Which of the following is a disadvantage of capillary puncture?

Which of the following is a disadvantage of capillary puncture?

• A. Limited sample amount
• B. Greater risk of hemolysis
• C. Limited lab tests
• D. All of the above

Answer: (D)

Capillary puncture uses only a tiny amount of blood, which directly limits what you can test. The small sample volume means many laboratory panels or repeat tests can’t be performed or require a venous sample instead. Collecting capillary blood also carries a higher risk of hemolysis, especially if the site is squeezed or the sample is mishandled; hemolyzed samples can skew results for several common analytes. Additionally, not all tests are validated for capillary blood or for the volumes obtained; some tests need plasma or serum from venous blood and larger quantities, so the range of reliable lab tests is more limited. For these reasons, all of the listed disadvantages can apply, making “all of the above” the best answer.

Capillary puncture uses only a tiny amount of blood, which directly limits what you can test. The small sample volume means many laboratory panels or repeat tests can’t be performed or require a venous sample instead. Collecting capillary blood also carries a higher risk of hemolysis, especially if the site is squeezed or the sample is mishandled; hemolyzed samples can skew results for several common analytes. Additionally, not all tests are validated for capillary blood or for the volumes obtained; some tests need plasma or serum from venous blood and larger quantities, so the range of reliable lab tests is more limited. For these reasons, all of the listed disadvantages can apply, making “all of the above” the best answer.