SPECIMEN COLLECTION AND CONSIDERATIONS

the act of obtaining a blood sample from a vein using a needle to a syringe or a stoppered evacuated tube; it is the most common way to collect blood specimens

The major veins for venipuncture are in the:

Located near the center of the antecubital fossa; preferred vein because it is typically large, closer to the surface and the most stationary; least likely to bruise

Second-choice vein; often harder to palpate than median cubital vein; fairly well-anchored; often the only vein felt in obese patients

Last choice/least preferred; not well-anchored and rolls easily; increased risk of puncturing a median cutaneous nerve branch or the brachial artery; not recommended unless no other vein in either arm is more prominent

Types of blood specimens:

Normally a clear, pale yellow fluid; separated from clotted blood by centrifugation (approx. 10 minutes at an RCF of 1,000 to 2,000g)

Normally a clear to slightly hazy, pale yellow fluid; separates from the cells when blood in an anticoagulant tube is centrifuged; contains fibrinogen

Contains both cells and plasma; must be collected in an anticoagulant tube to keep it from clotting; used for most hematology tests and many point-of-care tests (POCTs), especially in acute care and stat situations

Methods of venipuncture:

preferred method because blood is collected directly from the vein into a tube, minimizing the risk of specimen contamination and exposure to the blood

Discouraged by CLSI due to safety and specimen quality issues; sometimes used on small, fragile, or damaged veins

Can be used with the ETS or a syringe; often used to draw blood from infants and children, hand veins, and in other difficult-draw situations

Venipuncture equipment that restricts venous flow but not arterial flow:

Tourniquet rule:

Tourniquet dimensions:

considered standard needle gauge (adult) for routine venipuncture:

Three basic components of ETS:

usual needle gauge for butterfly system

A handheld medical device that helps medical staff visualize veins before phlebotomy. The device emits infrared light and is held about 7 inches over the potential phlebotomy site

Order of Draw:

Lengths of lancet should be:

Sites for capillary puncture:

Capillary order of draw (CLSI)