See definition above
Extensive list of historical features to be considered from Table 2 of the original BRUE article.
Extensive list of physical exam features be considered from Table 3 of the original BRUE article.
The history in an BRUE should focus extensively on the details surrounding the<unk> , need for resuscitation, prior<unk> s, possible related medical conditions, or historic findings that may indicate prior<unk> s.
Prematurity, history of apnea, prior resp/feeding difficulties
Immunization status (particularly pertussis)
History of SIDS, cardiac abnormalities, seizures, or metabolic disease
Duration of the BRUE
Was resuscitation with CPR and rescue breaths required?
Temporal relationship with feeding, sleeping, crying, vomiting, or choking
Any episodes concerning for central versus obstructive patterns of apnea
Any progressive or episodic changes in mental status
Brief resolved unexplained event
The differential diagnosis is extensive, and although a broad workup is often started in the ED including evaluation for sepsis, occult infection, and metabolic disorders, a cause is infrequently found[2]
Deterioration after intubation
Idiopathic 
Headache during pregnancy
GERD
Acute chest pain
Seizure