Clinical characteristics of BRASH syndrome: Systematic scoping review

Background: Bradycardia, renal failure, atrioventricular (AV) nodal blockade, shock, and hyperkalemia (BRASH) syndrome is a recently-established entity precipitated by medication-induced AV nodal blockade. Despite its serious consequences, including death, clinical presentations, risk factors, and outcomes of the syndrome have not been well defined. We aim to summarize the existing evidence of BRASH syndrome. Methods: According to the PRISMA Extension for Scoping Reviews, we performed a search on MEDLINE and EMBASE for articles with keywords including"BRASH syndrome" and "bradycardia, renal failure, atrioventricular nodal blockade, shock, and hyperkalemia," from the inception of these databases to March 4, 2022. Results: 34 articles, including one observational study, 15 conference abstracts, and 18 case reports and case series, were included. While most patients were on beta blockers (83.3%) or calcium channel blockers (45.2%), other medications such as amiodarone were identified as precipitating agents. Atropine or glucagon were ineffective in reversing patients' symptoms, and 59.5% required inotropes or chronotropes. 7.1% expired due to BRASH syndrome. Conclusions: This systematic review summarizes the clinical characteristics of BRASH syndrome. Further studies to identify risks associated with the onset of BRASH syndrome and awareness of the critical syndrome are warranted.