Infants with meconium aspiration syndrome (MAS) should be monitored closely for the development of which condition?

• A. Pulmonary hemorrhage
• B. PIE
• C. Pneumonia
• D. Persistent pulmonary hypertension of the newborn (PPHN)

Answer: (D)

Meconium aspiration can cause chemical injury to the lungs and trigger intense pulmonary vasoconstriction, leading to persistently high pulmonary vascular resistance after birth. This persistent resistance promotes right-to-left shunting at the foramen ovale and/or ductus arteriosus, which is the hallmark of persistent pulmonary hypertension of the newborn. Because MAS sets the stage for PPHN, infants need vigilant monitoring of oxygenation and ventilation, with attention to hypoexemia that remains despite adequate respiratory support. Echocardiography may be used to assess pulmonary pressures and shunting, guiding therapies such as strategies to lower pulmonary vascular resistance (for example, inhaled nitric oxide) and advanced support if needed. While MAS can be associated with other pulmonary complications like pneumonia or hemorrhage, PPHN is the key condition to watch for due to its impact on oxygenation and its demand for targeted management.