Respiratory Distress Syndrome (RDS)

Why is this topic important?

One of the commonest causes of respiratory distress in preterm infants and a frequent MRCPCH topic.

Definition

Respiratory distress due to surfactant deficiency causing alveolar collapse and impaired gas exchange.

Key MRCPCH Facts

• Mainly affects preterm infants

• Risk increases with decreasing gestation

• Maternal diabetes increases risk

• Antenatal steroids reduce incidence

• Surfactant therapy improves outcome

Pathophysiology

Surfactant deficiency → alveolar collapse → reduced lung compliance → hypoxia and respiratory failure.

Clinical Features

• Tachypnoea

• Grunting

• Recession

• Nasal flaring

• Increased oxygen requirement

Investigations

Chest X-ray

• Ground-glass appearance

• Air bronchograms

• Low lung volumes

Blood Gas

• Hypoxia

• Hypercapnia

• Acidosis

Management

• CPAP

• Surfactant

• Oxygen

• Mechanical ventilation if required

Complications

• Pneumothorax

• Chronic lung disease

• Intraventricular haemorrhage

Common Exam Traps

TTN usually occurs in term infants and shows increased lung volumes, not low volumes.

One Minute Revision

• Prematurity

• Surfactant deficiency

• Ground-glass lungs

• CPAP + surfactant

Related QOTD

Premature infant + ground-glass X-ray = RDS

References

1. BAPM Guidance

2. RCPCH Neonatal Guidance

3. Rennie & Roberton’s Textbook of Neonatology

4. Nelson Textbook of Pediatrics

5. BNF for Children

Disclaimer

For educational and MRCPCH revision purposes only.