Infant respiratory distress syndrome (IRDS)

Definition:-
Infant respiratory distress syndrome (IRDS), also called neonatal respiratory distress syndrome (NRDS), respiratory distress syndrome of newborn, or increasingly surfactant deficiency disorder (SDD), and previously called hyaline membrane disease (HMD) is a syndrome in premature infants (< 34 weeks) caused by developmental insufficiency of pulmonary surfactant production and structural immaturity in the lungs.

" Major cause of death in premature infants"

Aetiology

Surfactant:

• Production:
  • Produced by type II alveolar cells
  • Starts at 20 weeks gestation
  • Peaks at 35 week gestation
    • Therefore any neonate < 35 week is prone to develop RDS
• Function:
  • ↓ surface tension in the alveoli
    

    Pathophysiology

    ↓ Surfactant
    ↓
    ↓ Oxygenation + ↑ Work of breathing
    ↓
    Hypoxemia + Acidosis
    ↓
    Pulmonary vasoconstriction
    ↓
    Right-to-left shunting
    (Across foramen ovale)
    [ALVEOLI]
    Ischemic damage
    ↓
    Protein transudation
    ↓
    Formation of hyaline membrane
    
    
    
    

  • Clinical features

    Occurs within the first 6 hr of life

  • Tachypnea
  • Chest retractions
  • Grunting
  • Cyanosis
  • Decreased air entry

  Diagnosis

  Imaging

  X-ray

• Reticulogranular pattern
• Ground glass opacity
• Low lung volume
• Air bronchogram
• Severe cases:
  • Whiteout lungs

Management

Prevention

Antenatal steroids

• Given to mothers in preterm labour (
• Reduces RDS, intraventricular haemorrhage and mortality in preterm neonates

Treatment

Admit to Neonatal intensive care unit (NICU)

Mild-to-moderate RDS

• Continuous positive airway pressure (CPAP)
• Surfactant:
  • INtubated, given SURfactant and rapidly Extubated (lnSurE approach) to CPAP

Severe RDS

• Mechanical ventilation