Natural surfactant combined with beclomethasone decreases oxidative lung injury in the preterm lamb

We performed a randomized study in preterm lambs to assess the hypothesis that the treatment with natural surfactant combined with beclomethasone might decrease pulmonary oxidative stress in an animal model of respiratory distress syndrome (RDS). Animals received 200 mg/kg of porcine natural surfactant or 200 mg/kg of natural surfactant combined with 400 or 800 microg/kg of beclomethasone. Lung tissue oxidation was studied by measuring total hydroperoxide (TH), advanced oxidation protein products (AOPP), and non-protein bound iron (NPBI) in bronchial aspirate samples. In addition, lung mechanics was evaluated. TH was lower in the groups treated with surfactant plus 400 or 800 microg/kg of beclomethasone than in the surfactant group; AOPP was lower in the group treated with surfactant plus 800 microg/kg of beclomethasone than in the other groups; NPBI was similar in all groups. Surfactant treatment was followed by a sustained improvement of tidal volume (TV) and airway resistance, while dynamic compliance did not vary. However, the mean airway pressure needed to obtain similar values of TV was lower in the group treated with surfactant plus 800 microg/kg of beclomethasone than in other groups. We concluded that natural surfactant combined with beclomethasone at 800 microg/kg is effective in reducing the oxidative lung stress and improving the respiratory function in an animal model of RDS.