Brash syndrome

Background

via emcrit.org

• Combination of:
  • Renal failure
  • AV node blocker: beta-blocker, verapamil or diltiazem- typically adherent with medication but an overdose
  • Shock
  • Hyperkalemia
  • Bradycardia
• Vicious cycle: in setting of medications, hyperkalemia, renal failure
• Renal failure causes hyperkalemia (+/- accumulation of AV node blockers), hyperkalemia synergizes with AV node blockers to cause bradycardia and hypoperfusion, hypoperfusion worsens renal failure

Clinical Features

• Asymptomatic or symptomatic bradycardia
  • Typically appear more well than vitals/labs suggest
• Multisystem organ failure (shock, pulmonary edema, renal failure, shock liver)
• Altered mental status

Differential Diagnosis

Symptomatic bradycardia

• Cardiac
  • Inferior MI (involving RCA)
  • Sick sinus syndrome
• Neurocardiogenic/reflex-mediated
  • Increased ICP
  • Vasovagal reflex
  • Hypersensitive carotid sinus syndrome
  • Intra-abdominal hemorrhage (i.e. ruptured ectopic)
• Metabolic/endocrine/environmental
  • Hyperkalemia
  • Hypothermia (Osborn waves on ECG)
  • Hypothyroidism
    • Myxedema coma
  • Hypoglycemia (neonates)
• Toxicologic
  • B-blocker
  • Ca-channel blocker
  • Clonidine
  • Digoxin toxicity
  • Ethanol
  • Opioids
  • Organophosphates
  • Xylazine toxicity
• Infectious/Postinfectious
  • Chagas disease
  • Lyme disease
  • Syphilis
• Other
  • Brash syndrome
• See renal failure
• pure hyperkalemia
• pure AV node blocker intoxication (e.g. calcium channel blocker toxicity, beta-blocker toxicity)

Evaluation

• May have only mild hyperkalemia, with bradycardia out of proportion to degree of hyperK
• EKG: may mot have typical findings of hyperkalemia

Management

• Hyperkalemia treatment (e.g. IV insulin/dextrose, albuterol, IV calcium, kaliuresis or dialysis)
• IVF resuscitation for hypovolemia
• Catecholamines (e.g. epinepherine) for persistent bradycardia/shock
• Targeted treatments for beta-blocker or CCB overdose not helpful
• May not respond well to atropine or transcutaneous pacing

References

https://emcrit.org/pulmcrit/brash-syndrome-bradycardia-renal-failure-av-blocker-shock-hyperkalemia/