BRUE (Brief Resolved Unexplained Event)
Definition and scope
BRUE describes a sudden, brief episode in an infant (< 1 year) of one or more of the following that fully resolves and for which no explanation is found after initial assessment:
- cyanosis or pallor
- absent, decreased or irregular breathing
- marked change in tone (hypotonia or hypertonia)
- altered responsiveness (reduced alertness, lethargy)
The term replaces “ALTE” (acute life‑threatening event) to encourage clearer use and avoid unnecessary testing. BRUE is a diagnosis of exclusion: if a specific cause (for example seizure, sepsis, choking, cardiac disease) is identified, manage and label the episode accordingly.
Typical event features
- Colour change (cyanosis or pallor)
- Apnoea or abnormal respiratory pattern (absent, decreased or irregular breathing)
- Marked change in tone (hypotonia or hypertonia)
- Altered responsiveness (reduced alertness, lethargy)
Immediate emergency priorities
- Resuscitate first if required. Follow paediatric basic life support and local resuscitation protocols (Resuscitation Council UK).
- If unresponsive and not breathing normally: request immediate help, call the emergency response system, start infant CPR.