Which respiratory disorder is most commonly associated with an overinflated chest appearance on exam?

• A. Meconium aspiration syndrome (MAS)
• B. Respiratory Distress Syndrome (RDS)
• C. Transient Tachypnea of the Newborn (TTN)
• D. Bronchopulmonary dysplasia

Answer: (A)

Hyperinflation on examination is most characteristic ofTransient Tachypnea of the Newborn. TTN occurs when fetal lung fluid clearance is delayed, leading to air trapping and an overexpanded chest. This results in rapid breathing with mild to moderate retractions and a visibly hyperinflated thorax. While meconium aspiration can cause respiratory distress and may occasionally show air trapping, the hallmark exam finding of a visibly overinflated chest most strongly points to TTN rather than RDS (which tends to show underinflation and atelectasis), bronchopulmonary dysplasia (a chronic, long-term change), or MAS (which varies and is not defined by hyperinflation).