Which specimen needs to be drawn without stasis?

The specimen that needs to be drawn without stasis is lactic acid. This is important because lactic acid levels can be significantly influenced by stasis, which can lead to false elevation of the lactic acid concentration in the blood. When blood flow is restricted, as in the case of stasis, muscles may not receive enough oxygen, leading to an increase in lactic acid production. Therefore, to obtain an accurate measurement of lactic acid levels, it is critical to collect the blood sample without any form of stasis, ensuring that the blood reflects the true physiological state at the time of drawing.

In the case of the other options—glucose, cholesterol, and bilirubin—while proper techniques are still essential, these specimens do not have the same strict requirement regarding stasis as lactic acid does. For glucose testing, stasis may not significantly alter results, although it is always best practice to minimize it. Cholesterol levels typically remain stable despite stasis, and bilirubin can degrade rapidly when exposed to light but is not affected by stasis in the same way as lactic acid. Thus, the unique requirement of drawing lactic acid without stasis sets it apart from these other tests.