The superficial veins of the upper extremities of the body are used for venepuncture because they are located beneath the skin.
When selecting the site time must be spent inspecting the area and observing for adjacent structures such as arteries.
Arteries will pulsate when palpated, however, veins will not.
In venepuncture, the antecubital fossa is the most frequently chosen as it is easier to access and enables copious and repeated samples to be taken (Ernst 1995)
The antecubital fossa consists of three veins:
Median Cubital
Best vein for several reason. Most accessible, safest, stable, closest to the surface of the skin and less sensitive. Care must be taken to avoid the brachial artery, which is identified by its pulse.
Cephalic
Second best option (thumb side of the wrist) usually for more challenging patients like the elderly due to skin elasticity and subcutaneous fat around the vessel.
Basilic
Serves as a last resort for blood draws. It is not as close to the skin surface as the median cubital and cephalic veins, which poses a greater risk of damage to the median nerve and brachial artery.
