From a presentation at AHA 2016:
Introduction: Potassium-based cardioplegia is used in the operating theater to induce asystole. This effect is rapidly reversed with wash-out of the potassium resulting in resumption of electrical activity. This retrospective study examined 5 patients with refractory ventricular fibrillation (VF) cardiac arrest who achieved normal sinus rhythm after chemical defibrillation with exogenous KCl or resolution of endogenous hyperkalemia.
Methods: From December 2015 to May 2016, 19 patients were transported to the University of Minnesota in ongoing refractory VF as part of the Minnesota Resuscitation Consortium Advanced Perfusion and Reperfusion Cardiac Life Support Strategy. ECMO was initiated on arrival. Coronary angiography was performed and significant coronary artery disease was treated as necessary. Three patients had continued VF despite multiple shocks and treatment with amiodarone, lidocaine, metoprolol, and propofol. These patients were given KCl 0.5 mEq/kg bolus as salvage therapy after 90-120 minutes of VF. Defibrillation was administered as needed…
Results: Of the 3 patients that received exogenous potassium bolus, 2 achieved sustained ROSC. The third patient suffered recurrent VF after 30 seconds of sinus rhythm and went on to die. One of the 2 patients that achieved ROSC survived to hospital discharge while 1 patient suffered severe anoxic brain injury and died. The average peak potassium level in these 3 patients was 7.2 mmol/L with normalization within 25 minutes. The EKG showed asystole immediately after treatment with spontaneous return of normal sinus rhythm within 10 minutes.