The tourniquet should be put on the arm about four inches above the vein. A blood pressure cuff that is inflated to 40–60 mm Hg also works well.
The warm pack or water bottle should be put on the area before it is disinfected. Nothing more should touch the area after it is disinfected. Do not apply the warm pack or water bottle directly to the skin. Wrap it in a thin towel to prevent burns. If it hurts, it is too hot.
Tell your patient to try visualization and deep breathing. Observe your patient and have them lie down on their back if you think they might faint. This will improve the blood flow to their head. It also reduces their chances of falling and injuring themselves if they do pass out.
The median cubital vein runs between the muscles and may be clearly visible as a blue bulge in the inside of your elbow. If it cannot be seen it can usually be felt. It is also relatively easy to access because the tissue around it prevents it from rolling away from the needle. Avoid drawing blood from a place where your veins divide or join together. Doing so increases risk of bleeding under the skin.
Alcohol is better than iodine because if the iodine gets into the blood it can alter values that the lab may be looking for. If you do use iodine, follow it with a 70% alcohol swab. Allow the disinfectant to dry before inserting the needle. Do not blow on or fan it with your hand as this will contaminate the area.
Anchor the vein by pulling the skin below the vein taut. This will prevent the vein from rolling. Insert the needle in at a 15 to 30 degree angle and then hold it still while collecting blood. Fill the collection tube with blood, following the order of draw as specified by your laboratory. Release the tourniquet after 1 minute and before removing the needle. Leaving the tourniquet on for longer than a minute will affect the concentration of red blood cells, possibly altering the test. Withdrawing the needle while the tourniquet is still on will result in pain.
Move down the forearm looking for the basilic vein or cephalic vein. These veins may also be visible through the skin. Have the patient lower their arm and make a fist to make the veins more obvious. The cephalic vein runs along the radial side of the forearm. The basilic vein runs along the ulnar side. The basilic vein is less frequently used than the cephalic. It is more likely to roll away from the needle than the cephalic vein because it is not held as tightly in place by the tissues around it. If no veins can be accessed, find the metacarpal veins on the back of the hands. They are usually very visible and can be palpated. They should not be used for elderly patients because the skin is not as supple and does not support the veins as well. In addition, the veins themselves become more fragile.
Are near an infection Have scarring Have a healed burn Are on an arm that is on the same side as where the patient had a mastectomy or fistula placed Are bruised Are above an IV line Are on an arm where the patient has a cannula, fistula, or vascular graft
Pull the needle back a little bit without removing it from the skin. Change the angle of the needle while it is still under the skin so that it can be inserted into the vein.
