What are the key clinical signs of Meconium Aspiration Syndrome in a newborn presenting with respiratory distress?

Key clinical signs of Meconium Aspiration Syndrome (MAS) in a newborn presenting with respiratory distress include:

• Respiratory distress manifesting as tachypnoea, grunting, nasal flaring, and chest retractions, indicating increased work of breathing ¹ (Reuter et al., 2014).
• Cyanosis due to impaired oxygenation from airway obstruction and inflammation caused by meconium in the airways ¹ (Dini et al., 2024).
• Coarse crackles and rhonchi on auscultation, reflecting airway obstruction and inflammation ¹ (Dini et al., 2024).
• Barrel-shaped chest or hyperinflation may be observed due to air trapping from partial airway obstruction ¹ (Reuter et al., 2014).
• Signs of hypoxia such as lethargy or poor feeding may be present secondary to respiratory compromise ¹ (Dini et al., 2024).
• In severe cases, signs of pulmonary hypertension and cardiovascular instability may develop, including hypotension and poor peripheral perfusion ¹ (Dini et al., 2024).

These clinical features arise from the pathophysiology of MAS, where aspirated meconium causes airway obstruction, chemical pneumonitis, surfactant dysfunction, and pulmonary vasoconstriction, leading to respiratory distress shortly after birth ¹ (Dini et al., 2024).