Brief resolved unexplained events: a new diagnosis, with implications for evaluation and management.

Brief resolved unexplained events (BRUE) are concerning episodes of short duration (typically < 1 min) characterized by a change in breathing, consciousness, muscle tone (hyper- or hypotonia), and/or skin color (cyanosis or pallor). The episodes occur in a normal-appearing infant in the first year of life, self-resolve, and have no readily identifiable explanation for the cause of the event. Previously called apparent life-threatening events (ALTE), the term BRUE was first defined by the American Academy of Pediatrics (AAP) in 2016. The criteria for BRUE carry greater specificity compared to that of ALTE and additionally are indicative of a diagnosis of exclusion. While most patients with BRUE will have a benign clinical course, important etiologies, including airway, cardiac, gastrointestinal, genetic, infectious, neurologic, and traumatic conditions (including nonaccidental), must be carefully considered. A BRUE is classified as either lower- or higher-risk based on patient age, corrected gestational age, event duration, number of events, and performance of cardiopulmonary resuscitation at the scene. The AAP clinical practice guideline provides recommendations for the management of lower-risk BRUEs, advocating against routine admission, blood testing, and imaging for infants with these events, though a short period of observation and/or an electrocardiogram may be advisable. While guidance exists for higher-risk BRUE, more data are required to better identify proportions and risk factors for serious outcomes among these patients. Conclusion: BRUE is a diagnosis with greater specificity relative to prior definitions and is now a diagnosis of exclusion. Additional research is needed, particularly in the evaluation of higher-risk events. Recent data suggest that the AAP guidelines for the management of lower-risk infants can be safely implemented.This review article summarizes the history, definitional changes, current guideline recommendations, and future research needs for BRUE. What is Known: • BRUE, first described in 2016, is a diagnosis used to describe a well-appearing infant who presents with change in breathing, consciousness, muscle tone (hyper- or hypotonia), and/or skin color (cyanosis or pallor). • BRUE can be divided into higher- and lower-risk events. Guidelines have been published for lower-risk events, with expert recommendations for higher-risk BRUE. What is New: • BRUE carries a low rate of serious diagnoses (< 5%), with the most common representing seizures and airway abnormalities. • Prior BRUE events are associated with serious diagnoses and episode recurrence.