This is 'A Nuanced Approach to Emergency Management of Hyperkalemia' on EM Cases. Of all the electrolyte emergencies, hyperkalemia is the one that has the greatest potential to lead to cardiac arrest. And so, early in my EM training I learned to get the patient on a monitor, ensure IV access, order up an ECG, bombard the patient with a cocktail of kayexalate, calcium, insulin, B-agonists, bicarb, fluids and furosemide, and get the patient admitted, maybe with some dialysis to boot. Little did I know that some of these therapies were based on theory alone while others were based on a few small poorly done studies. It turns out that some of these therapies may cause more harm than good, and that precisely when and how to give these therapies to optimize patient outcomes is still not really known...