Description

• Brief resolved unexplained event (BRUE) is a term suggested by the American Academy of Pediatrics (AAP) to replace the term apparent life-threatening event (ALTE).
• BRUE is a resolved episode in an infant <1 year of age that was sudden, brief, and characterized by any of the following:
  • Absent, decreased, or irregular breathing
  • Cyanosis or pallor
  • Marked change in muscle tone (hyper- or hypotonia)
  • Altered responsiveness
• ALTE was originally described in 1986.
  • It disassociated apnea, color change, change in tone, choking or gagging with sudden infant death syndrome (SIDS), and triggered a research agenda for managing these patients.
  • It was faulted for including diagnoses such as choking or gagging, including actively symptomatic patients, and labeling an event as “life-threatening” without clear justification.
• BRUE, by contrast, is used to describe a well-appearing patient with an event and symptoms that have resolved by the time of presentation to a medical practitioner.
  • Identifies low risk for recurrence or a serious underlying disorder based on:
    • Age >60 days
    • Born ≥32 weeks’ gestation and have corrected age ≥45 weeks
    • No CPR performed by trained medical provider
    • Event lasting <1 minute
    • First event
  • Offers management recommendations for lower risk patients

Epidemiology

• 43% of healthy term infants have at least one 20-second apneic episode over a 3-month period.
• 5.3% of parents recall seeing apnea.
• 0.2–0.9% of infants have an episode of apnea that results in an admission to the hospital.

Risk Factors

A greater risk for a future adverse event and/or serious underlying diagnosis is conferred by:

• Prematurity and <45 weeks postconceptual age
• Age ≤60 days
• Multiple events
• Events lasting >1 minute
• CPR by trained medical provider
• Suspected child maltreatment

Pathophysiology

No unifying pathophysiology because of the numerous potential presentations and underlying diagnoses

• Central apnea: disrupted propagation of respiratory signals from the brainstem along the descending neuromuscular pathways. Example diagnoses with similar presentations include:
  • Apnea of prematurity
  • Congenital central hypoventilation syndrome
• Obstructive apnea: neuromuscular respiratory effort disrupted by an occluded airway. Example diagnoses with similar presentations include:
  • Obstructive sleep apnea
  • Pierre Robin
• Mixed apnea: combination of central and obstructive apnea. Example diagnoses with similar presentations include:
  • Laryngomalacia with a sedating ingestion
  • Prematurity with superimposed upper respiratory viral infection
• Color change from decreased oxygenation or differential blood flow. Example diagnoses with similar presentations include:
  • Cyanotic heart disease
  • Acrocyanosis
• Altered muscle tone from central or autonomic nervous system disruption. Examples include:
  • Seizure
  • Breath-holding spell
• Altered responsiveness from effects on the cerebral hemispheres and/or reticular activating system. Example diagnoses with similar presentations include:
  • Toxic ingestion
  • Traumatic brain injury

Etiology

By definition, a BRUE is unexplained. ALTE could have had multiple different etiologies or be labeled as idiopathic.