Which laboratory result is typically not affected by sample hemolysis?

Which laboratory result is typically not affected by sample hemolysis?

• A. Sodium
• B. Potassium
• C. Creatinine
• D. Glucose

Answer: (A)

Hemolysis releases the contents of red blood cells into the serum or plasma, so many analytes are distorted because the intracellular components mix with the extracellular fluid. Sodium is not affected in the same way because it is predominantly an extracellular ion and red blood cells contain relatively little sodium compared with plasma. The measurement of sodium reflects the extracellular sodium concentration, which remains essentially unchanged even when some hemolysis occurs. In contrast, potassium is released in large amounts from ruptured red cells, so hemolyzed samples show spuriously high potassium. Glucose can be decreased because red blood cells continue glycolysis after collection, consuming glucose if the sample isn’t processed promptly or preserved, and some glucose assays can be affected by free hemoglobin. Creatinine measurements can also be unreliable in hemolyzed samples due to interference with some assay methods. Thus sodium is the one typically not affected by sample hemolysis.

Hemolysis releases the contents of red blood cells into the serum or plasma, so many analytes are distorted because the intracellular components mix with the extracellular fluid. Sodium is not affected in the same way because it is predominantly an extracellular ion and red blood cells contain relatively little sodium compared with plasma. The measurement of sodium reflects the extracellular sodium concentration, which remains essentially unchanged even when some hemolysis occurs.

In contrast, potassium is released in large amounts from ruptured red cells, so hemolyzed samples show spuriously high potassium. Glucose can be decreased because red blood cells continue glycolysis after collection, consuming glucose if the sample isn’t processed promptly or preserved, and some glucose assays can be affected by free hemoglobin. Creatinine measurements can also be unreliable in hemolyzed samples due to interference with some assay methods.

Thus sodium is the one typically not affected by sample hemolysis.