INTRODUCTION
Patent ductus arteriosus (PDA) is a common morbidity in extremely preterm infants. Failure of ductal closure has been associated with many severe morbidities, including broncopulmonary dysplasia (BPD), intraventricular hemorrhage (IVH), necrotizing enterocolitis (NEC) and mortality [1-4], but there is lack of evidence for a cause-and-effect relationship [5]. Practices in PDA management are not consistent among institutions ranging widely from universal prophylactic treatment to selective treatment on the basis of various clinical criteria, to no treatment at all [6].
The majority of extremely preterm infants receive invasive mechanical ventilation (IMV) to maintain oxygenation and ventilation [7] and prolonged IMV has been associated with an increased risk of mortality and neonatal morbidities, including upper airway injury, nosocomial infections and BPD [8-10]. Failed extubation is also independently associated with increased risk of mortality, BPD, severe IVH, longer hospitalization, more days on respiratory support and significant respiratory setback lasting multiple days after re-intubation.[11-15]
There have been reports of an association between presence of PDA and extubation failure in preterm infants [16, 17]. Limitations of these studies include small sample size (9 out of 39 infants [16] and 22 out of 82 infants [17]) with extubation failure, lack of use of Nasal Intermittent Positive Pressure Ventilation (NIPPV) prior to re-intubation [17] and lack of data on the timing of diagnosis of PDA.
The objective of the current study was to evaluate the association between a hemodynamically significant PDA and failure of first elective extubation among extremely low birth weight infants.