title: Timing of exogenous surfactant administration in a rabbit model of acute lung injury.
abstract: The purpose of this study was to evaluate early vs. 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 (Early) or 4 h (Late) after the last lavage. Animals were monitored for 7 h after the last lavage. Although arterial PO2 values increased significantly immediately after treatment in both the Early and Late groups, this improvement was not sustained in the Late group. There was also a higher incidence of pneumothoraxes in the Late group vs. both the Early group and a nontreated control group. The ratio of poorly functioning small surfactant aggregates to superior functioning large aggregates was higher in the Late group compared with the Early group. Morphological 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 with later treatments.
authors.affiliation: Lawson Research Institute, St. Joseph's Health Centre, Department of Physiology, University of Western Ontario, London, Canada.
authors.forename: Y
authors.initials: Y
authors.lastname: Ito
authors.forename: J
authors.initials: J
authors.lastname: Goffin
authors.forename: R
authors.initials: R
authors.lastname: Veldhuizen
authors.forename: M
authors.initials: M
authors.lastname: Joseph
authors.forename: D
authors.initials: D
authors.lastname: Bjarneson
authors.forename: L
authors.initials: L
authors.lastname: McCaig
authors.forename: L J
authors.initials: LJ
authors.lastname: Yao
authors.forename: J
authors.initials: J
authors.lastname: Marcou
authors.forename: J
authors.initials: J
authors.lastname: Lewis
mesh_terms: D000818:Animals; D002417:Cattle; D004195:Disease Models, Animal; D008168:Lung / Q000648:ultrastructure; D011659:Pulmonary Gas Exchange; D011817:Rabbits; D012128:Respiratory Distress Syndrome / Q000188:drug therapy*; D012129:Respiratory Function Tests; D013501:Surface-Active Agents / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D013501:Surface-Active Agents