Which of the following is used to stabilize a patient's arm during a venipuncture?

Choice A reason:
The light green tube typically contains lithium heparin and is used for plasma determinations in chemistry. It is not suitable for coagulation studies, such as PT, because heparin is an anticoagulant that would interfere with the test results.

Choice B reason:
The lavender tube contains EDTA, which is an anticoagulant that binds calcium. While it is commonly used for complete blood counts (CBC) and other hematology tests, it is not appropriate for coagulation studies because the binding of calcium would affect the clotting process required for a PT test.

Choice C reason:
The royal blue tube can come with different additives or be additive-free, depending on the color of the closure. It is primarily used for trace element testing, toxicology, and nutrient determinations. The additives in a royal blue tube could potentially contaminate the sample and interfere with the PT test.

Choice D reason:
The light blue tube contains sodium citrate, which is the appropriate anticoagulant for coagulation studies like PT. Sodium citrate works by binding calcium in the blood, preventing clotting. The PT test measures the time it takes for a clot to form after re-calcification, making the light blue tube the correct choice for this test.

Choice A Reason:
Wrapping the site with a heel warmer for 30 minutes is a preparatory step before the heel stick procedure. It is used to increase blood flow to the area to make the collection easier. However, it is not the action to take after the blood has been collected. The heel warmer should be removed before performing the heel stick.

Choice B Reason:
Wiping away the first drop of blood is the correct procedure. The initial drop may be contaminated with tissue fluids or alcohol if the site was cleaned prior to the stick, which can affect the accuracy of the test results. Therefore, the first drop should be wiped away, and subsequent blood should be used for the PKU test.

Choice C Reason:
Keeping a pressure dressing on the site for the entire day is not necessary and is not part of the standard heel stick procedure. After the blood is collected, a small bandage is typically applied to stop any bleeding. The site should be monitored for a short time for any signs of continued bleeding or bruising, but a pressure dressing for the day is excessive.

Choice D Reason:
Targeting the central arch area of the foot for the heel stick is incorrect and can be harmful. The recommended area for a heel stick is the lateral portions of the heel to minimize discomfort and avoid injury to the bone or nerves. The central arch area should be avoided to prevent potential harm.