How is persistent pulmonary hypertension of the newborn (PPHN) diagnosed?

Updated: Sep 03, 2019
  • Author: Kate A Tauber, MD; Chief Editor: Howard S Weber, MD, FSCAI  more...
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Suspect PPHN whenever the level of hypoxemia is out of proportion to the level of pulmonary disease. Clinically, PPHN is most often recognized in term or near-term neonates, but it can occur in premature neonates. Preductal and postductal oxygen saturation measurements via pulse oximetry will often show a 10% or higher gradient difference, which is dependent on the magnitude of left-to-right shunting at the foramen ovale (with preductual saturations being higher). It is important to note that these findings are not specific to PPHN and must be differentiated from structural heart disease

In contrast to adult primary pulmonary hypertension, the newborn syndrome is not defined by a specific pressure of the pulmonary circulation. The diagnosis is confirmed regardless of the pulmonary arterial pressure, as long as it is accompanied by a right-to-left shunt and absence of congenital heart disease. [1]

Echocardiography is considered the most reliable noninvasive test to establish the diagnosis, assess cardiac function, and exclude associated structural heart disease.

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