-A process by which blood is obtained from a

patient’s vein

- Venous blood is the deoxygenated blood with a

dark red color

Sites: Antecubital fossa region, wrist,dorsal aspects of hands, veins on the ankle

a. Median cubital- best site for venipuncture ; largest and the best anchored vein

b. Cephalic vein- second choice; superficial vein of arm ( thumb side) commonly

used for venipuncture

c. Basilic vein- should not be chosen, unless no other vein is more prominent due

to its close proximity to the brachiel artery; large vein on inner side

( “pinky side”) of arm 

Note:

• If petechiae appear- it indicates that minute amounts of blood

have escaped into the skin epithelium

• Venous blood is not the specimen of choice for Blood gas

measurement