11. A phlebotomist is performing a venipuncture on a patient who requires a complete blood count (CBC), blood alcohol concentration (BAC), comprehensive metabolic panel (CMP) and a prothrombin time (PT). Which of the following additives must be in the tube that is collected first?
Answer: D
Fluoride must be in the tube that is collected first.
For the collection of a blood alcohol concentration (BAC) test, it is crucial that fluoride is used as an additive in the first tube to prevent glycolysis, which can interfere with the accuracy of the test results.
A) Heparin
Heparin is an anticoagulant used in various tests but is not suitable for a blood alcohol concentration test. Collecting a tube with heparin first could lead to inaccurate results for BAC, making it an incorrect choice for this scenario.
B) EDTA
EDTA is an anticoagulant primarily used for complete blood counts (CBC) and other hematological tests. While it is effective for those tests, it does not prevent glycolysis and is therefore not appropriate for the first tube in this situation.
C) Citrate
Citrate is an anticoagulant used in coagulation studies, such as prothrombin time (PT) tests. However, it does not serve the specific purpose required for preventing glycolysis in blood alcohol testing, making it an unsuitable option for the first tube collected.
D) Fluoride
Fluoride is an additive that inhibits glycolysis, making it essential for collecting blood samples intended for alcohol testing. It is the correct choice for the first tube to ensure the integrity of the BAC results.
Conclusion
Fluoride is the necessary additive for the first tube collected in this scenario, as it prevents the breakdown of glucose and ensures accurate blood alcohol concentration measurements. All other options, including heparin, EDTA, and citrate, fail to provide the necessary preservation for BAC testing and are therefore incorrect choices for the first tube.