What radiographic and clinical features distinguish meconium aspiration syndrome (MAS) from other neonatal respiratory conditions, and how is MAS managed?

• A. MAS shows patchy infiltrates with areas of hyperinflation and coarse airways on radiographs; management includes oxygen therapy, airway clearance, supportive care; antibiotics if infection suspected; consider surfactant if severe.
• B. MAS shows uniform hazy edema on radiographs; treat with diuretics and fluid restriction only.
• C. MAS presents with pneumothorax; immediate chest tube placement.
• D. MAS presents with cardiomegaly and pleural effusion; management is surgical.

Answer: (A)

Meconium aspiration syndrome results when a newborn inhales meconium-stained amniotic fluid, causing both mechanical airway obstruction and chemical irritation of the lungs. This produces distinctive imaging and clinical patterns that help separate MAS from other neonatal respiratory conditions.

Radiographs typically show patchy, irregular or granular opacities scattered in the lungs with a tendency toward hyperinflation from air trapping. The airways may look coarse and inflamed, and there can be areas of atelectasis, often in the dependent parts of the lungs. This pattern—patchy infiltrates with hyperinflation in a term or near-term infant with meconium-stained fluid—is a classic clue for MAS.

Clinically, these infants are usually term or post-term and develop respiratory distress soon after birth. They may have grunting, retractions, tachypnea, cyanosis, and hypoxemia. The presence of meconium-stained amniotic fluid at delivery supports the diagnosis. MAS can range from mild to severe, and severe cases may be complicated by pulmonary hypertension or air leaks.

Management focuses on supporting oxygenation and clearing the airways. Provide oxygen to maintain adequate oxygen saturation, and use airway clearance strategies to help remove meconium and secretions. Many infants require noninvasive respiratory support like CPAP, and more severe cases may need careful intubation and mechanical ventilation with lung-protective settings. Surfactant therapy is considered if significant alveolar collapse or surfactant dysfunction is present. Antibiotics are added if infection is suspected. In some infants, persistent pulmonary hypertension may require targeted therapies such as inhaled nitric oxide. Monitor for and manage complications such as pneumothorax.