PDA Hemodynamic Significance Index (PDAsc) Calculator

PDA Severity Score (PDAsc) — Explanation and Clinical Context The PDA Severity Score (PDAsc) is a multivariable echocardiography-based prognostic index developed to quantify early hemodynamic significance of a patent ductus arteriosus in very preterm infants and predict the composite outcome of chronic lung disease or death before discharge. The score combines gestational age, echocardiographic PDA diameter (pulmonary end), left ventricular output (mL/kg/min), maximum velocity across the PDA (m/s), and lateral mitral annular tissue Doppler late diastolic velocity (a' in cm/s) into a single numeric index using the published formula above. A higher PDAsc indicates greater early shunt burden and physiological impact.

In the original derivation study the score ranged approximately 0–13; a cutoff of ≥5 identified infants at higher risk of CLD/death with high sensitivity and specificity, and the model had excellent discrimination (AUC ≈ 0.92). Use PDAsc as an adjunct to clinical assessment and serial echocardiography rather than an absolute trigger for treatment; local practice, gestational age, co-morbidities, and unit protocols should guide management decisions.