A prospective , randomized , double-dummy study was conducted on 112 very low birth weight infants ( mean gestational age 27.2 weeks , SD 2 ; birth weight 1,019 g , SD 330 ) with HsPDA , 56 of whom were given IBU in conventional 15-min intermittent boluses , while the other 56 were administered IBU as a 24-hour continuous infusion , both at standard doses ( 10/5/5 mg/kg ) .