From the Guidelines
Hyperkalemia is a true result if the patient has a serum or plasma potassium level greater than 5 mmol/L [ 1 ].
Factors Influencing Result Accuracy
The following factors can influence the accuracy of a high potassium result:
- Recent strenuous exercise
- Hemolysis during blood sampling [ 1 ]
- Certain medications such as angiotensin-converting enzyme inhibitors (e.g., lisinopril) or potassium-sparing diuretics (e.g., spironolactone) [ 1 ]
- Blood sample collection in a tube with a potassium-containing additive, such as EDTA
- Improper handling of the blood sample, resulting in leakage of potassium from red blood cells
Conditions Associated with True Hyperkalemia
A true high potassium result may be expected in patients with:
- Renal insufficiency [ 1 ]
- Chronic kidney disease (CKD) [ 1 ]
- Diabetes [ 1 ]
- Heart failure (HF) [ 1 ]
- Those taking potassium supplements (e.g., potassium chloride) [ 1 ]
From the FDA Drug Label
The administration of oral potassium salts to persons with normal excretory mechanisms for potassium rarely causes serious hyperkalemia. Potassium supplements are contraindicated in patients with hyperkalemia since a further increase in serum potassium concentration in such patients can produce cardiac arrest
Hyperkalemia is a true result, as it can occur due to various conditions, including the administration of potassium supplements, especially in patients with impaired excretory mechanisms or certain medical conditions, such as chronic renal failure or systemic acidosis 2 2.
- Key points:
- Hyperkalemia can be asymptomatic and may be manifested only by an increased serum potassium concentration and characteristic electrocardiographic changes.
- Treatment measures for hyperkalemia include elimination of potassium-containing foods and medications, intravenous calcium gluconate, and correction of acidosis.
From the Research
Hyperkalemia Results
- Hyperkalemia can be a false result due to preanalytical errors, such as hemolysis, which can lead to pseudo-hyperkalemia 3
- Preanalytical errors can be categorized into four groups: patient factors, sample type, blood collection procedure, and tube processing 3
- Hemolysis is a common preanalytical error that can contribute to pseudo-hyperkalemia, and its detection and correction are crucial to prevent inaccurate results 3, 4
- The use of angiotensin-converting enzyme (ACE) inhibitors can increase the risk of hyperkalemia, especially in patients with renal insufficiency or congestive heart failure 5
- Physical exercise can also induce short-term changes in serum potassium concentration, but the effect of ACE inhibitors and statins on serum potassium during exercise is not additive 6
- Dietary factors, such as a high intake of potassium, can also contribute to hyperkalemia, especially in patients taking medications that predispose to hyperkalemia, such as ACE inhibitors and potassium-sparing diuretics 7
Factors Affecting Hyperkalemia Results
- Patient factors, such as high platelet, leukocyte, or erythrocyte counts, can affect potassium results 3
- Sample type and blood collection procedure can also impact potassium results, and inappropriate equipment, patient preparation, and sample contamination can lead to preanalytical errors 3
- Tube processing, including sample transport and storage conditions, can also affect potassium results 3
- Renal function and the use of certain medications, such as ACE inhibitors and potassium-sparing diuretics, can increase the risk of hyperkalemia 5, 7
Detection and Correction of Hyperkalemia
- Detection of preanalytical errors, such as hemolysis, is crucial to prevent inaccurate results, and corrective actions, such as sample re-collection or re-analysis, may be necessary 3, 4
- Laboratories should develop context-specific, evidence-based reporting criteria to minimize reporting of inaccurate results without disrupting delivery of care 4
- Patient education and counseling on dietary factors and medication use can help prevent hyperkalemia 7