Medical Council of Canada

Medical expert

Brief Resolved Unexplained Event (BRUE) (Previously known as Apparent Life-Threatening Event [ALTE]) - 104-1


Life-threatening events involving infants are devastating to parents, caregivers and health care workers alike. Brief resolved unexplained events (BRUE) are characterized by a non-specific, resolved and episodic presentation, including any of the following: cyanosis or pallor; absent, decreased or irregular breathing; marked change in tone (hypertonia or hypotonia; and/or altered responsiveness). The etiology of these events is heterogeneous for a majority of infants; a specific cause may be identified following a focused history, physical examination and targeted investigations.

Causal Conditions

(list not exhaustive)

An underlying etiology may be found in over half of infants presenting with BRUE. For those infants where a cause cannot be identified through a focused clinical evaluation and/or initial investigations, stratification for risk/probability of an occult pathology should guide further investigations and monitoring interventions. Possible causes of BRUE include:

  1. Misinterpretation of normal physiology in an infant (e.g., transient choking with rapid feeding or with coughing during feeding, periodic breathing/ respiratory pauses of 5-15 seconds)
  2. Infectious disease (e.g., respiratory infection, sepsis, meningitis, encephalitis)
  3. Cardiopulmonary abnormalities (e.g., central or obstructive sleep apnea, arrhythmia)
  4. Neurologic disease (e.g., epilepsy)
  5. Child abuse (e.g., intentional suffocation, non-accidental head injury)
  6. Metabolic disease (e.g., inborn error of metabolism)
  7. Other (e.g., toxic ingestion, poisoning)

Key Objectives

Given the presentation of an infant with a BRUE, the candidate will evaluate possible risk factors and/or causes and initiate an appropriate management plan including investigations, interventions and follow-up. If an etiology is not identified through the initial evaluation, the candidate will determine whether the severity of the BRUE warrants more extensive investigation through the process of risk categorization .

The candidate will also counsel the infant's parents/caregivers and family.

Enabling Objectives

Given an infant presenting with a BRUE, the candidate will

  1. list and interpret critical clinical findings, including those derived from
    1. a detailed history of the event;
    2. an evaluation of maternal, infant and environmental risk factors;
    3. the physical examination and/or direct observation;
  2. list and interpret critical investigations based upon the clinical features (e.g., viral studies, chest radiograph)
  3. construct an effective initial management plan, including
    1. admitting the patient for observation;
    2. counselling and supporting the parents' emotional needs, clarifying the difference between BRUE and sudden infant death syndrome (SIDS);
    3. referring the parents if further investigations or interventions are required (e.g., high-risk BRUE, cardiopulmonary resuscitation training for recurrent events);
    4. referring the patient for specialized care/investigations, if required (e.g., metabolic testing, cardiac evaluation).
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