Venipuncture

Venipuncture is a medical procedure in which a vein is punctured with a needle to obtain a blood sample or to establish intravenous access for the administration of medications or fluids. It is most commonly performed on veins in the upper arm, such as the median cubital vein in the antecubital fossa, though other sites may be used when necessary. The procedure is typically carried out by trained personnel using sterile technique and standard precautions to minimize infection and needlestick injuries.

Common equipment includes a sterile needle or winged infusion set, evacuated collection tubes, a tourniquet, antiseptic solutions, gloves, gauze or cotton, and an adhesive bandage. All sharps and contaminated materials are disposed of in appropriate containers. Proper vein selection, vein stabilization, and patient comfort are important aspects of technique.

The procedure generally involves verifying the test or treatment order, obtaining informed consent, positioning the patient, applying a tourniquet, palpating and selecting a suitable vein, cleansing the site, inserting the needle at a shallow angle with the bevel up, drawing the required blood into tubes, releasing the tourniquet, removing the needle, applying pressure to the site, and labeling specimens for transport to the laboratory.

Common complications are temporary pain, bruising (hematoma), infection, vasovagal syncope, or inadvertent puncture of a nearby structure. Risks are reduced through proper training, aseptic technique, correct needle handling, and appropriate site selection. Alternatives include capillary sampling or the use of venous access devices when venipuncture is not feasible.