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Acute events in infancy including brief resolved unexplained event (BRUE)

Michael J Corwin, MD
Section Editors
George B Mallory, MD
Stephen J Teach, MD, MPH
Teresa K Duryea, MD
Deputy Editor
Alison G Hoppin, MD


Infants who present with a history of an acute event (an unexpected change in an infant's breathing, appearance, or behavior), reported by their parent or caregiver, represent a heterogeneous group of patients of varying ages with diverse pathophysiology. It is not a specific diagnosis, but rather a "chief complaint" that brings an infant to medical attention. The clinical challenge is to identify the infants who may benefit from further testing and prolonged observation, based on factors that suggest an identifiable underlying diagnosis or risk for subsequent events, while avoiding unnecessary testing, monitoring, and hospital admission for the many other infants without these characteristics.

In the past, these events were termed "apparent life-threatening events" (ALTE). This term was broad and included a wide range of events and prognoses. Other previously used terms were "near-miss sudden infant death syndrome (SIDS)" or "aborted crib deaths," which were discarded because they incorrectly implied a direct association between these symptoms and SIDS [1,2].

A majority of these events are more precisely described as a "brief resolved unexplained event" (BRUE). This term was defined by consensus in 2016 and should be used instead of ALTE whenever the event is transient and remains unexplained after an appropriate medical evaluation [3]. Most but not all infants with BRUE are at low risk for recurrence or for having a serious underlying problem.  

Because of the diverse presentations, causes, and prognoses of infants presenting with acute events, evaluation and management should be individualized. This topic review outlines the primary diagnostic considerations and a stepwise plan for evaluating infants presenting with this chief complaint.


Brief resolved unexplained event (BRUE) — BRUE is not a specific diagnosis but a description of a sudden, brief, and now resolved episode in an infant that includes one or more of the following features (table 1) [3,4]:

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Literature review current through: Nov 2017. | This topic last updated: Aug 16, 2017.
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