Noninvasive Hemodynamics Assessment of Preterms With Successful Medical Closure of PDA

PDA in the first three days of life is a normal physiologic remnant in healthy term neonates. Conversely, a PDA in preterm neonates causes significant clinical sequelae as a result from left to right shunting. It is widely recognized that a hemodynamically significant PDA is known to contribute to increased morbidity and mortality. The increase in pulmonary blood flow in the setting of prematurity leads to pulmonary edema, noncompliant lungs, and worsening of respiratory status. Other sequelae of a hemodynamically significant PDA include intraventricular hemorrhage, necrotizing enterocolitis, congestive heart failure, and failure to thrive. Echocardiography is often used to evaluate hemodynamic significance of PDA. In general, pharmacological closure of PDA is less successful in infants with ductal diameter \>2mm. Lower ductal maximum velocity, which is usually associated with a larger PDA or higher pulmonary pressure, is another predictor of treatment failure . The use of echocardiography to gather meaningful hemodynamic data often necessitates serial assessments that can be tedious and labor-intensive. Electrical cardiometry (EC) is a non-invasive, impedance-based monitor that provides absolute cardiac output estimates in clinical practice. Unlike echocardiography, EC is simple to apply, continuous in measurements and not operator dependent.