RESPIRATORY CONDITIONS

Apnoea of Prematurity

A practical guide for paediatric registrars  ·  Immature respiratory control in the preterm infant

PAUSES >20s WITH
BRADY/DESAT -
EXCLUDE OTHER CAUSES
📋 AOP AT A GLANCE
📖Definition
Cessation of breathing for >20 seconds (or shorter with bradycardia/desaturation) in a preterm infant, from immature respiratory control. A diagnosis of exclusion.
📊Incidence
Very common; inversely related to gestation - nearly universal below 28 weeks.
👶At-risk infants
Preterm infants; more frequent and severe with greater prematurity.
🔀Types
Central (no effort), obstructive (effort, no airflow) and mixed - mixed is the most common.
⏱️Onset
Usually after the first 24-48h - not at birth. Apnoea in the first day, or in a term infant, suggests another cause.
📈Resolves
Typically by ~34-37 weeks corrected (later in the very preterm).
🧬 PATHOPHYSIOLOGY
1

Immature respiratory control

The brainstem respiratory centres and chemoreceptor responses are immature. The core mechanism.

2

Blunted chemoreflexes

Immature CO₂ responses; in preterm infants, hypoxia can depress rather than stimulate breathing.

3

Upper airway instability

Poor pharyngeal tone leads to obstructive and mixed events.

4

Exaggerated inhibitory reflexes

Reflexes such as the laryngeal chemoreflex can provoke apnoea.

5

A diagnosis of exclusion

Sepsis, NEC, IVH, hypoglycaemia, anaemia, reflux and temperature all cause apnoea and must be excluded.

🔬INVESTIGATIONS

  • Look for an underlying cause: sepsis screen (FBC, CRP, culture), glucose, electrolytes/calcium
  • FBC for anaemia; consider cranial ultrasound (IVH) and abdominal assessment (NEC)
  • Review feeds/reflux, drugs, positioning and temperature
  • Cardiorespiratory monitoring to characterise events
  • Imaging is normal in AOP - used only to exclude other causes

🚩COMPLICATIONS & RED FLAGS

  • Recurrent hypoxaemia and bradycardia
  • Red flag: apnoea in the first 24h, in a term infant, or a sudden change in pattern → investigate for sepsis, NEC, IVH or a metabolic cause; don't assume AOP
  • Apnoea persisting beyond the expected gestation warrants review
🧠

Why there's no "chest X-ray" panel here: AOP is a clinical diagnosis of exclusion, not an imaging one - the chest film is normal. Imaging and a septic/metabolic workup are used to rule out other causes of apnoea (sepsis, NEC, aspiration, IVH), not to confirm AOP.

MANAGEMENT

Exclude the dangerous mimics first, then treat the immature control with caffeine and, where needed, airway support.

Exclude & Support

  • First, exclude and treat underlying causes (sepsis, anaemia, hypoglycaemia, NEC, IVH, reflux, temperature)
  • Cardiorespiratory monitoring; gentle stimulation for events; correct positioning
  • Maintain SpO₂; treat anaemia

Caffeine

  • Caffeine citrate is first-line: loading ~20 mg/kg, then ~5-10 mg/kg/day maintenance
  • Reduces apnoea and the need for ventilation; the CAP trial showed less BPD and better neurodevelopmental outcomes
  • Also used to facilitate extubation

Respiratory Support

  • CPAP or high-flow for obstructive/mixed apnoea (splints the airway, maintains FRC)
  • NIPPV or ventilation for frequent severe events unresponsive to caffeine + CPAP
  • Confirm resolution before discharge (observation off support/caffeine, per local policy)
💬 DISCUSSION QUESTIONS
1

How do you distinguish apnoea of prematurity from apnoea due to another cause - and what makes you investigate?

2

What is the evidence base (CAP trial) for caffeine, and what are its benefits beyond apnoea?

3

Why does CPAP help obstructive and mixed apnoea?

4

When is it safe to stop caffeine and discharge?

🔗 RESOURCES

Take-home message: Apnoea of prematurity is recurrent pauses (>20s, or shorter with bradycardia/desaturation) from immature respiratory control, appearing after the first day in preterm infants and resolving by ~34-37 weeks. It is a diagnosis of exclusion - new or worsening apnoea should prompt a search for sepsis, NEC, IVH or a metabolic cause. Treat with caffeine (first-line, with neurodevelopmental benefits per the CAP trial) and CPAP/high-flow for obstructive events, after excluding and treating other causes.

For educational purposes only. Always align management to current ANZCOR/NRP guidelines and your local SCN/NICU or NETS protocols.

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