Rejection of hemolyzed samples can jeopardize patient safety

Area of Science:

• Clinical Chemistry
• Laboratory Medicine
• Patient Safety

Background:

• In vitro hemolysis is a common reason for laboratory sample rejection.
• Albuterol sulfate, used for asthma, can induce hypokalemia, requiring careful laboratory monitoring.

Observation:

• A pediatric patient receiving albuterol sulfate required laboratory tests, including electrolytes.
• The collected blood sample showed signs of hemolysis and micro-clots, leading to unreported results.
• The laboratory technician was trained to withhold potentially overestimated potassium results from hemolyzed samples.

Findings:

• The hemolyzed sample had 2.3 g/L of free hemoglobin, exceeding the laboratory's 0.9 g/L rejection threshold.
• The initial potassium result was 3.9 mmol/L, while a new sample showed 2.1 mmol/L, indicating a significant discrepancy.
• Withholding the initial potassium result could have masked the patient's hypokalemia.

Implications:

• Laboratories must consider clinical context and patient conditions before discarding results.
• Clear communication between laboratory and clinical staff is vital for accurate diagnosis and patient safety.
• Standard operating procedures should be reviewed to ensure patient well-being is prioritized over sample rejection criteria.