Assessment and causes of neonatal respiratory distress
THE CONTEXT
Gestation, timing of onset, severity, and associated clinical findings help identify the cause of neonatal respiratory distress. The target also includes growth-monitoring guidance and the local reaction to BCG vaccination.
Diagnostic approach
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Assess the neonate's gestation, age at onset, severity of distress, and associated clinical features.
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Chest retractions are mild or absent when respiratory distress has a non-respiratory cause.
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Downe’s Score provides an objective assessment of respiratory distress.
Non-pulmonary causes of rapid breathing
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Cardiac causes include congestive heart failure and congenital heart disease.
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Metabolic causes include hypothermia, hypoglycemia, and metabolic acidosis.
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Central nervous system causes include asphyxia, cerebral edema, and hemorrhage.
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Chest wall causes listed are asphyxiating thoracic dystrophy and Werdnig-Hoffman disease.
Pulmonary causes and distinguishing features
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Respiratory distress syndrome begins in the first 6 hours of life and is common in preterm neonates.
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Meconium aspiration syndrome begins in the first few hours. It is common in term, post-term, and small-for-date babies, with a history of meconium-stained liquor.
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Pneumonia may occur at any age and is often bacterial.
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Transient tachypnea of newborn begins within 6 hours after birth, produces tachypnea with minimal distress, and lasts 48–72 hours.
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Pneumothorax may occur at any age and causes sudden deterioration, usually during assisted ventilation.
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Tracheoesophageal fistula and diaphragmatic hernia may present at any age and may have associated malformations. Polyhydramnios is associated with esophageal atresia.
Growth monitoring and BCG reaction
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Use Fenton’s chart for preterm infants up to 50 weeks postmenstrual age, then switch to the WHO chart. Term infants use the WHO growth chart.
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Following BCG vaccination, a papule forms in 2–3 weeks, ulcerates, and later heals with a scar measuring 4–8 mm in diameter.