From the Guidelines
Hyperkalemia is a life-threatening condition that requires immediate attention, and the most effective treatment includes administering calcium gluconate or calcium chloride to stabilize cardiac membranes, followed by sodium bicarbonate to shift potassium into cells, as evidenced by the most recent study 1.
Definition and ECG Changes
Hyperkalemia is defined as a serum potassium concentration exceeding the upper limit of normal, typically above 5.5 mEq/L. It can cause distinctive ECG changes that progress with increasing severity, including:
- Tall, peaked T waves
- PR interval prolongation
- P wave flattening
- QRS widening
- Eventually, sine wave pattern and asystole in severe cases
Treatment Options
Treatment options for acute hyperkalemia include:
- Intravenous calcium gluconate or calcium chloride to rapidly reduce the membrane excitatory effects of potassium on cardiac tissue
- Sodium bicarbonate to shift potassium into cells through increased pH
- Insulin with glucose, beta-agonists, and potassium binders or dialysis for definitive removal
Physiological Basis
The physiological basis for these interventions relates to how potassium affects cardiac cell membrane potential - hyperkalemia decreases the resting membrane potential, initially increasing excitability but eventually preventing normal depolarization, which calcium counteracts by increasing the threshold potential for depolarization, effectively stabilizing cardiac membranes until potassium levels can be reduced, as noted in 1.
Key Considerations
Key considerations in the management of hyperkalemia include:
- The severity of the condition, with more severe cases requiring more aggressive treatment
- The presence of underlying conditions, such as renal failure or metabolic acidosis, which can affect treatment choices
- The need for close monitoring of ECG changes and serum potassium levels to guide treatment, as highlighted in 1 and 1.
Recent Guidelines
Recent guidelines, such as those outlined in 1, emphasize the importance of prompt recognition and treatment of hyperkalemia to prevent cardiac arrest and other complications. The use of calcium gluconate or calcium chloride, followed by sodium bicarbonate, is a critical component of this treatment approach, as it helps to stabilize cardiac membranes and shift potassium into cells, reducing the risk of life-threatening arrhythmias.
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.
- Hyperkalemia is a condition characterized by an increased potassium level in the extracellular fluid, which can be measured by electrocardiogram (ECG) changes.
- The administration of calcium chloride can help combat the deleterious effects of hyperkalemia as measured by ECG.
- There is no direct information in the provided drug label about the role of bicarbonate in treating hyperkalemia or ECG changes.
- The use of calcium chloride to treat hyperkalemia is based on medical literature, but adequate well-controlled, randomized clinical studies have not been done to support this indication 2.
From the Research
Hyperkalemia Overview
- Hyperkalemia is a common electrolyte disorder that can result in morbidity and mortality if not managed appropriately 3
- It is defined as a condition where a serum potassium level is >5.5 mmol/l 4
- Hyperkalemia can lead to fatal dysrhythmias and muscular dysfunction, and is associated with increased mortality 4, 5
EKG Changes
- Hyperkalemia can cause various cardiac dysrhythmias, which may result in cardiac arrest and death 3
- Certain characteristic electrocardiogram findings are associated with hyperkalemia, along with laboratory potassium levels 4
- EKG changes can be used to determine whether a hyperkalemic patient requires immediate treatment to avoid a life-threatening situation 6
Treatment with Bicarbonate and Calcium
- Calcium gluconate 10% dosed 10 mL intravenously should be provided for membrane stabilization, unless the patient is in cardiac arrest, in which case 10 mL calcium chloride is warranted 3
- Sodium bicarbonate (NaHCO3) can be used as part of a regimen to cause a transcellular shift of potassium, but its efficacy as a potassium-lowering agent when used alone is poor 6
- The combination of insulin with glucose and NaHCO3 may have additive effects, but this needs further clarification 6
Other Treatment Options
- Insulin with glucose, beta(2)-agonist (albuterol), and dialysis are other treatment options for hyperkalemia 3, 4, 6
- Hemodialysis is the most efficient means to enable removal of excess potassium, and should be considered in severe hyperkalemia induced cardiac arrest if conventional therapies fail 7
- New medications to promote gastrointestinal potassium excretion, such as patiromer and sodium zirconium cyclosilicate, hold promise for the treatment of hyperkalemia 3, 4