Intravenous potassium infusion is usually reserved for serum potassium levels ≤2.5 mEq/L. This is because intravenous potassium can be irritating to veins during infusion and is associated with a risk of cardiac rhythm abnormalities during infusion. It is reserved for more severe cases of hypokalemia because it will rapidly replete potassium—faster than oral potassium. The trade-off of speed, though, is a risk. Therefore, cardiac monitoring should be in place during intravenous potassium infusion. Importantly, cardiac monitoring should be in place for anyone with severe hypokalemia because this level of potassium can, itself, cause ECG abnormalities.