Which specimens are drawn with stasis?

• A. Glucose Test (OGTT)
• B. Lactic Acid
• C. CBC
• D. Hematocrit

Answer: (B)

Lactic acid measurements are extremely sensitive to what happens after the blood is drawn. When blood sits in a tube or at the puncture site, the cells continue to metabolize nutrients, and glycolysis can produce more lactate, changing the result. Because of this, lactic acid testing is all about controlling the pre-analytical conditions, including minimizing stasis (the blood sitting and pooling). In practice, this means handling the specimen promptly, cooling it, and processing quickly to prevent artificially high lactate levels.

The other tests listed are not as affected by stasis in the same way. Glucose testing has methods to stabilize glucose and slow glycolysis; CBC and hematocrit rely on cellular components that aren’t as dramatically altered by short delays or pooling as lactate is. Thus, lactic acid is the one most specifically associated with the impact of stasis, making it the best answer in this context.