INTRODUCTION
Preterms may account for only 6-12% of all newborns but are the majority of NICU admissions. PDA is a frequent co-morbidity in the NICU preterm baby. Its incidence is inversely proportional to the gestational age.
32 weekers 20% have PDA
26 weeker or less 80-90% have PDA
Spontaneous closure of PDA also depends on the gestational age. In 28 weeker, for example, about 73% of babies had a spontaneously closed PDA by the end of the first week.
PDA is associated with not only increased mortality but also increased morbidity including heart failure, respiratory support, supplemental oxygen, BPD, pulmonary hemorrhage, IVH, abnormal cerebral perfusion, and necrotizing enterocolitis. But the closure of PDA (by pharmacological or surgical means) has not been associated with a decreased morbidity of the conditions mentioned.
So, in keeping with this, the indication to close PDA has decreased for those who are extremely low birth weight and those on respiratory support or those at high risk of rapidly developing hsPDA.
BASICS OF ECHO FOR PDA
Although the focus of a functional echo is Ductus, an echo has to be able to rule out CHD. Some CHD may be duct-dependent. Functional Echo should check
Structural Heart Issues
Biventricular Function
Transitional Circulation issues
DUCTAL PATENCY
Views in which Ductal Patency can be seen”
Parasternal Short Axis
Suprasternal Ductal View
Parasternal Long Axis in PA tilt
Apical 4 chamber does not show the Ductus
DUCTAL SIZE
Ductal View ie High Parasternal Short Axis view shows Ductus clearly and the idea is to measure the narrowest segment of the PDA.
Measurement of the PDA is NOT very accurate. It can only be measured in 2D or Color. Though color is not recommended because it may result in an exaggerated size measurement.
Less than 1.5 mm is considered small
1.5 to 3 mm is moderate and
More than 3 is large
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