Asthma USMLE Step 1 Practice Question
A male infant is born at 32 weeks gestation to a mother with poorly controlled diabetes. Within minutes of birth he develops tachypnea, grunting, nasal flaring, and intercostal retractions. Chest radiograph shows diffuse reticulogranular ground glass opacities with air bronchograms. Which of the following is the most likely primary mechanism of this infant's disease?
Answer choices
- ADecreased surfactant causing increased alveolar surface tension and collapseCorrect answer
- BFailure of alveolar macrophage activation leading to impaired bacterial clearance
- CDestruction of elastic tissue by neutrophil elastase
- DPersistence of fetal pulmonary vascular resistance causing right to left shunting
- EAbnormal foregut partitioning causing aspiration of feeds
- FIncreased pulmonary capillary permeability leading to interstitial and alveolar edema
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