Hyperkalemia reduces the firing threshold of the cardiac myocyte, which causes hyperexcitability, progressive cardiac conduction disturbance, bradycardia, and risk of life-threatening arrhythmias.

Initial EKG signs involve peaked T waves, followed by P wave flattening, PR prolongation, QRS widening, and sine wave activity, in that order. Treatment involves administering Calcium Chloride, which has no effect on potassium levels, but which stabilizes the cardiac myocyte membrane, raising the firing threshold and decreasing risk of arrhythmia or reversing existing arrhythmia caused by hyperkalemia. Central line is preferred due to tissue necrosis, if extravasated. Depending on the urgency, Calcium Gluconate can be more safely given in a peripheral IV. This should be followed with one amp bicarbonate, one amp D50, ten units regular insulin IV, and an albuterol nebulizer to reduce serum potassium.

Long acting Lokelma or Kayexalate can follow in addition to a repeat EKG and/or emergent hemodialysis, if indicated, and a thorough view of the etiology of the hyperkalemia.