Phlebotomy is a technique in which a needle is temporarily inserted into a vein to provide venous access for venous blood sampling. [1, 2, 3] Veins have a three-layered wall composed of an internal endothelium surrounded by a thin layer of muscle fibers, which in turn is surrounded by a layer of connective tissue. Show Identification of the optimal site for venous access (see Technical Considerations) involves both visual and tactile evaluation. After applying a venous tourniquet, the physician should inspect and palpate potential sites, starting with the nondominant extremity. On palpation, the vein should be soft and bouncy, it should refill after being depressed, and it ideally should be well supported by the surrounding tissue. Phlebotomy is commonly performed with either an evacuated tube system (eg, Vacutainer; BD, Franklin Lakes, NJ) or a syringe and needle or winged butterfly needle device (see Technique).  Next: IndicationsIndications for phlebotomy include the following:
Previous Next: ContraindicationsContraindications for phlebotomy include the following:
Previous Next: Technical ConsiderationsAnatomyThe superficial veins of the upper extremities, particularly those in the antecubital fossa, are the ones most commonly selected for phlebotomy because they are usually readily visible and easily palpable. The antecubital fossa contains four veins (see the images below). Of these, the median cubital vein is usually the vein of choice for phlebotomy: It is typically more stable (less likely to roll), it lies more superficially, and the skin overlying it is less sensitive than the skin overlying the other veins. View Media Gallery View Media Gallery View Media Gallery In many cases, the metacarpal veins are easily visualized and palpated (see the image below). However, obtaining needle access on the dorsal hand is more painful, and the metacarpal veins are more likely to roll and collapse on vacuum application than the antecubital veins are. View Media Gallery It appears that the device used to collect blood is the strongest independent predictor of hemolysis in blood samples drawn in the emergency department (ED). An ED study suggested that the most effective strategy to reduce the rate of hemolysis in the ED is to use butterfly needles for phlebotomy rather than intravenous catheters. [4] Previous Periprocedure
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of 23 Tables Back to List Contributor Information and Disclosures Author Gil Z Shlamovitz, MD, FACEP Associate Professor of Clinical Emergency Medicine, Keck School of Medicine of the University of Southern California; Chief Medical Information Officer, Keck Medicine of USC Chief Editor Vincent Lopez Rowe, MD Professor of Surgery, Program Director, Integrated Vascular Surgery Residency and Fellowship, Department of Surgery, Division of Vascular Surgery and Endovascular Therapy, Keck School of Medicine of the University of Southern California Acknowledgements Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference What is the first choice of vein?After the needle selection, phlebotomists begin to look and feel for a viable vein. The first attempt is the antecubital fossa area, starting with the median cubital vein, then the cephalic vein, and the basilic vein.
What vein should be selected first for venipuncture?The antecubital area of the arm is usually the first choice for routine venipuncture. This area contains the three vessels primarily used by the phlebotomist to obtain venous blood specimens: the median cubital, the cephalic and the basilic veins.
Which vein is best for blood draw?The median cubital and cephalic veins are preferred for blood sampling, but other arm and hand veins may be used. The cephalic vein is located on the lateral (radial) side of the arm, and the basilic vein is located on the medial (ulnar) side.
What are the 3 main veins to draw blood?Three Primary Veins
There are three veins most commonly used in venipuncture, or phlebotomy. They are the cephalic, median cubital, and basilic veins. These three veins are found in the antecubital area. The cephalic vein is found on the lateral, or outside, of the arm.
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