High blood potassium

High blood potassium, also known as hyperkalemia, is a condition characterized by an elevated level of potassium in the blood. Potassium is a critical electrolyte necessary for the proper functioning of nerve and muscle cells, including those in the heart. Normal blood potassium levels are typically between 3.5 and 5.0 millimoles per liter (mmol/L). Levels above 5.5 mmol/L are generally considered to be hyperkalemic.

Causes

Hyperkalemia can result from a variety of causes, which can be broadly categorized into issues related to increased intake, decreased excretion, or movement of potassium out of cells. Common causes include:

• Chronic kidney disease (CKD): Impaired kidney function can reduce the ability to excrete potassium, leading to accumulation in the blood.
• Medications: Some drugs, such as ACE inhibitors, potassium-sparing diuretics, and non-steroidal anti-inflammatory drugs (NSAIDs), can increase potassium levels.
• Adrenal insufficiency: Conditions like Addison's disease can impair hormone production, affecting potassium regulation.
• Cellular destruction: Trauma, burns, or conditions such as rhabdomyolysis or hemolysis can release potassium from inside cells into the bloodstream.
• Excessive intake: Although rare, consuming large amounts of potassium through diet or supplements can contribute to hyperkalemia, especially in people with compromised kidney function.

Symptoms

Symptoms of hyperkalemia can vary depending on the severity of the condition. Mild cases may be asymptomatic, while severe hyperkalemia can be life-threatening. Symptoms may include:

• Muscle weakness
• Fatigue
• Nausea
• Paralysis
• Arrhythmias (irregular heartbeats)
• Cardiac arrest in extreme cases

Diagnosis

Diagnosis of hyperkalemia involves a combination of clinical evaluation and laboratory tests. Key diagnostic steps include:

• Blood tests: Measurement of serum potassium levels is the primary test for hyperkalemia.
• Electrocardiogram (ECG): An ECG can show characteristic changes associated with high potassium levels, such as peaked T waves, widened QRS complexes, and potentially life-threatening arrhythmias.

Treatment

Treatment for hyperkalemia depends on the severity and underlying cause. Approaches may include:

• Dietary restrictions: Limiting intake of potassium-rich foods.
• Medications: Drugs that increase potassium excretion (e.g., loop diuretics) or stabilize the heart's electrical activity.
• Renal replacement therapy: In cases of severe kidney dysfunction, dialysis may be necessary to remove excess potassium.
• Emergency treatments: In acute cases, treatments such as intravenous calcium, insulin with glucose, or sodium bicarbonate may be used to quickly reduce potassium levels and stabilize heart function.

Prevention

Preventing hyperkalemia involves managing risk factors and conditions that can lead to elevated potassium levels. This includes regular monitoring of potassium levels in people with kidney disease, careful use of medications that affect potassium levels, and dietary modifications for those at risk.