NPPB and congenital diaphragmatic hernia: Postnatal assessment of disease severity in CDH infants is usually based on a combination of invasive and noninvasive markers, such as preferably preductal arterial blood gas analyses, oxygenation index (OI), laboratory markers like N-terminal-pro-B type natriuretic peptide (NT-proBNP), and echocardiography (23–25).