Lung

Meconium Aspiration Syndrome

search

Meconium Aspiration Syndrome, Meconium Aspiration, Meconium Aspiration Pneumonia, Meconium Pneumonitis

  • Epidemiology
  1. Prevalence
    1. Meconium-stained amniotic fluid is present in up to 15% of deliveries
    2. Meconium Aspiration Syndrome occurs in only 1% of all deliveries
  • Pathophysiology
  1. Meconium contains gastrointestinal fluids which cause localized inflammation
  2. Meconium Aspiration results in severe airway inflammation and Pneumonia risk
  3. Meconium Aspiration occurs in utero, not at delivery
  • Signs
  1. Hypoxia and Cyanosis
  2. Respiratory distress
    1. Tachypnea
    2. Grunting
    3. Retractions
  3. Lung Exam
    1. Rales and rhonchi
    2. Chest may appear barrel-shaped
  • Differential Diagnosis
  1. See Newborn Respiratory Distress
  1. Patchy Atelectasis (fluffy densities)
  2. Hyperinflation
  3. Lung consolidation changes
  • Management
  • Meconium stained infant
  1. See Respiratory Distress in the Newborn
  2. See Newborn Resuscitation
  3. Infant brought to warmer with head angled down and with minimal stimulation
  4. Oxygenation and ventilation
    1. Supplemental Oxygen 21-50% FIO2 to keep Oxygen Saturation >90%
    2. Non-Invasive Positive Pressure Ventilation (e.g. N-CPAP)
    3. Endotracheal Intubation may be required
  5. Evaluate infant for vigorous activity
    1. Vigorous infants without distress may be managed routinely
    2. Infants with Heart Rate <100 beats/min, apnea, or poor tone require intervention
      1. Intubation
      2. Suctioning
  • Prevention
  1. Suctioning head at the perineum no longer recommended
    1. See pathophysiology above regarding in utero aspiration
    2. Vain (2004) Lancet 364:597-602 [PubMed]
  2. Amnioinfusion does not decrease Meconium Aspiration risk
    1. Fraser (2005) N Engl J Med 353:909-17 [PubMed]
  • References
  1. Hermansen (2015) Am Fam Physician 92(11): 994-1002 [PubMed]