Persistent ductus arteriosus (DA) is a common entity in the premature newborn and is associated with high morbidity and mortality. There is still controversy about which is the best treatment for its closure. Children with AD who receive pharmacological treatment present more frequently than other premature children, necrotizing enterocolitis or isolated intestinal perforation.

At the present time, the conventional treatment of DA consists in the administration of intravenous ibuprofen, slow bolus in 3 daily doses 10-5-5 mg / kg / day. Recently, it has been observed that treatment with ibuprofen in continuous iv infusion for 3 days seems to be more effective in closing DA than conventional treatment for 3 days with the same dose but in slow iv bolus. This experimental treatment reduced the incidence of associated necrotizing enterocolitis. Our group demonstrated in a previous pilot trial that the guided treatment with echocardiography (EchoG) of DA with ibuprofen compared with conventional treatment, allows to reduce the number of doses to the patient. The EchoG treatment thus presents a potential reduction of side effects associated with medication, this resulted in a tendency to have a lower incidence of necrotising enterocolitis in the experimental group. This multicenter clinical trial aims to test the hypothesis that the combination of 2 experimental treatments, the use of ibuprofen in continuous perfusion and EchoG, reduces the incidence of digestive side effects (necrotising enterocolitis or isolated intestinal perforation) compared to the treatment also guided by echocardiography but slow bolus iv.

Inclusion Criteria:

• Preterm infants with less 33 weeks of gestational age
• DA ≥ 1.5 mm with decision to start pharmacological treatment
• Informed consent signed by the legal representative

Exclusion Criteria:

• Consent denied
• Presence of serious congenital alterations
• Congenital heart disease
• Contraindication for the administration of IB: oligoanuria (diuresis <1cc / kg / h), bleeding severe recent intraventricular (HIV grade III or extensive periventricular hemorrhagic infarction), serum creatinine> 1.5 mg / dl or clinical suspicion of intestinal ischemia.

A randomized system with closed envelopes will be designed in which patients will be assigned to one of the 2 treatment groups, stratified by gestational age (<28 weeks and ≥28 weeks) and by hospital center. In each center and each stratum, they will be randomly assigned in a 1: 1 ratio to each group of study. The assignment will be sequential.

The doctors responsible for the patient will be blind to the intervention but will be responsible for the sealed envelopes, and at the time of patient randomization, will deliver the sealed envelope corresponding to the nurses responsible for the preparation of the medication.