Brief Resolved Unexplained Event (BRUE) / Apparent Life-Threatening Event (ALTE)

Introduction

In this MCCQE1 preparation article, we'll explore Brief Resolved Unexplained Event (BRUE), previously known as Apparent Life-Threatening Event (ALTE). Understanding this condition is crucial for Canadian medical students preparing for the MCCQE1 exam and future clinical practice.

Definition and Terminology

BRUE Definition

A Brief Resolved Unexplained Event (BRUE) is defined as an event occurring in an infant <1 year of age when the observer reports a sudden, brief, and now resolved episode of ≥1 of the following:

• Cyanosis or pallor
• Absent, decreased, or irregular breathing
• Marked change in tone (hyper- or hypotonia)
• Altered level of responsiveness

BRUE vs. ALTE

Epidemiology in Canada

• Incidence: Approximately 0.6-2.46 per 1,000 live births
• Peak age: 8-10 weeks
• Slight male predominance (60:40)

Pathophysiology

The exact pathophysiology of BRUE is often unclear, but potential mechanisms include:

1. Gastroesophageal reflux
2. Seizures
3. Respiratory infections
4. Cardiac arrhythmias
5. Metabolic disorders

Clinical Presentation

Risk Stratification

Canadian pediatric practice follows a risk stratification approach for BRUE:

Low-Risk BRUE

• Age >60 days
• Born ≥32 weeks gestation and corrected gestational age ≥45 weeks
• No CPR required by trained medical provider
• Event duration <1 minute
• First event
• No concerning historical features or physical examination findings

High-Risk BRUE

• Any infant not meeting all low-risk criteria

Diagnostic Approach

Potential Investigations for High-Risk BRUE

1. CBC with differential
2. Electrolytes, blood glucose, blood gas
3. ECG
4. Chest X-ray
5. EEG (if seizure suspected)
6. Additional tests based on clinical suspicion

Management

Management of BRUE in Canada focuses on:

1. Risk stratification
2. Parental education and support
3. Treatment of underlying causes (if identified)
4. Follow-up care

Prognosis

• Most BRUE events are benign and do not recur
• Low-risk BRUE has an excellent prognosis
• High-risk BRUE prognosis depends on underlying etiology

Prevention and Education

1. Safe sleep practices
2. Breastfeeding promotion
3. Avoiding exposure to tobacco smoke
4. Up-to-date immunizations
5. CPR training for caregivers

Canadian Guidelines

The Canadian Paediatric Society (CPS) has adopted the American Academy of Pediatrics (AAP) clinical practice guideline on BRUE with some modifications:

1. Emphasis on shared decision-making with families
2. Consideration of social determinants of health in management decisions
3. Adaptation to the Canadian healthcare system context

Key Points to Remember for MCCQE1

• BRUE is the current term used in Canada, replacing ALTE
• BRUE applies to infants <1 year of age
• Risk stratification is crucial in management decisions
• Low-risk BRUE often requires minimal intervention
• High-risk BRUE may need comprehensive evaluation
• Canadian guidelines emphasize family-centered care and shared decision-making
• Consider social determinants of health in BRUE management
• Prognosis is generally good, especially for low-risk BRUE

Sample Question

# Sample Question

A 3-month-old male infant is brought to the emergency department by his parents after a brief episode of pallor and limpness that resolved spontaneously. The event lasted approximately 30 seconds, and the infant is now alert and well-appearing. This is the first such event, and the infant was born at term with no significant medical history. Which one of the following is the most appropriate next step in management?

- [ ] A. Admit for 24-hour observation and continuous cardiorespiratory monitoring
- [ ] B. Perform a full septic workup, including lumbar puncture
- [ ] C. Order an EEG to rule out seizure activity
- [ ] D. Provide caregiver education and discharge home with follow-up
- [ ] E. Obtain a sleep study to evaluate for obstructive sleep apnea

Explanation

The correct answer is:

• D. Provide caregiver education and discharge home with follow-up

This scenario describes a low-risk Brief Resolved Unexplained Event (BRUE). The infant meets all criteria for low-risk BRUE:

• Age >60 days (3 months old)
• Born at term (≥37 weeks gestation)
• No CPR required
• Event duration <1 minute (30 seconds)
• First event
• No concerning historical features or physical examination findings mentioned

For low-risk BRUE, Canadian guidelines, in line with AAP recommendations, suggest minimal intervention. Caregiver education about BRUE, safe sleep practices, and CPR training is appropriate. Discharge with follow-up is recommended for these cases.

Option A (admission) is not necessary for low-risk BRUE. Option B (full septic workup) is overly aggressive for a well-appearing infant with no signs of infection. Option C (EEG) is not routinely recommended for low-risk BRUE without specific concerns for seizure. Option E (sleep study) is not indicated as a first-line investigation for BRUE.

This question tests the candidate's ability to recognize low-risk BRUE and apply appropriate management strategies in the Canadian healthcare context, aligning with MCCQE1 objectives and the CanMEDS framework.

References

1. Tieder, J. S., Bonkowsky, J. L., Etzel, R. A., et al. (2016). Brief Resolved Unexplained Events (Formerly Apparent Life-Threatening Events) and Evaluation of Lower-Risk Infants. Pediatrics, 137(5), e20160590. Link (opens in a new tab)

2. Canadian Paediatric Society. (2017). Brief resolved unexplained events (formerly apparent life-threatening events). Paediatrics & Child Health, 22(4), 202-204. Link (opens in a new tab)

3. Arane, K., Claudius, I., & Goldman, R. D. (2017). Brief resolved unexplained event: New diagnosis in infants. Canadian Family Physician, 63(1), 39-41. Link (opens in a new tab)

4. Zentner, D., Eiley, K., & Wong, A. (2019). Brief resolved unexplained events in Canadian children: Are we following the guidelines? Paediatrics & Child Health, 24(3), e126-e132. Link (opens in a new tab)

5. Health Canada. (2021). Safe Sleep for Your Baby. Link (opens in a new tab)