71. A phlebotomist needs to collect a PT from a patient with a difficult vein. Which of the following is the best tube for the draw?
Answer: D
Light blue is the best tube for collecting a PT from a patient with a difficult vein.
The light blue tube is specifically designed for coagulation tests, including Prothrombin Time (PT). Its optimal design and additive are suited for ensuring accurate results, making it the best choice for this scenario.
A) Light green
The light green tube is typically used for plasma determinations in chemistry tests and contains lithium heparin as an anticoagulant. While it is useful for other tests, it is not suitable for PT testing, which requires a specific balance of anticoagulant to prevent erroneous results.
B) Lavender
The lavender tube contains EDTA, an anticoagulant that is primarily used for hematology tests such as complete blood counts. Using this tube for PT could lead to inaccurate results due to the different requirements for coagulation tests, thus making it an incorrect choice.
C) Royal blue
Royal blue tubes are used for trace element testing and do not contain any additives or anticoagulants that are appropriate for coagulation studies. Therefore, selecting this tube for a PT would not yield valid results and would be inappropriate for the task at hand.
D) Light blue
The light blue tube is the optimal choice for collecting PT samples as it contains sodium citrate, which is the required anticoagulant for coagulation tests. This ensures that the blood sample is properly preserved for accurate testing, making it the most suitable option for a patient with a difficult vein.
Conclusion
In conclusion, the light blue tube is definitively the correct choice for collecting PT samples due to its specific anticoagulant properties that are essential for coagulation testing. The other options, while useful for different purposes, do not meet the requirements for accurate PT testing and would compromise the quality of the results.