Objective: To assess efficacy of combined intratracheal pulmonary surfactant (PS) and inhaled nitric oxide (INO) on oleic acid induced acute respiratory distress syndrome (ARDS). Methods: Twenty NZW rabbits(2.4-3.2 kg) were anaesthetized, tracheotomized, intubated and mechanically ventilated. Oleic acid (75 μl/kg) was infused intravenously and induced ARDS within 6 h as reflected by 30% reduction of dynamic lung compliance(Cdyn), >50% reduction of PaO2/FiO2 (<200 mmHg), and increase of Qs/Qt >25%. Animals were treated in three groups by (1) mechanical ventilation (OA, n=8); (2) PS (100 mg/kg, n=7); and (3) PS (100 mg/kg) and INO(20 ppm, n=5, PSNO). PS was a porcine lung derived phospholipid extract containing >40% disaturated phosphatidylcholine. Blood gas values, oxygenation index (OI), Cdyn, airway resistance (Raw) and functional residue capacity (FRC, helium dilution) were measured. Results: Four animals in OA and 2 in PS group died of respiratory failure within 3 h of treatment. The values (mean±SD) at 4 h are shown as below:Table Conclusion: Combined PS and NO treatment mitigated deterioration of the lung function and intrapulmonary shunt due to oleic acid induced ARDS. (Supported by China Medical Board and Shanghai Education Foundation)

Table 1
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