Comparison of Two PDA Severity Scores

Several echocardiographic scoring systems have been developed to assess severity of PDA shunting in preterm infants. We compared the ability of two different scoring systems to evaluate hemodynamic significance of the PDA and their correlation with long term morbidities.

EL-Khuffash et al [1] reported a day 2 PDA severity score that was predictive of a combined outcome of chronic lung disease or death before discharge. The Shaare Zedek Medical Center has been using a different four parameter score to evaluate preterm neonatal PDAs. In an attempt to assess the ability of the SZMC score to similarly predict outcome, we applied the SZMC scoring method to the cohort previously used to evaluate the El Khuffash scoring system. The El Khuffash cohort included 141 infants with mean gestational age of 26 + 1.4 weeks and mean birth weight of 952 + 235 grams.

The SZMC PDA severity score consists of four commonly used PDA related echocardiographic parameters including ductus arteriosus diameter, left-atrial:aorta ratio, retrograde diastolic flow in the abdominal aorta and ductus arteriosus shunt flow pattern. Each of these parameters was graded from 0-2 yielding a composite score ranging from 0 (closed ductus) to 8. A composite score of > 6 was defined as hemodynamically significant; score of 3-5 as borderline significance; score of 0-2 as hemodynamically insignificant PDA.

The scores were found to be well-correlated with one another (Figure 1.) Although both scores would have predicted CLD/Death in this population, certain differences were observed in the correlations with other potentially PDA associated morbidities. Whereas the El-Khuffash score correlated significantly with NEC, the SZMC score did not. The SZMC score, on the other hand, correlated significantly with PVL (Table 1.)

References

1. El-Khuffash A, et.al. A Patent Ductus Arteriosus Severity Score Predicts Chronic Lung Disease or Death before Discharge. J Pediatr. 2015;167:1354-1361