Lesson 4: Specimen handling

getting blood from the body

getting blood from the vein

is the act of obtaining a blood sample from a vein using a needle attached to a syringe or a stoppered evacuated tube.

Collection tubes vary in volume from approximately _ (pediatric) to _ mL adult

most common site for venipuncture

typically made of rubber or Velcro, is applied to the arm to temporarily restrict blood flow and promote vein dilation, facilitating vein identification.

The gauge of the needle is inversely related to the size of the needle; the _ the number, the __ the needle bore and length.

sometimes referred to as a butterfly because of the appearance of the setup, may be used whenever the veins are fragile, small, or hard to reach or find.

The butterfly is attached to a piece of tubing, which is then attached to either a _ or a _. Because of potential needle sticks, this practice may be discouraged.

Avoid sites near _ lines

If both arms have IV lines, draw _ the IV site and discard the first _ mL due to possible contamination with the IV fluid.

involved the use of whole blood, serum, or plasma

Whole blood uses both the liquid portion of the blood called _ and the cellular components (RBCs, WBCs, and platelets). This requires blood collection into a vessel containing an _.

Complete mixing of the blood immediately following venipuncture is necessary to ensure the anticoagulant can adequately inhibit the blood’s clotting factors

If a tube does not contain an anticoagulant, the blood’s clotting factors are active to form a _. ● The clot is encapsulated by the large protein fibrinogen. This fluid is called _.

lacks fibrinogen and has slightly higher potassium than plasma.

Serum should clot for at least _ _ before centrifugation

does not need clotting time, allowing faster turnaround time.

the sample accelerates the process of separating the plasma and cells.

Specimens should be centrifuged for approximately _ at an RCF of _ to _ but should avoid mechanical destruction of red cells that can result in hemoglobin release, called _

used to measure blood gases (O₂, CO₂) and pH

preferred over tubes due to high arterial pressure

The _, _, and _ arteries are common puncture sites