Venepuncture, also known as venupuncture, is defined as the collection of blood from a vein, usually at the anticubital site on an arm, according to MedlinePlus, a website by the U.S. National Library of Medicine and National Institutes of Health. The procedure is most often performed by health-care professionals to collect a sample of a patient's blood for testing. Health-care professionals who need to perform venepuncture should thoroughly familiarise themselves with the procedure before attempting it on a patient. The "Phlebotomy Technician Specialist" textbook by Kathryn A. Kalanick describes the entire protocol for venepuncture.
The first part of successfully performing venepuncture is to ensure that you have all of your equipment prepared before you commence. The procedure requires a sterile needle, sterile syringe or Vacutainer system, tourniquet, cotton wool, antiseptic swab, sharps bin and sticking plaster or tape.
Finding a Vein
The tourniquet is applied just above the elbow and just tight enough to prevent you from inserting a finger underneath. Tourniquets should not be applied for more than about one minute at a time and should not be applied over an open wound. Once the tourniquet is on, it should restrict venous return sufficiently to allow identification of a suitable vein from which to extract the blood sample. The tips of the index and middle fingers can be used to palpate the area to locate a vein. You may need to ask the patient to make a fist to make the vein more prominent.
Preparing the Area
Preparation of the area on and around the located vein involves thoroughly cleansing and sterilising it with an alcohol or povidone-iodine swab, cleaning from the centre toward the periphery. Once cleansed, the site isn't touched. The dominant hand holds the syringe, resting on the fingertips with thumb on top. It's important to ensure that the syringe works. Then you can use the thumb of your free hand to draw the skin below the venepuncture site toward you. This allows you to keep the vein taut and is particularly important with older patients.
The bevel, or sloped opening, of the needle needs to be placed so that it faces upward. The patient should be warned that he will feel a sharp scratch or sharp prick. The needle must be inserted through the skin and into the vein at an angle of about 30 degrees to prevent tearing of the blood vessel. Entry should be halted once the pressure can be felt to give way. This indicates that the lumen of the vessel has been reached. It should be possible at this point to see blood enter the tip of the syringe if the needle was placed correctly. The hand free from holding the needle should be used to draw back on the syringe or to place the Vacutainer tubes into the system.
Finishing the Procedure
After the blood is drawn, the tourniquet is released. The needle should be withdrawn and a cotton wall ball placed immediately on the site. A small amount of pressure may need to be applied to stop bleeding. The sample drawn may be emptied into sample tubes. The needle must be disposed of immediately in the sharps bin. Samples are labelled at the bedside with the correct patient details. Tape or a small sticking plaster is used to secure the cotton wool in place for at least 30 minutes after the procedure.
Many patients find the process of venepuncture quite traumatic. Lippincott Williams and Wilkins' textbook "Nursing Procedures and Protocols" suggests that this problem may be alleviated by reducing the pain the patient feels while undergoing the procedure. Transdermal anaesthesia cream containing lidocaine and prilocaine, such as EMLA Cream, may be applied to clean, dry skin to provide local anaesthesia over the site of venepuncture about 60 minutes prior to the procedure. The anesthetic lasts up to three hours.