Meconium Aspiration Syndrome

Question 1

Definition

Answer 1

o Meconium-stained amniotic fluid (MSAF) occurs in about 15 % of deliveries
o Not all neonates with MSAF develop meconium aspiration syndrome (MSA)
o MAS occurs only in 5 % of infants with MSAF

Question 2

Factors that promote the passage of meconium in utero include the following:

Answer 2

Perinatal asphyxia
o Oligohydramnios
o Maternal infection/chorioamnionitis
Stress

Question 3

Pathophysiology

Answer 3

Meconium may be aspirated before, during, or just after birth

3. Outcome of meconium aspiration:
   - Complete airways obstructionp ➡️Patchy collapse
   - Incomplete airways obstruction ➡️ Air trapping.
   - Secondary infection & chemical pneumonitis➡️ Surfactant dysfunction
   - Pulmonary hypertension

Question 4

Clinical picture

Answer 4

o MAS occur typically in term and post-term infants
o Skin, nails and umbilical cord may be meconium stained
o Signs of severe respiratory distress with grunting and cyanosis
o Barrel chest in the presence of air trapping
o Auscultated rales and rhonchi (in some cases)
o May have signs of neonatal encephalopathy

Question 5

Chest radiograph

Answer 5

y Hyperinflated chest with patchy consolidations and collapse (A)
y May be air leak e.g. pneumothorax (B) , pneumopericardium (C)

Question 6

Treatment of meconium aspiration includes

Answer 6

*Prevention: by tracheal suction before stimulation of breathing.

*general supportive care by Oxygen, fluid, correct acidosis
*Assisted ventilation by CPAP or mechanical ventilation.
Poor prognosis 😭💔