Infant Respiratory Distress

Overview – Infant Respiratory Distress

Infant respiratory distress is a critical neonatal presentation characterised by increased work of breathing and impaired gas exchange. It commonly occurs in preterm infants but can affect term and post-term babies as well. Rapid identification of the underlying cause—such as surfactant deficiency, infection, or meconium aspiration—is essential for timely and life-saving intervention. This topic is especially important for junior doctors and midwives managing newborns in delivery suites, postnatal wards, and neonatal intensive care units.

Definition

• Preterm: <37 weeks gestation
• Term: 37–42 weeks
• Post-term: >42 weeks
• Viability thresholds:
  • <23 weeks or <500g → Non-viable (not legally obligated to resuscitate)
  • ≥24 weeks and >500g → Viable (resuscitation required)

Aetiology

Primary Causes (Most Common by Gestational Age)

• Preterm infants:
  • Surfactant Deficiency (Hyaline Membrane Disease / Neonatal Respiratory Distress Syndrome)
• Term infants:
  • Infection – Pneumonia (Group B Streptococcus, Chlamydia trachomatis)
• Post-term infants:
  • Meconium Aspiration Syndrome

Other Common Causes

• Transient Tachypnoea of the Newborn (TTN) – benign, self-limiting
• Aspiration (e.g. blood, milk, meconium)
• Pneumothorax (can result from overventilation)
• Pleural Effusion (secondary to congenital heart failure, anaemia)

Rare Causes

• Cystic Fibrosis
• Congenital Cyanotic Heart Diseases
• Neuromuscular disorders (e.g. Myasthenia Gravis, Muscular Dystrophies)

Clinical Features

Signs of Respiratory Distress

• Tachypnoea: Primary compensatory mechanism (newborns cannot increase tidal volume)
• Tachycardia → Bradycardia: Early compensation followed by failure
• Accessory muscle use:
  • Head bobbing (sternocleidomastoid activation)
  • Intercostal and supraclavicular recession
  • Tracheal tugging
  • Subcostal recession (Harrison’s sulcus)
• Nasal flaring
• Grunting: Autonomic Valsalva to maintain positive end-expiratory pressure

Signs of Decompensation

• Bradycardia
• Cyanosis
• Oxygen desaturation

Summary – Infant Respiratory Distress

Infant respiratory distress refers to a range of signs indicating difficulty with ventilation and oxygenation in newborns. The most common causes vary with gestational age—ranging from surfactant deficiency in preterm babies to infection and meconium aspiration in term and post-term infants. Early recognition of red flags such as grunting, nasal flaring, and recession is crucial. For a broader context on neonatal care, see our Obstetrics Overview page.