hr (LATE)
after the last lavage. Animals were monitored for 7 hr after the last
lavage. Although PaO2 values increased significantly immediately
after treatment in both the EARLY and LATE group, this improvement
was not sustained in the LATE group. There was also a higher
incidence of pneumothoraces in the LATE group versus both the EARLY
group and a non-treated control group. The ratio of poorly
functioning small surfactant aggregates to superior functioning large
aggregates was higher in the LATE group compared to the EARLY group.
Morphologic analysis revealed that early surfactant treatment
prevented the progression of lung injury over time. We conclude that
administration of exogenous surfactant at an early time point in lung
injury resulted in superior responses compared to later treatments.
Received 5 June 1995; accepted in final form 10 November 1995.
APS Manuscript Number A588-5.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 8 December 95