From the Guidelines
Calcium is administered for hyperkalemia to rapidly counteract the cardiac effects of elevated potassium levels, with intravenous calcium gluconate or calcium chloride given over 2-5 minutes in emergency situations. This intervention is based on the most recent and highest quality study available, which emphasizes the importance of promptly addressing the cardiac risks associated with hyperkalemia 1. The administration of calcium works by stabilizing cardiac cell membranes and antagonizing the effects of hyperkalemia on the heart's electrical conduction system, thereby minimizing the potential for cardiac arrhythmia. Key points to consider in the management of hyperkalemia include:
- The protective effect of calcium begins within minutes but only lasts 30-60 minutes, making it a temporary measure while other treatments address the underlying potassium excess.
- Calcium does not lower serum potassium levels; it only protects against cardiac arrhythmias.
- This intervention is particularly crucial when ECG changes (peaked T waves, widened QRS, prolonged PR interval) are present, indicating cardiac involvement.
- Calcium should be administered cautiously in patients taking digoxin as it may potentiate digoxin toxicity.
- For ongoing management, additional treatments like insulin with glucose, beta-agonists, or dialysis are needed to actually reduce potassium levels, as highlighted in recent clinical guidelines 1.
From the FDA Drug Label
CLINICAL STUDIES Medical literature also refers to the administration of calcium chloride in the treatment of magnesium intoxication due to overdosage of magnesium sulfate, and to combat the deleterious effects of hyperkalemia as measured by electrocardiogram (ECG), pending correction of the increased potassium level in the extracellular fluid.
We give calcium for hyperkalemia to combat its deleterious effects on the heart, as measured by electrocardiogram (ECG), while waiting for the potassium level to be corrected in the extracellular fluid 2.
- The main goal is to counteract the cardiac effects of hyperkalemia.
- Calcium chloride is used for this purpose, although well-controlled studies are lacking.
From the Research
Treatment of Hyperkalemia
- Hyperkalemia is a common electrolyte disorder that can result in morbidity and mortality if not managed appropriately 3.
- The treatment of hyperkalemia includes measures to stabilize cardiac membranes, shift potassium from extracellular to intracellular stores, and promote potassium excretion 3, 4.
Role of Calcium in Hyperkalemia Treatment
- Calcium gluconate is commonly administered to stabilize cardiac membranes in patients with hyperkalemia 3, 4.
- However, a recent study suggests that the beneficial effect of calcium treatment for hyperkalemia is not due to "membrane stabilization" but rather to the restoration of conduction velocity through calcium-dependent propagation 5.
- Another study found no evidence to support a clinical beneficial effect of calcium for the treatment of hyperkalemia 6.
Other Treatment Options
- Insulin and glucose are commonly used to shift potassium from extracellular to intracellular stores 3, 4.
- Beta-2 agonists, such as salbutamol, can also be used to augment the effects of insulin and glucose 3, 4.
- Dialysis is the most efficient means of removing excess potassium from the body 3.
- New medications, such as patiromer and sodium zirconium cyclosilicate, have been developed to promote gastrointestinal potassium excretion 3, 7.