Why is exogenous surfactant often indicated in severe MAS?

• A. Because meconium decreases endogenous surfactant synthesis and activity
• B. Because antibiotics are ineffective against meconium-related injury
• C. Because steroids are contraindicated in MAS
• D. Because oxygen therapy alone is sufficient

Answer: (A)

In MAS, meconium in the airways damages the lung surface by inactivating endogenous surfactant and hindering its production. This raises surface tension, causes alveolar collapse, lowers lung compliance, and leads to severe hypoxemia. Replacing the damaged surfactant with an exogenous surfactant directly lowers surface tension, reopens collapsed alveoli, improves compliance, and enhances oxygenation. That direct mechanism is why surfactant replacement is indicated in severe MAS. Antibiotics, steroids, or relying on oxygen alone don’t address the underlying surfactant dysfunction in MAS.