Erroneous potassium results: preanalytical causes, detection, and corrective actions.

Area of Science:

• Clinical Chemistry
• Laboratory Medicine
• Analytical Biochemistry

Background:

• Potassium levels are critical for patient health, requiring precise laboratory monitoring within a narrow physiological range.
• Inaccurate potassium measurements, often due to preanalytical errors, can lead to incorrect clinical decisions.
• Pseudo-hyperkalemia, pseudo-hypokalemia, and pseudo-normokalemia occur when test results do not reflect the patient's true in-vivo potassium status.

Approach:

• This review systematically analyzes preanalytical factors that can bias potassium measurements.
• Errors are categorized into patient factors, sample type, blood collection procedures, and tube processing.
• Hemolysis is specifically examined as a common cause of pseudo-hyperkalemia.

Key Points:

• Preanalytical errors significantly impact the reliability of potassium test results.
• Factors include high blood cell counts, inappropriate sample collection, contamination, and improper transport/storage.
• Hemolysis is a frequent contributor to falsely elevated potassium levels.

Conclusions:

• Understanding and mitigating preanalytical errors is essential for accurate potassium testing.
• This review provides a framework, including a flowchart and table, for identifying and preventing biased results.
• The findings aim to improve the accuracy of potassium measurements and patient care.