From the Guidelines
Hyperkalemia can cause characteristic changes on an electrocardiogram (ECG) that progress with increasing potassium levels, and treatment should be initiated promptly when ECG changes are present, starting with calcium gluconate to stabilize the myocardium, followed by insulin with glucose to shift potassium intracellularly. The early ECG findings of hyperkalemia include tall, peaked T waves, best seen in precordial leads, and as hyperkalemia worsens, PR interval prolongation occurs, followed by P wave flattening and eventual disappearance 1. Further progression leads to QRS widening, which can resemble a bundle branch block pattern, and in severe hyperkalemia, the QRS complex continues to widen and may merge with the T wave, creating a sine wave pattern that can precede ventricular fibrillation and asystole 1. These ECG changes reflect potassium's effect on cardiac cell membrane potential and conduction. Some of the key treatment options for hyperkalemia include:
- Calcium gluconate (1-2 ampules IV) to stabilize the myocardium
- Insulin (10 units regular) with glucose (25g) to shift potassium intracellularly
- Sodium bicarbonate (1-2 ampules IV) for acidotic patients
- Nebulized albuterol (10-20mg) to further drive potassium into cells
- Definitive treatment requires potassium removal via diuretics, potassium-binding resins, or dialysis in severe cases 1. ECG monitoring should continue throughout treatment as ECG changes typically reverse in the opposite order they appeared as potassium levels normalize. It's also important to note that the use of potassium-binding agents, such as patiromer sorbitex calcium (VeltassaV) or sodium zirconium cyclosilicate (SZC), can help to lower potassium levels and enable patients to continue renin-angiotensin-aldosterone system (RAAS) inhibitor therapy 1.
From the FDA Drug Label
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.
The use of calcium chloride in the treatment of hyperkalemia is supported by medical literature, which notes its effectiveness in combating the deleterious effects of hyperkalemia as measured by ECG 2.
- Key points:
- Hyperkalemia treatment
- ECG measurement
- Calcium chloride administration However, it is noted that adequate well-controlled, randomized clinical studies have not been done to support this indication.
From the Research
Hyperkalemia and EKG Changes
- Hyperkalemia is a common electrolyte disorder that can result in morbidity and mortality if not managed appropriately, with severe effects including various cardiac dysrhythmias that may result in cardiac arrest and death 3.
- The treatment of hyperkalemia includes measures to stabilize cardiac membranes, shift potassium from extracellular to intracellular stores, and promote potassium excretion 3.
- Calcium gluconate is commonly used to stabilize cardiac membranes in patients with hyperkalemia, although its effectiveness is supported by a low level of evidence and is anecdotal 4.
- A study found that intravenous calcium gluconate therapy was effective in improving main rhythm disorders due to hyperkalemia, but not effective in nonrhythm ECG disorders due to hyperkalemia 4.
EKG Changes and Hyperkalemia Treatment
- EKG changes due to hyperkalemia can be life-threatening and require emergent treatment, with the first step being to stabilize the myocardium with calcium to resolve or mitigate the development of arrhythmias 5.
- Redistribution of potassium from the extracellular space using intravenous regular insulin and inhaled beta-2 agonists is also crucial in the treatment of severe hyperkalemia with ECG changes 5.
- A systematic review and meta-analysis found that treatment with insulin in combination with glucose, inhaled or intravenous salbutamol, or the combination reduced potassium levels, but there was no evidence to support a clinical beneficial effect of calcium for treatment of hyperkalemia 6.
Cardiac Arrest and Hyperkalemia
- Severe hyperkalemia can lead to fatal arrhythmias such as ventricular fibrillation or asystole, leading to cardiac arrest, especially in patients with renal failure 7.
- Hemodialysis should be considered in the course of cardiopulmonary resuscitation in severe hyperkalemia-induced cardiac arrest if conventional therapies fail 7.
- A case report found that prolonged cardiopulmonary resuscitation along with hemodialysis was successful in treating a patient with cardiac arrest due to hyperkalemia 7.