Pulmonary inflammation plays an important role in the early development of CLD. Postnatal glucocorticoids have been shown effective in the prevention or treatment of CLD with various success. However, systemic glucocorticoid therapy often associated with various short term and long term complications. Therefore, modification of the therapeutic regimen is needed. Inhaled steroid, including inhaled budesonide,have been tried but the results are essentially unsuccessful, most likely due to small airways that the inhaled steroid reaching to the peripheral lungs are limited and unpredictable. Direct instillation of budesonide into the airway has also shown to be ineffective, possibly due to poor distribution of steroid in the lungs.

The investigators hypothesize that intratracheal instillation of budesonide, a strong tropical steroid, using surfactant as vehicle would facilitate the delivery of budesonide to the lung periphery and would inhibit lung inflammation and improve the pulmonary outcome. The result of our pilot study (Pediatrics, 2008) indicated this high possibility.

After informed consent is obtained, infant will be randomly assigned to two groups based on a double-blind design. Group I will receive surfactant and budesonide and GII will receive surfactant and air as control through endotracheal route. Therapy will be given every 8 hours until the infant require FIO2 < 30% or is extubated. The end point of assessment is the combined incidence of CLD and death judged at 36 weeks postconceptional age and the long term neurological and cognitive function at 2-3 years.

The incidence of CLD and death in the selective group of infant is about 60%. Using this 60% incidence in the placebo group and expected 40% (33% improvement) in the treated group, 130 infants in each group is needed to detected a difference, permitting a 5% chance of type I error and 10% chance of type II error. The total safe target number will be 300; 150 in each group. A collaborative study is therefore proposed. The primary outcome to be assessed is the combined incidence of CLD and death. The secondary outcome to be assessed is short term and long term side effects.

Inclusion Criteria:

• Infant with birth weight between 500-1500 gram
• Severe respiratory distress syndrome and requires mechanical ventilation with FIO2 > 60% shortly after birth

Exclusion Criteria:

• Severe congenital anomalities
• Lethal cardiopulmonary status at birth