Abstract
Hyperkalemia represents one of the most important acute electrolyte abnormalities, due to its potential for causing life-threatening arrhythmias. In individuals with normal kidney function hyperkalemia occurs relatively infrequently, but it can be much more common in patients who have certain predisposing conditions. Patients with chronic kidney disease are the most severely affected group, by virtue of their decreased ability to excrete potassium and because they commonly have additional predisposing conditions that often cluster within patients with chronic kidney disease. These conditions include comorbidities (e.g., diabetes mellitus) and the use of various medications, of which the most important are renin-angiotensin-aldosterone system inhibitors (RAASis). Hyperkalemia is associated with increased risk for all-cause mortality and for malignant arrhythmias such as ventricular fibrillation. The increased risk for adverse outcomes is observed even in serum potassium ranges that are often not considered targets for therapeutic interventions. The heightened risk of mortality associated with hyperkalemia is present in all patient populations, even those in whom hyperkalemia occurs otherwise rarely, such as individuals with normal kidney function.