Hyperkalaemia

A condition characterised by an abnormally high concentration of potassium in the blood. Potassium is a critical electrolyte necessary for the normal function of nerve and muscle cells, particularly heart muscle cells.

• Typically range from 3.5 to 5.0 mmol/L.
• Hyperkalaemia is generally defined as a serum potassium level greater than 5.0 mmol/L.

High potassium levels can disrupt cellular electrical activity, especially in the heart, leading to cardiac rhythm disturbances.

• Reduced renal excretion due to acute or chronic kidney disease.
• Medications that affect renal potassium excretion (e.g., ACE inhibitors, NSAIDs, potassium-sparing diuretics).
• Excessive potassium intake (less common).
• Cellular release of potassium in response to tissue breakdown, acidosis, or hyperglycaemia.

• Often asymptomatic, particularly in mild cases.
• Muscle weakness, fatigue, and paralysis with severe hyperkalaemia.
• Cardiac manifestations include palpitations, arrhythmias, and in severe cases, cardiac arrest.

• Serum potassium measurement.
• ECG changes can provide early indications of hyperkalaemia (e.g., peaked T waves, widened QRS complex, PR interval prolongation).
• Assessment of renal function and medications.
• Evaluate for contributing factors such as acidosis or cellular breakdown.

• Acute management depends on the severity and the presence of ECG changes.
• Calcium gluconate to stabilize the myocardial membrane.
• Insulin with glucose, β2 agonists, or sodium bicarbonate to shift potassium into cells.
• Diuretics, cation exchange resins, or dialysis to remove potassium from the body.
• Addressing underlying causes.

• Monitoring potassium levels in at-risk patients.
• Judicious use of medications that impact potassium levels, especially in patients with renal impairment.
• Dietary potassium restriction in patients with chronic kidney disease.