636 Quantified Evaluation of the Ductus Arteriosus

Abstract

Introduction: We evaluated and quantified all ductal scans requested for predefined clinical signs and determined associations between clinical signs, ultrasound parameters and hemodynamic significance (HSDA) defined as ductal diameter (DAd) > 1.5 or >2.0 mm. Methods: Clinical signs were scored as mild (murmur, wide pulse pressure, hyperactive precordium), respiratory (difficulties to wean from or increase in respiratory support) or serious (hypotension, pulmonary edema or haemorrhage, congestive heart failure). Scans included central blood flow, DAd, ductal maximum velocity (Vmax), left pulmonary artery diastolic flow velocity (LPAd), LA/Ao ratio and flow pattern in the descending Aorta (DAo). Results: Eighty scans in 48 patients were analysed. Median (range) gestational age was 26 (23-31) weeks, postnatal age 7 (1-60) days. No associations were found between clinical signs and DAd > 1.5 or 2.0 mm. A murmur was best correlated with Vmax (Pearson 0.52, p 0.000). Hypotension and pulmonary haemorrhage were correlated with a larger ductal diameter (Pearson 0.34, p 0.002 and 0.40, p 0.000). A DAd > 1.5 mm was associated with higher LPAd, LA/Ao ratio and LVO (mean difference 15 cm/s; 95%CI 8 to 23, 0.24; 95%CI 0.12 to 0.36, 93 ml/kg/min; 95%CI 30 to 156 respectively). A DAd > 2.0 mm was associated with a lower Vmax (mean difference -95 cm/s; 95%CI -53 to -136) and more cases with reverse flow in the DAo (5% vs 55%). Conclusion: Clinical signs cannot predict ductal size. A DAd >1.5 is associated with known ultrasound parameters, a DAd >2.0 only with Vmax and DAo pattern.