LEARNING OBJECTIVE: Identify the correct steps to perform blood collection by the finger puncture method and venipuncture method, and recall Standard Precautions and other safety precautions that apply to blood collection.
There are two principal methods of obtaining blood specimens: the finger puncture method and the venipuncture method. For most clinical laboratory tests requiring a blood specimen, venous blood obtained by venipuncture is preferred. Blood collected by venipuncture is less likely to become contaminated, and the volume of blood collected is greater. Infection control practices, equipment requirements, and step-by-step instructions on performing both of these blood collection methods will be discussed in the following sections.
Under the concept of “Standard Precautions” outlined by the Centers For Disease Control and Prevention (CDC), blood and other bodily fluids should be considered as potentially infectious. To protect medical personnel from direct contact with blood during phlebotomy (blood collection), gloves are required to be worn. Gloves should be disposed of after each patient.
Needles and sharps used in the blood collection process should be handled with extreme caution and disposed of in biohazard sharps containers. Sharps containers should be conveniently located near phlebotomy work sites.
Absorbent materials, such as cotton 2 x 2’s used to cover blood extraction sites, normally contain only a small amount of blood and can be disposed of as general waste. However, if a large amount of blood is absorbed, the absorbent material should be placed in a biohazard waste container and treated as infectious waste.
Clean phlebotomy work site equipment and furniture daily with a disinfectant.
The finger puncture method is used when a patient is burned severely or is bandaged so that the veins are either covered or inaccessible. Finger puncture is also used when only a small amount of blood is needed.
Materials Required for Finger Puncture Procedure
To perform a finger puncture, the following materials are required:
Arrange your equipment in an orderly manner and have it within easy reach. Also, wash your hands before and after each procedure.
Finger Puncture Procedure
To perform a finger puncture, follow the steps given below.
Figure 7-3.—Finger puncture.
When dealing with infants and very small children, the heel or great toe puncture is the best method to obtain a blood specimen. This method is performed in much the same way.
VENIPUNCTURE (VACUTAINER METHOD)
The collection of blood from veins is called venipuncture. For the convenience of technician and patient, arm veins are best for obtaining a blood sample. If arm veins cannot be used due to interference from bandage or IV therapy, thrombosed or hardened veins, etc., consult your supervisor for instructions on the use of hand or foot veins.
Materials Required for Venipuncture Procedure
To perform a venipuncture, the following materials are required:
Arrange your equipment in an orderly manner and have it within easy reach. Also, wash your hands before the procedure.
Position the patient so that the vein is easily accessible and you are able to perform the venipuncture in a comfortable position. Always have the patient either lying in bed or sitting in a chair with the arm propped up.
Never perform a venipuncture with the patient standing up. If patients should faint, they could seriously injure themselves. Also, safeguards should be in place to prevent patients from falling forward when they are seated.
To perform venipuncture, follow these steps:
After cleaning the puncture site, only the sterile needle should be allowed to touch it.