Case report of unexplained hypocalcaemia in a slightly haemolysed sample

Area of Science:

• Clinical Chemistry
• Laboratory Medicine
• Diagnostic Errors

Background:

• Routine blood tests are common for patients presenting with non-specific symptoms.
• Pre-analytical errors can significantly impact laboratory test results.
• Hemolysis is a frequent complication during sample collection and processing.

Observation:

• A young, healthy adult patient presented with flu-like symptoms.
• Initial blood analysis showed a falsely low calcium level due to sample hemolysis and contamination.
• Urgent repeat investigations revealed normal calcium levels.

Findings:

• The initial abnormal calcium result was a pre-analytical error, not a true clinical finding.
• Sample contamination, compounded by hemolysis, masked the true nature of the error.
• The laboratory's standard flagging system failed to identify the contamination due to the hemolysis complication.

Implications:

• This case underscores the critical need for robust pre-analytical quality control in clinical laboratories.
• Healthcare providers should be aware of potential interferences like hemolysis and contamination.
• Improved protocols are necessary to detect and prevent missed diagnostic errors stemming from sample quality issues.