How should I evaluate and manage an infant with a brief resolved unexplained event (BRUE)?

Evaluation and Management of Infants with BRUE

For infants presenting with a Brief Resolved Unexplained Event (BRUE), first determine if they meet lower-risk criteria—if so, minimal testing is needed and most can be safely discharged after brief observation; if they are higher-risk, pursue targeted evaluation based on specific clinical concerns rather than routine screening. 1

Definition and Initial Classification

BRUE is defined as a sudden, brief (< 1 minute), now-resolved episode in an infant < 1 year old involving at least one of: cyanosis/pallor, absent/decreased/irregular breathing, marked tone change (hyper- or hypotonia), or altered responsiveness—with no explanation after thorough history and physical examination. 1, 2

Critical distinction: If you identify a cause (fever, nasal congestion, respiratory distress, choking after vomiting), it is NOT a BRUE—treat the identified condition instead. 2

Risk Stratification: Lower-Risk vs Higher-Risk

Lower-Risk Criteria (ALL must be met): 1

• Age > 60 days
• Gestational age ≥ 32 weeks AND postconceptional age ≥ 45 weeks
• First event (no prior episodes)
• Event duration < 1 minute
• No CPR required by trained medical provider
• Normal history and physical examination

If even ONE criterion is not met, the infant is higher-risk and requires individualized evaluation. 1

Management of Lower-Risk Infants

What NOT to Do (Strong Recommendations):

Do not obtain the following tests in lower-risk infants: 1

• No CBC, blood culture, or lumbar puncture (Grade B, Strong)—serious bacterial infections are exceedingly rare in truly lower-risk infants who appear well 1
• No urinalysis (Grade C, Weak)—unless specific urinary symptoms present 1
• No chest radiograph (Grade B, Moderate)—respiratory infections present with obvious clinical signs 1
• No EEG (Grade C, Weak)—seizures are unlikely without post-ictal period or abnormal neurologic exam 1

What TO Consider:

Pertussis testing: Obtain nasopharyngeal swab for pertussis PCR if any exposure history, paroxysmal cough in contacts, or incomplete immunization status. 1

Brief observation period: Monitor for 1-4 hours in the emergency department or clinic to ensure stability and provide caregiver education. 1

Discharge criteria: Lower-risk infants with normal vital signs, normal feeding, and reassured caregivers can be safely discharged home without admission. 1, 3

Evaluation of Higher-Risk Infants

Prioritize Time-Sensitive Diagnoses First: 4

Child maltreatment assessment (highest priority):

• Examine for bruising (especially in non-mobile infants), retinal hemorrhages if concerning history, skeletal survey if < 2 years with unexplained injuries 4
• Review social history: previous CPS involvement, domestic violence, substance abuse in household, mental illness in caregivers 1

Cardiac evaluation:

• Obtain 12-lead ECG if family history of sudden death < 35 years, long QT syndrome, arrhythmias, or syncope 1, 4
• Consider cardiology consultation if QTc > 460 ms or other ECG abnormalities 4

Infectious workup (if age < 60 days or appears ill):

• Full sepsis evaluation including CBC, blood culture, urinalysis/culture, lumbar puncture 4
• Pertussis testing regardless of immunization status 1, 4
• RSV/viral testing if respiratory symptoms present 1

Secondary Evaluation (Less Time-Sensitive): 4

Neurologic assessment:

• Video EEG if post-ictal somnolence, developmental delay, abnormal tone, or recurrent stereotyped events 5, 4
• Brain MRI if abnormal head size, developmental delay, or abnormal EEG 5

Airway evaluation:

• Flexible laryngoscopy if stridor, feeding difficulties, craniofacial anomalies (micrognathia, cleft palate) 5, 4
• Polysomnography if recurrent events, witnessed apnea, or concern for obstructive sleep apnea 5

Metabolic screening:

• Consider if developmental delay, failure to thrive, or family history of metabolic disease 1, 4

Key Historical Red Flags: 1

• Age < 60 days (highest risk group)
• Prematurity (especially < 32 weeks gestation)
• Multiple events (recurrent episodes)
• CPR required by trained provider
• Event > 1 minute duration
• Family history: sudden infant death, unexplained deaths < 35 years, long QT syndrome 1

Common Pitfalls to Avoid:

Do not confuse normal infant physiology with BRUE: Periodic breathing, brief color changes with crying, normal startle reflexes, and gastroesophageal reflux without respiratory compromise are NOT BRUEs. 2, 6

Do not over-test lower-risk infants: The 2016 AAP guidelines specifically aim to reduce unnecessary testing, hospitalization, and costs in this population. 1

Do not discharge higher-risk infants without targeted evaluation: Infants not meeting all lower-risk criteria require admission or coordinated outpatient follow-up with subspecialty involvement. 4

Prognosis:

Lower-risk infants have excellent long-term outcomes with no increased mortality, normal developmental trajectories, and low recurrence rates (< 5%). 7, 3 Higher-risk infants require individualized assessment, but most do not have serious underlying pathology. 8