Overview
Hyperkalemia at a Glance
Hyperkalemia is a potassium concentration of at least 5.5 mmol/L or mEq/L.
Hyperkalemia is a potassium concentration of at least 5.5 mEq/L or mEq/L. Mild hyperkalemia is 5.5–5.9, moderate is 6.0–6.4, and severe is at least 6.5. Acute treatment is instituted at 5.5 or higher, but the immediate priority depends on the ECG, symptoms, rate of rise, kidney function, and overall stability rather than the number alone. [1] The danger is electrical. A patient may look comfortable while potassium is slowing conduction and preparing the heart for ventricular fibrillation or asystole. A normal ECG does not make severe hyperkalemia safe; at least half of patients with potassium at least 6.5 have no ECG changes. The emergency sequence is therefore deliberate: place the patient on cardiac monitoring and obtain a 12-lead ECG, stabilize the myocardium with IV calcium when hyperkalemic ECG changes are present, shift potassium into cells with insulin–glucose and adjunctive nebulized albuterol, then arrange potassium removal and monitor for treatment complications and rebound. [1,2]