Surfactant tracheobronchial lavage for the management of a rabbit model of meconium aspiration syndrome.
We evaluated the effect of tracheobronchial lavage with diluted surfactant solution (bovine lipid extract surfactant, bLES) in a rabbit model of meconium aspiration. All animals were anaesthetized, tracheotomized and given 3-4 ml/kg of 25% slurry of human meconium into the endotracheal tube and mechanically ventilated for 1 h. The animals were then randomly assigned to surfactant lavage (n = 12) with 15 ml/kg of diluted surfactant at a concentration of 5.4 mg phospholipid/ml administered in aliquots of 2 ml; or simple endotracheal suction (control n = 12) when the oxygenation index (OI) was >/=15. Changes in the arterial blood gases and the histomorphological 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 improvements were observed throughout the ensuing 4 h of ventilation. There was significantly more solid content recovered by surfactant lavage compared with the 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 treatment groups, as much improved in 5 and improved in 4, whereas the control rabbits were rated as much worse in 3 and worse in 4. Histological examination showed the lungs of the lavaged rabbits had significantly more normal airway (p < 0.0001), more fields showing completely normal airspace (p = 0.0001) and less fields showing severe overdistension with meconium (p = 0.0005). We concluded that lavage with diluted surfactant solution effectively washed out the meconium, improved gases exchanges, and improved the histological and radiological appearances in the rabbit model of MAS.
Lam
B C
BC
Department of Paediatrics, University of Hong Kong, Hong Kong, China. lamccb@ha.org.hk
Yeung
C Y
CY
Fu
K H
KH
Wong
K Y
KY
Chan
F L
FL
Tsoi
N S
NS
D000818:Animals; D018893:Bronchoalveolar Lavage; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008168:Lung / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008471:Meconium Aspiration Syndrome / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000473:pathology; D011247:Pregnancy; D011659:Pulmonary Gas Exchange; D011663:Pulmonary Surfactants / Q000008:administration & dosage* / Q000627:therapeutic use; D011817:Rabbits; D011859:Radiography; D012121:Respiration, Artificial; D012996:Solutions; D013396:Suction; D014132:Trachea
D011663:Pulmonary Surfactants; D012996:Solutions