Peripheral Blood and Blood Smear Procedure

What is peripheral blood?

Peripheral blood is the fluid that travels through your heart, arteries, capillaries, and veins. Its most important function is to transport oxygen and other nutrients to your body's cells and tissues, and to remove carbon dioxide and other waste products from the body. Peripheral blood also plays an essential role in the immune system, delivery of hormones, and temperature regulation.

Why is a peripheral blood sample examined?

Taking a blood sample, also known as venipuncture, is a minimally invasive way to gather information about the types of cells circulating throughout the body. The components of the blood may be examined along with the levels of red blood cells, white blood cells, and platelets. The examination of blood is useful in the diagnosis of many conditions, including leukemia, lymphoma and myeloproliferative disorders.

How is a peripheral blood sample taken?

To begin the procedure of drawing a peripheral blood sample, the patient sits or lies in a chair with the arm extended on an armrest. A tourniquet is placed around the upper arm to allow blood to collect in the veins, making the veins easier to find and puncture. The skin is then sanitized, usually the inside of the elbow. A sterile needle is then inserted into a vein, and attached to a collection container, typically a tube. After collection, the needle is removed and a bandage placed on the puncture site. Pressure may be applied for a few minutes to stop the bleeding.

What is done with the peripheral blood sample?

After the blood is drawn, a small amount of the examined sample is dropped and spread along a glass slide to create a blood smear. The blood smear is examined for the number and kinds of cells that are present and other morphologic abnormalities.

Are there any risks of a peripheral blood sample?

Risks include excess bleeding, bruising, fainting or light headedness, and infection. The risk for infection is minimized by the sanitation of the skin and use of a sterile needle.