Respiratory distress syndrome

• Affects 75% of infants born before 29 weeks - born before the lungs start producing adequate surfactant

Pathophysiology

• Inadequate surfactant leads to high surface tension within alveoli
• This leads to atelectasis (lung collapse), as it is more difficult for the alveoli and the lungs to expand
• This leads to inadequate gaseous exchange, resulting in hypoxia, hypercapnia (high CO2) and respiratory distress

Clinical features

• Respiratory distress - tachypoea, grunting, intercostal recessions, nasal flaring, cyanosis
• Worsens over minutes to hours til 2-4 days then gradual improvement

Management

• Maternal steroid
• Surfactant replacement
• Ventilation (non-invasive preferred over invasive)

Other causes of newborn respiratory distress

• Metabolic: acidosis, inborn errors of metabolism, hypoglycaemia
• Haematological: polycythaemia, blood loss/anaemia
• Neurological: seizures, intracranial bleed, withdrawal
• Congenital: congenital lung malformations e.g. CCAM
• Anatomical abnormalities: e.g. chest wall deformities