Infants of 23 ( 0 ) to 27 ( 6 ) weeks ' gestational age requiring mechanical ventilation or 30 % supplemental oxygen on continuous positive airway pressure at 72-168 hours were randomized to receive 20 mg/kg ( 1 mL/kg ) nebulized pentoxifylline or an equal volume of normal saline placebo every 6 hours for 10 consecutive days via a vibrating mesh nebulizer .