What are the signs and symptoms of hyperkalemia?

From the Guidelines

Hyperkalemia is a life-threatening condition that can present with various signs and symptoms, including muscle weakness, fatigue, numbness or tingling sensations, nausea, vomiting, abdominal cramping, and diarrhea, and can cause cardiac abnormalities such as palpitations, slow heart rate, and irregular heartbeats, with the most concerning cardiac manifestations appearing on an electrocardiogram (ECG) as peaked T waves, widened QRS complexes, prolonged PR intervals, and eventually sine wave patterns that can lead to ventricular fibrillation and cardiac arrest, as noted in the 2021 study published in the Mayo Clinic Proceedings 1.

The clinical signs associated with severe hyperkalemia (more than 6.5 mmol/L) include flaccid paralysis, paresthesia, depressed deep tendon reflexes, or shortness of breath, as stated in the 2020 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care 1. The early electrocardiographic signs include peaked T waves on the ECG followed by flattened or absent T waves, prolonged PR interval, widened QRS complex, deepened S waves, and merging of S and T waves.

Some key points to consider in the management of hyperkalemia include:

• The risk of mortality, cardiovascular morbidity, progression of CKD, and hospitalization is increased in patients with hyperkalemia, especially those with CKD, HF, and diabetes, as noted in the 2021 study published in the Mayo Clinic Proceedings 1.
• The severity of hyperkalemia can be classified as mild (>5.0 to <5.5 mEq/L) to moderate (5.5 to 6.0 mEq/L) and to severe at thresholds (>6.0 mEq/L), as stated in the 2018 expert consensus document on the management of hyperkalaemia in patients with cardiovascular disease treated with renin angiotensin aldosterone system inhibitors 1.
• Individuals with kidney disease, those taking certain medications (like ACE inhibitors, ARBs, potassium-sparing diuretics), or patients with adrenal insufficiency are at higher risk and should be monitored closely for these symptoms, as noted in the 2021 study published in the Mayo Clinic Proceedings 1.
• Monitoring serum K+ should be individualized; however, increased frequency of monitoring should be considered for patients with chronic kidney disease, diabetes, heart failure, or a history of hyperkalemia and for those receiving RAASi therapy, as suggested in the 2021 study published in the Mayo Clinic Proceedings 1.

From the Research

Signs and Symptoms of Hyperkalemia

The signs and symptoms of hyperkalemia can vary depending on the severity and underlying cause of the condition. Some common manifestations include:

• Cardiac dysrhythmias, which can lead to cardiac arrest and death 2
• Alterations in the cellular transmembrane potential, causing life-threatening arrhythmias 3
• Impaired cardiovascular effects of renin-angiotensin-aldosterone system inhibitors (RAASis) and potassium-rich diets 4
• Increased risk of morbidity and mortality, especially in patients with heart failure, renal insufficiency, and/or diabetes mellitus 5, 3

Severity and Risk

The severity and associated risk of hyperkalemia depend on the underlying cause and rate of potassium increase. Acute hyperkalemia requires immediate attention due to potentially life-threatening manifestations, while chronic hyperkalemia develops over a more extended period and tends to have less severe manifestations 5.

Clinical Presentation

Hyperkalemia can be detected via serum clinical laboratory measurement, and the most severe effect includes various cardiac dysrhythmias, which may result in cardiac arrest and death 2. The clinical presentation of hyperkalemia can also include:

• Electrocardiographic changes, such as peaked T waves, PR segment prolongation, and QRS complex widening 6
• Muscle weakness, fatigue, and palpitations 3
• Numbness or tingling sensations in the extremities 4

Treatment and Management

Treatment of hyperkalemia focuses on stabilizing the cardiac membrane, shifting potassium into cells, and initiating strategies to decrease total body potassium content 2, 5. Management options include:

• Calcium gluconate or calcium chloride administration to stabilize cardiac membranes 2
• Insulin and glucose administration to shift potassium into cells 2, 6
• Beta-agonists, such as albuterol, to shift potassium into cells 2
• Potassium-binding resins, such as patiromer and sodium zirconium cyclosilicate, to decrease total body potassium content 5, 4
• Dialysis, which is the most efficient means of removing excess potassium 2