BRUE (brief, resolved, unexplained events) is not a specific disorder. It is a term used to describe a sudden episode of a change in breathing, a change in color, a change in muscle tone, or a change in the level of responsiveness in infants under 1 year of age.
An event is classified as a BRUE if no cause of the symptoms is found after an initial, thorough medical evaluation.
Similar symptoms may be caused by digestive, nervous system, breathing, infectious, heart, and metabolic disorders as well as by physical trauma.
The diagnosis is based on a discussion with caregivers, a physical examination, and sometimes the results of certain laboratory tests.
Treatment is aimed at specific causes, if they are identified.
Sometimes infants have episodes of symptoms that raise concern about their health. Previously, doctors used the term "apparent life-threatening event" (ALTE) to describe all events where infants suddenly developed symptoms that alarmed the person who witnessed the event. Now, doctors refer to such events as brief, resolved, unexplained event (BRUE). The current term is focused on efforts to find a cause of the event rather than on the perception that it is life threatening.
BRUE describes episodes that occur only in children under 1 year of age:
B = Brief: The event lasts for less than 1 minute.
R = Resolved: The event ends and the child returns to a normal state of health.
U = Unexplained: No cause can be found after a doctor's evaluation.
E = Event: The child has symptoms such as changes in breathing or a period of no breathing (apnea), a change in color, a change in muscle tone, and/or a change in the level of responsiveness.
Such episodes may seem to be related to sudden unexplained infant death (SUID) and sudden infant death syndrome (SIDS), but BRUE is a separate diagnosis that has different risk factors and tends to affect infants at different ages and in different circumstances.
Symptoms of BRUE
A BRUE is characterized by an unexpected, sudden change in an infant that alarms the parent or caregiver.
Features of a BRUE that may alarm a parent or caregiver include some or all of the following:
Breathing that pauses for 20 seconds or more (apnea), breathing that is irregular, or no breathing at all
Color change, blue or pale
Change in muscle tone, too stiff or floppy
Change in the level of responsiveness (for example, drowsiness, inactivity, or loss of consciousness)
Causes of symptoms similar to BRUE
A cause for these alarming symptoms is determined in about half of affected infants. When a cause for the symptoms is identified during a medical evaluation, the episode is not considered a BRUE.
When a cause exists, the most common possible causes include:
Digestive disorders: Gastroesophageal reflux disease or difficulty swallowing
Nervous system disorders: Seizures or brain tumors, breath holding, or hydrocephalus
Breathing disorders: Caused by, for example, respiratory syncytial virus, influenza (flu), or pertussis
Infections: Sepsis or meningitis
Less common possible causes include:
Heart disorders
Metabolic disorders
Narrowing or complete blockage of the airways (obstructive sleep apnea)
Other causes (including substances such as alcohol and medications such as over-the-counter cold medications, child abuse, or an anaphylactic reaction)
Diagnosis of BRUE
A doctor's evaluation
Other testing based on the results of the evaluation
When an episode with symptoms of BRUE occurs, the doctor asks several key questions:
What was observed by the caregiver who witnessed the event (including a description of changes in breathing, color, muscle tone, and eyes, noises made, length of the episode, and symptoms that occurred before the event)?
What interventions were taken (such as gentle stimulation, mouth-to-mouth breathing, or cardiopulmonary resuscitation [CPR])?
Did the mother take medications or use recreational drugs while pregnant? Do current caregivers or members of the family currently use illicit drugs, tobacco, or alcohol?
What was the child's gestational age (the number of weeks of pregnancy)? Were there any complications at birth?
While feeding, does the child gag, cough, or vomit? Has poor weight gain been an issue?
Has the child reached all age-appropriate developmental milestones and growth milestones?
Has the child had a similar episode before or had a recent injury or infection?
Have there been any similar events, early deaths, or abnormal heart rhythms in the family?
The doctor does a physical examination to check for obvious abnormalities, particularly nervous system abnormalities, such as being too stiff (posturing), having low muscle tone (floppy), or having muscles that are stiff or move in a jerky fashion (spastic), and for signs of infection, injury, or suspected child abuse.
Based on the discussion with the caregivers and the physical examination, the doctor may have enough information to ensure the child is at low or high risk of having a serious medical condition. If the risk is low, the child may need only brief (1- to 4-hour) monitoring of their blood oxygen level and sometimes an electrocardiogram or a test for pertussis. If the risk is high, additional testing, monitoring, or both is recommended.
Sometimes the doctor may do laboratory tests (such as blood tests to check for anemia or infection and tests for kidney and liver function, as well as stool, urine, and spinal fluid studies), imaging tests (such as a chest x-ray or computed tomography [CT] scan of the head), electrocardiogram, or a combination of tests based on the infant's examination findings. Other tests to check for possible seizure activity (such as an electroencephalogram) also may be done.
Treatment of BRUE
Treatment of identified causes
Education for parents or caregivers
The cause, if identified, is treated.
Infants who needed CPR after the episode, had any abnormalities identified during the examination or laboratory testing, or whose history is concerning to the doctor are hospitalized for monitoring and further evaluation.
Parents and caregivers should be educated about BRUEs and trained in CPR for infants and in general safe infant care such as putting infants to sleep on their back.
Exposure to smoking is a risk factor for BRUE, so infants should not be exposed to tobacco smoke.
Prognosis for BRUE
The risk of serious complications after a low-risk BRUE is quite small and the outlook is reassuring.
About 10% of infants with BRUE will have another BRUE in the future. Infants who are hospitalized after a BRUE have a higher risk of having another one. However, death is not at all likely.
More Information
The following English-language resource may be useful. Please note that The Manual is not responsible for the content of this resource.
