According to the literature, pulmonary entities that would eventually cause raised NT-proBNP levels due to the underlying cardiac stress include the persistent pulmonary hypertension of the newborn (PPHN) and Acute Respiratory Distress Syndrome (ARDS), and several studies have associated the high NT-proBNP levels with ventilator weaning and extubation failure [24]. This evidence concerns the gene NPPB and persistent fetal circulation syndrome.