Winged Infusion Set

Winged infusion sets "butterfly infusion set", "scalp vein infusion set", "heparin lock" (frequently known under their Terumo Surflo Winged Infusion Set trademark as Butterfly needles) are used in venipuncture (phlebotomy). They are often used with people who have spasticity, or thin, "rolling" blood vessels difficult to access.

Since the winged needle uses a flexible tube, there is less chance of the patient breaking the needle if they move during the procedure. Winged needles are usually a 21g green label, a 23g blue label, and a 25g orange label (however this needle is only used in pediatrics or extreme cases as it is so small that it can often result in hemolyzing the blood sample, thereby invalidating the test), with two plastic 'wings' on either side, flexible tubing, and another needle, generally sheathed with some sort of rubber like material at the other end. This needle, unlike the exposed side, is not sharp. The newer needles produced now also come with a slide and lock safety device that is slid over the needle when it is done being used. This helps prevent accidental sticking with a dirty needle, as well as from accidentally being reused. The phlebotomist attaches a hub or a syringe to the end of the set that has the sheathed needle. This is the same type of hub used for a routine venipuncture. The needle is held by the 'wings' and placed into the vein, generally at a fairly shallow angle. The wings allow the phlebotomist to grasp the needle very close to the end, to ensure accuracy. When the needle is successfully placed into the vein, a 'flash' can be seen. The 'flash' is a small amount of blood that flows into the tubing when the needle enters a vein. The phlebotomist can then push vacuum tubes into the hub and draw blood as usual.

Winged needles are most commonly used when available veins are very small, fragile, or when they are in a place that would make using a normal evacuated tube system difficult. Winged needles are also used on very shallow veins, because the design allows the needle to be inserted at a much more shallow angle than an evacuated tube system allows. Winged needles are nearly always used when drawing blood from the hand, wrist, or other places on the body where veins are very close to the skin.