A butterfly needle is a device used to draw blood from […]
A butterfly needle is a device used to draw blood from a vein or deliver intravenous (IV) therapy to a vein. Also called a winged infusion set or scalp vein set, a butterfly needle consists of a very thin hypodermic needle, two flexible "wings," a flexible transparent tubing, and a connector.
The connector can be attached to a vacuum tube or collection bag to draw blood or to tubing from an infusion pump or IV bag to deliver fluids or medications. Medications can also be delivered directly to the connector via a syringe.
Butterfly needles offer certain advantages over straight needles. For instance, they allow for more precise placement, particularly in hard-to-access veins. They aren't the best option in every case, however.