What Is A Scalp Vein Set?

Definition

Scalp vein set, or winged needle, is a sterilized and single-use medical device. Mostly, they are equipped with a butterfly needle connected to flexible tubing. This tubing is provided with a Luer Lock or Luer slip connector at its proximal end, allowing a firm and stable connection with the infusion line.

It is used for blood sampling and quick small infusion solutions, frequently used in treating patients with contractures and in pediatric patients.   It is primarily used for venipuncture, also known as winged infusion or butterfly set.

Parts 

1. Hypodermic needle
2. Two flexible bilateral wings are used mostly, but a single wing is widely used in Chinese hospitals.
3. Flexible small-bore transparent tubing (20-35 cm long)
4. Luer lock/slip connector
5. Plastic cap

Sizes

Generally, butterfly sets are available in 18-27 gauge bore, 21G and 23G being the most popular. 

Bilateral Wings	Grey	Brown	Orange	Violet	Blue	Black	Green	Yellow	Beige
Size	27G	26G	25G	24G	23G	22G	21G	20G	19G

Usually, small-bore scalp vein sets are for children, and adults use big-bore scalp vein sets. It depends on the size of the patient’s veins and medicine. Besides, some kinds of drugs must be infused by big-bore scalp vein sets. 

In phlebotomy, people avoid using 25G and 27G butterflies because they believe that needles with small-bore could damage the blood cells and cause blood samples to clotting. If these happen, they think that the blood test results will be compromised or erroneous. Theoretical calculation and in vitro experiments, however, showed that this was not true. It was found out that the shear stress and destruction of blood cells decreased if the bore of the needles was decreased. To confirm this finding further, a clinical trial using 21G, 23G, and 25G butterflies connected to vacuum tubes revealed the same degree of blood cell destruction and the same coagulation panel test results.

Uses

Generally, scalp vein sets are used in the following indications: 

1. repeated short-term injection or injection of a small volume of drugs or blood derivatives,

2. one-time blood sampling, and

3. difficult or small-diameter veins, such as in infants and children, and normal veins of adults

Specifically, scalp vein sets are used mainly and primarily for venipuncture. This is commonly practiced in different specialties and not confined to a particular specialty. A scalp vein set is frequently used because it is a very cheap and easily available device that can be used in various procedures.

Features and Benefits 

· Butterfly set is designed for long-term infusion.  It is primarily used for venipuncture and intravenous infusions. 

· Flexible elastic extension tubing allows safe injection away from the venous puncture site, reducing the risk of displacement.

· Scalp vein set is designed to provide rapid venous infusion with greater patient comfort.

· Thin wall needle provides a better flow rate per gauge because more circumference is available for better fluid flow.

· Short beveled siliconized needle leads to atraumatic cannulation. Injection needles with high-grade stainless steel and a triple bevel edge guarantee the needle’s atraumatic and painless insertion.

· Butterfly-shaped wings facilitate easy handling and attachment with the skin.

When the vein is punctured to insert the needle, the thumb and index finger hold the Butterfly with its wings. This style of grasping the Butterfly, which is very close to the needle, leads to the needle’s accurate and well-directed placement and facilitates its insertion. The set’s design makes it possible to insert the needle at a shallow angle. When the needle accurately punctures the vein, there is a backflow of the blood in the set’s transparent tubing, signaling and showing that the cannula is inside the vein.

The Butterfly has several advantages over a simple straight needle. With its flexible tubing, it could be attached to more body surfaces and thus tolerate the movements of the patient. Because the Butterfly could be held firmly while inserting, “rolling,” fragile, or inaccessible veins could be accurately punctured.

· Butterfly is attached to a soft, non-toxic, non-irritant, medical-grade tube, which does not kink or coil.

· Provided with flexible Luer fitting.

· Butterflies are color-coded to determine needle size easily.

Scalp Vein Set as Life-saving Device

Critical Use of Scalp Vein Set

Inserting a scalp vein set is an important, sometimes critical, step in the care of sick infants and children. This is so because the scalp vein set provides a direct route for the administration of fluids and medications. If the fluids and medications are not delivered on time, the patient may die!  There are other anatomic sites wherein intravenous (IV) insertions can be done. However, the peripheral sites—the scalp being one—are the most common and most readily available. In this instance, the scalp vein set is the most appropriate device to use.

Advantages of Using Scalp Vein Set

Inserting an IV line into the peripheral vein of a child or infant is very challenging and risky. This is because this age group has peripheral veins that are narrower, have more subcutaneous fat, and their veins easily constricted. They are restless and very uncooperative during the procedure. The scalp veins provide a secondary option for peripheral intravascular access in small children and infants because it has minimal subcutaneous fat, making it easier to see the veins. The head can be readily controlled, thus reducing the infant or child’s unnecessary movements and the absence of a flexible joint; these factors reduce the likelihood of catheter dislodgment, common with IV catheters placed in the arms or legs. In this instance, the scalp vein set is the most appropriate and safest device to use.

Last Resort Use of Scalp Vein Set

Scalp vein set insertion is indicated in any patient who requires intravascular access to administer fluids or medications. The decision to use one of the scalp veins as a scalp vein set insertion site should be based on inspection or palpation of various sites. Although the scalp veins provide certain advantages, the best place to use them is based on the clinician’s assessment of what vein offers the most excellent chance for successful catheterization. Scalp vein set insertion should only resort to scalp vein when no other peripheral veins from the arms and legs can be used.