What is the key difference in the pathophysiology between Transient Tachypnea of the Newborn (TTN) and Respiratory Distress Syndrome (RDS)?

The key difference in the pathophysiology between Transient Tachypnea of the Newborn (TTN) and Respiratory Distress Syndrome (RDS) lies in the mechanisms that lead to respiratory distress.

In TTN, the underlying issue is inadequate fluid clearance from the lungs. This condition is often seen in infants who are born via cesarean section without preceding labor, as the thoracic squeeze that occurs during vaginal delivery can help clear fluid from the lungs. The retained fluid leads to mild respiratory distress, typically presenting shortly after birth and resolving within a few days.

On the other hand, RDS, also known as hyaline membrane disease, arises primarily due to surfactant deficiency. Surfactant is a substance that reduces surface tension within the alveoli, preventing their collapse and aiding in lung expansion during breathing. In preterm infants, the lungs may not produce enough surfactant, resulting in atelectasis (alveolar collapse) and significant respiratory distress.

Thus, the correct answer highlights that TTN is primarily due to inadequate fluid clearance while RDS is specifically caused by surfactant deficiency, underscoring the different pathophysiological mechanisms involved in these two conditions.