[An index internal diameter ductus arteriosus/body surface area as a need for closure of duct in the preterm newborn]

To determine a rate of internal diameter (ID), the narrowest of ductus arteriosus (DA)/body surface area (BSA) in preterm newborns (PTNB) for need for closure of DA either medically or surgically.

Prospective (cohort), held in a Neonatology Service in February 2010 to January 2011. Inclusion criteria were PTNB from 28 to 36 weeks of gestation from 0 to 28 days after birth, which confirmed diagnosis of patent ductus arteriosus (PDA) by echocardiogram, taking the narrowest ID, who did not present heart complex congenital or other major malformations in other systems without pulmonary arterial hypertension, that had not received drug treatment with prostaglandin inhibitors to close the DA. The exclusion criteria for complications of mechanical ventilation (air leaks, atelectasis, etc.) before measurements. BSA was determined based on their weight and height. There were two comparison groups during its evolution, those who finally merited either closure medical or surgical closure or was indicated but the poor conditions of the patient by the same PDA mainly, the procedure was not carried out (Group A) and Group B, those that are not operated or not medically closed DA not being hemodynamically significant [corrected]. Statistical analysis was performed using descriptive statistics and inferential. Significance levels were set at p < 0.05.

The study population consisted of 32 patients who were divided into two groups: group A of 13 patients and group B with 19 patients. The study population characteristics between the two groups showed significant difference only in the Apgar Score for the Group B. In multivariate analysis found statistically significant as need for closure of DA only a index ID DA/ BSA when it was > 14.

It is important to take into account a number of known ways to assess whether the DA is hemodynamically significant and therefore should be closed medically or surgically and according to this study, a parameter to requiring its closure is an index ID DA/BSA with a value > 14.