Meconium Aspiration Syndrome

  • Etiology: post-term neonate who passes meconium in utero due to fetal distress, fetal distress leads to fetal gasping and aspiration of amniotic fluid containing meconium, causes chemical pneumonitis and airway obstruction
  • CXR: increased lung volumes (hyperinflation) and coarse interstitial infiltrates
  • Complications: airleak (pneumothorax / pneumomediastinum) from airway obstruction, persistent fetal circulation / persistent pulmonary hypertension due to no decrease in peripheral vascular resistance
  • Clinical: diagnosis made during intubation when meconium is noted beneath vocal cords, persistent pulmonary hypertension can be primary in nature – baby fails to convert to adult circulation, but meconium aspiration syndrome can be a cause of persistent pulmonary hypertension: meconium aspiration syndrome -> hypoxia -> persistent pulmonary hypertension

Cases of Meconium Aspiration Syndrome

CXR of meconium aspiration syndrome
Initial CXR shows increased lung volumes and coarse interstitial infiltrates.
CXR of a highly positioned endotracheal tube in a patient with meconium aspiration syndrome
CXR AP shows the tip of the endotracheal tube to be above the thoracic inlet. The lungs are hyperinflated and there are coarse interstitial infiltrates bilaterally.