BRUE (Brief, Resolved, Unexplained Event) By Christopher P Raab, MD, Sidney Kimmel Medical College at Thomas Jefferson University Reviewed / Revised Feb 2023 View Patient Education Evaluation Treatment Prognosis Key Points More Information Topic Resources Tests for High-Risk Infants... BRUE (brief, resolved, unexplained event) is an episode of cyanosis or pallor, abnormal breathing, abnormal muscle tone, or altered responsiveness in infants.