2.4 | Surfactant depletion by lavage and LPS-induced
lung injury
After the baseline cardiopulmonary data had been collected, all rats
received lung lavage with 10 mL/kg normal saline intratracheally via a
tracheostomy tube for both sides of the lungs. An additional saline
lavage was given 5 min later if Spo2 remained above 90%. When
PaO2 dropped to less than 150 torr (20 kPa) (at
FiO2 = 1.0), the rat was considered to have reached
surfactant depletion. Subsequentially, a dose of 50 µg/kg LPS diluted by
saline to a total volume of 1 mL was intratracheally instilled into the
lungs to induce ALI. An additional 15 min period of postinjury
stabilization was allowed before the subsequent procedures.