A Brief Resolved Unexplained Event, or BRUE, describes a sudden, concerning episode in an infant that resolves completely on its own. It is diagnosed when alarming symptoms occur, but no underlying cause is identified post-assessment. The term BRUE replaced “Apparent Life-Threatening Event” (ALTE) in 2016 for a more precise description. While frightening for caregivers, many BRUEs are ultimately benign.
What Defines a BRUE Event
A BRUE is defined as an event in infants under one year old. The episode must be brief, typically lasting less than one minute, and fully resolve, with the infant returning to their normal state before medical evaluation.
For an event to be classified as a BRUE, it must include at least one of four key characteristics: a noticeable change in breathing (absent, decreased, or irregular), a significant change in skin color (bluish or unusually pale), a marked change in muscle tone (unusual limpness or stiffness), or an altered level of responsiveness (less aware or interactive). Importantly, BRUE is a diagnosis of exclusion, applied only when no underlying medical condition explains the episode after thorough evaluation.
Infants are categorized as lower-risk or higher-risk based on criteria. Lower-risk BRUE typically occurs in infants older than 60 days, born at or after 32 weeks gestation, and with a post-conceptual age of at least 45 weeks. Such an event lasts less than one minute and does not require cardiopulmonary resuscitation (CPR).
Higher-risk BRUE applies to infants not meeting lower-risk criteria, requiring more extensive evaluation. This stratification guides appropriate investigation and management, ensuring infants with potential underlying issues receive necessary attention while avoiding excessive testing for those at lower risk.
Medical Assessment After a BRUE
When an infant experiences a suspected BRUE, a thorough medical assessment is conducted to find an underlying cause. The initial evaluation involves a detailed history of the event, focusing on the infant’s activity, color, breathing, and muscle tone during the episode. A comprehensive physical examination follows, checking for any abnormalities, signs of infection, or indications of trauma.
The assessment aims to differentiate a true BRUE from other medical conditions with identifiable causes. These can include gastroesophageal reflux, infections causing breathing difficulties, seizures, cardiac arrhythmias, and metabolic disorders.
The extent of diagnostic testing depends on the infant’s risk classification. For lower-risk infants, extensive testing is not recommended. Often, a period of observation with continuous monitoring is sufficient to ensure stability. Routine lab tests are not needed unless specific concerns arise during the history or physical exam.
For higher-risk infants, the medical evaluation becomes more targeted, guided by clinical suspicion. Specific investigations may be performed to rule out serious conditions, including:
An electrocardiogram (ECG) to assess heart rhythm.
Blood tests for infection or metabolic imbalances.
An electroencephalogram (EEG) if seizures are suspected.
Imaging studies.
Despite these investigations, a specific cause for the event is often not identified, even in higher-risk cases.
Management and Prognosis of BRUE
The management of a BRUE depends on the infant’s risk stratification. For lower-risk infants, no specific treatment or extensive follow-up is required. The primary approach focuses on parent education and reassurance. Healthcare providers emphasize safe sleep practices and advise caregivers on basic infant care.
Families of lower-risk infants are encouraged to learn infant cardiopulmonary resuscitation (CPR). This skill provides caregivers confidence to respond effectively if another event occurs, though uncommon. Follow-up with the primary care provider within a few days is often recommended to ensure continued well-being.
For higher-risk infants, management typically involves hospital observation, often with continuous monitoring of heart rate and breathing. This allows observation for symptom recurrence or subtle signs of an underlying medical condition. Further investigations and interventions are tailored to the infant’s presentation and any concerns identified during the initial assessment.
The prognosis for infants experiencing a BRUE is generally favorable. Most lower-risk BRUE events are harmless and do not lead to long-term health complications. Importantly, research indicates that a single lower-risk BRUE does not increase an infant’s risk of Sudden Infant Death Syndrome (SIDS). While a small percentage of infants who die from SIDS may have a history of prior events, this connection is typically seen in specific higher-risk scenarios or with recurrent episodes.
Parents should seek emergency care by calling 911 if their infant experiences another event involving blue or pale skin, severe breathing difficulties, marked changes in muscle tone, or unresponsiveness. For less severe but still concerning symptoms, such as persistent unusual fussiness, feeding problems, or fever, contacting their pediatrician is advisable. Understanding these guidelines can help parents navigate the anxiety associated with a BRUE and ensure their infant receives appropriate care.