A butterfly needle, formally known as a winged infusion set, is a specialized medical device used to access a superficial vein for short-term purposes. These purposes include drawing blood samples or administering intravenous fluids and medications. The design features a small, thin needle attached to flexible plastic tubing and two plastic “wings” that enhance grip and control during the venipuncture procedure. The winged design makes the device suitable for patients with challenging venous access, such as children, older adults with fragile veins, or individuals whose veins are small or tend to roll. This guide provides information on the proper technique for insertion.
Preparation and Site Selection
The procedure begins with gathering all necessary supplies, which include the butterfly needle set, a tourniquet, antiseptic wipes, appropriate collection tubes or a syringe, gauze, medical tape or a transparent dressing, and a designated sharps container. Before touching the patient, stringent hygiene practices must be observed. Hands should be thoroughly washed, and clean gloves must be worn to prevent the introduction of pathogens.
The patient should be positioned comfortably with the extremity, typically the arm, fully supported and extended to stabilize the intended insertion site. A vein assessment is performed by applying the tourniquet approximately three to four inches above the chosen venipuncture area. This action engorges the veins, making them more visible and palpable. The ideal vein is straight, easily seen or felt, and avoids areas of bruising, scarring, or previous puncture attempts, often located on the back of the hand or the forearm.
Once a target vein is selected, the site must be meticulously cleaned using an antiseptic solution, such as an alcohol wipe or chlorhexidine. Clean the area moving in a circular motion outward from the center of the puncture site. It is important that the antiseptic is allowed to completely air-dry according to the manufacturer’s instructions. Failure to do so can cause a stinging sensation for the patient or contaminate the blood sample. The tourniquet should remain in place only temporarily to prevent potential complications like hemoconcentration.
Executing the Insertion
With the site prepared and the needle unit connected to the appropriate collection hub or syringe, the technician holds the butterfly set by pinching the flexible wings between the thumb and forefinger, with the needle’s bevel facing upward. Before inserting the needle, the skin must be anchored by pulling it taut with the non-dominant hand, directly below the insertion site. This anchoring helps to stabilize the vein and prevent it from rolling away from the needle tip.
The needle is then approached at a very shallow angle, typically between 10 and 15 degrees, keeping the trajectory parallel to the vein’s path. A smooth, deliberate motion is used to penetrate the skin and enter the vein. The shallow angle is a deliberate technique to reach the superficial vein without passing completely through the vessel wall. Correct placement is confirmed by the appearance of a “flashback,” which is a small trickle of blood visible in the clear tubing immediately connected to the needle.
Upon confirmation of the blood flash, the needle is advanced minimally to ensure the entire bevel is fully within the vessel lumen. The wings are then laid flat against the skin, and the blood collection or infusion process can begin by engaging the collection device or connecting the IV line. Many modern winged infusion sets feature a mechanism that allows the needle to be secured or retracted immediately after use, which is a safety feature to prevent accidental needlestick injuries.
Securing the Device and Monitoring
Immediately after successful insertion and confirmation of blood flow, the tourniquet must be released to restore normal circulation and prevent unnecessary pressure on the vein. Proper stabilization is then required to prevent the needle from moving or being accidentally dislodged, which could damage the vessel or interrupt the procedure. The wings of the butterfly set are secured flat against the skin using a piece of medical tape placed directly over them.
The flexible tubing is then looped and secured with a second piece of tape or a transparent semipermeable dressing. Ensure that the tape does not cover the connection point to allow for easy access if tubes need to be changed. This method minimizes tension on the needle itself, reducing the risk of accidental removal during patient movement.
While the device is in use, the site must be continuously monitored for signs of complications. Monitoring involves observing the area for signs like infiltration, which presents as localized swelling, coolness, or pallor if the fluid leaks out of the vein into the surrounding tissue. The site should also be checked for hematoma formation, indicated by a rapidly developing bruise around the puncture site, or patient discomfort beyond the initial stick. Prompt recognition of these signs is necessary to ensure patient safety and prevent further tissue damage.
Proper Removal and Disposal
When the procedure is complete, the needle must be removed swiftly and safely to minimize trauma to the vein wall. Preparation for removal involves placing a clean gauze pad gently over the insertion site without applying pressure directly to the needle. The needle is then withdrawn in one quick, smooth motion, pulling backward along the same shallow angle of insertion.
As the needle clears the skin, immediate, firm pressure must be applied to the puncture site with the gauze pad to stop bleeding and encourage clot formation. Maintain the pressure for a minimum of 30 to 60 seconds, or longer if the patient is on anticoagulant therapy. Following removal, the safety mechanism on the butterfly set must be activated immediately. This typically involves a button or lever that retracts or shields the sharp needle tip.
The entire used unit, including the needle, wings, and attached tubing, must be disposed of as a single unit without recapping the needle. The device is immediately placed into a rigid, puncture-proof sharps container designed for the disposal of contaminated biohazard materials. This final step is paramount in preventing accidental needlestick injuries to healthcare personnel.