Surfactant tracheobronchial lavage for the management of a rabbit model ofmeconium aspiration syndrome

We evaluated the effect of tracheobronchial lavage with diluted surfactant solution (bovine lipid extract surfactant, bLES) in a rabbit model of mecon ium aspiration. All animals were anaesthetized, tracheotomized and given 3- 4 ml/kg of 25% slurry of human meconium into the endotracheal tube and mech anically ventilated for 1 h. The animals were then randomly assigned to sur factant lavage (n = 12) with 15 ml/kg of diluted surfactant at a concentrat ion of 5.4 mg phospholipid/ml administered in aliquots of 2 ml; or simple e ndotracheal suction (control n = 12) when the oxygenation index (OI) was gr eater than or equal to 15. Changes in the arterial blood gases and the hist omorphological and radiological appearances of the lungs were recorded. The OI and arterial/alveolar oxygen tension (a/A PO2) of the surfactant lavage group improved significantly at 5 min post-treatment, and these improvemen ts were observed throughout the ensuing 4 h of ventilation. There was signi ficantly more solid content recovered by surfactant lavage compared with th e control group (p = 0.0001). Radiologically, the post-treatment air space opacification scores of the lavage group were significantly lower compared with the control (p = 0.002). The post-treatment radiographs of the lavage- treated rabbits were rated by the radiologist, who was blinded to the treat ment groups, as much improved in 5 and improved in 4, whereas the control r abbits were rated as much worse in 3 and worse in 4. Histological examinati on showed the lungs of the lavaged rabbits had significantly more normal ai rway (p < 0.0001), more fields showing completely normal airspace (p = 0.00 01) and less fields showing severe overdistension with meconium (p = 0.0005 ). We concluded that lavage with diluted surfactant solution effectively wa shed out the meconium, improved gases exchanges, and improved the histologi cal and radiological appearances in the rabbit model of MAS. Copyright (C) 2000 S. Karger AG, Basel.