Patent ductus arteriosus (PDA) staging and splanchnic circulation in high risk preterm infants

Patent ductus arteriosus (PDA) is a common complication in preterm infants, especially in extremely low birth weight (ELBW) infants with an incidence of 80-90%.1 The current body of evidence showed a significant association between PDA and neonatal mortality and morbidities, mainly due the presence of left to right shunt -ductal steal phenomenaand consequent hypoperfusion to vital organs.2,3 However, there is a growing controversy about the role of aggressive therapeutic interventions in the management of PDA, previous reports indicated that 73% of preterm infants with PDA will show spontaneous closure of the duct by the end of first week and that the beneficial role of medical/surgical treatment is questionable.4,5 Thus, it is important to identify and discriminate infants with hemodynamically significant ductus arteriosus (hsPDA). A growing body of evidence has investigated the role of several methods in the identification of hsPDA. Biomarkers, as natriuretic peptides and ischemia-modified albumin, were reported to significantly correlated with early hsPDA and have a good predictive value.6,7 Other reports showed high diagnostic accuracy of clinical scores for the detection of hsPDA infants who needs treatment.8 However, there is no consensus about a grading system for hsPDA; functional echocardiography is considered as gold standard in the early diagnosis of significant PDA and focus on early targeted treatment.9 McNamara & Sehgal,10 proposed a staging system with a comparison between clinical and echocardiographic criteria of hsPDA.