Scalp Vein Catheterization

Anatomy and Physiology

Veins are crucial in returning deoxygenated blood to the heart within the circulatory system. Peripheral veins, positioned close to the skin's surface, offer convenient access to the circulatory system; scalp veins, with their superficial location and easy visibility, provide accessibility for catheterization. The primary veins targeted for scalp vein catheterization for peripheral IV access are the posterior auricular, superficial temporal, and frontal veins (eg, supratrochlear and supraorbital) (see Image. Scalp Veins Used for Catheterization and Image. Veins of the Scalp).[2] 

Supratrochlear and Supraorbital Veins

These veins are collectively known as the frontal veins. The supratrochlear vein originates on the forehead, draining the superficial muscles and skin of the forehead and the front of the scalp, areas supplied by the supratrochlear artery. This vein then flows into the angular vein.

Similarly, the supraorbital vein begins on the forehead, anastomosing with the frontal branch of the superficial temporal vein to drain the forehead, eyebrow, and upper eyelid—regions supplied by the supraorbital artery. This vein travels caudally over the frontal bone and superficially to the frontalis muscle before splitting to join the supratrochlear vein inferiorly and the superior ophthalmic vein medially.

Superficial Temporal Vein

The superficial temporal vein has frontal and parietal branches, which drain the superficial muscles and skin of the temporal region. This vein originates from a venous plexus on the side of the head, travels laterally from the temporal region over the zygomatic arch, and enters the parotid gland to become the retromandibular vein, which joins the transverse facial vein.

Posterior Auricular and Occipital Veins

The posterior auricular vein helps drain the muscles and skin of the scalp. Originating from small vessels behind the ear superficial to the temporal fascia, it anastomoses with the occipital vein superiorly. Running just behind the ear, it then confluences with the occipital and deep cervical veins, receiving blood from the posterior branch of the retromandibular vein before turning into the external jugular vein.

Small vessels on the posterior aspect of the scalp give rise to the occipital vein, draining the occipital region's superficial muscles and skin. This vein lies superficial to the occipital fascia and the occipital artery, anastomosing laterally with the parietal branch of the superficial temporal vein and inferolaterally with the posterior auricular vein. The vein then joins the inferior portion of the posterior auricular vein, where it transitions into the external jugular vein.[3]

Indications

Like other peripheral IV catheterizations, a catheterization of a scalp vein can provide blood samples for laboratory analysis and offers direct access to the circulatory system for infusing IV fluids, blood products, or medications. Typically, extremities are the primary sites explored for peripheral IV catheterization. The following are the typical indications for scalp vein catheterization:

• Young patients who need IV administration when peripheral access in the extremities is impossible [4]
• Patients lacking limbs (eg, phocomelia) or facing difficulties obtaining peripheral IV access in the arms or legs
• Smaller caliber catheters in short-term (≤72 hours) access scenarios [4] 
• Endovascular treatment of arteriovenous malformations involving the scalp [5]

Contraindications

Relative contraindications for scalp vein catheterization include:

• Overlying skin infections
• Thrombophlebitis at the catheterization site

Careful attention should be paid to patient discomfort, whether related to the catheterization process or the continuous presence of hardware maintaining the catheter position, as well as potential sensory or motor deficits around the chosen site. As with any superficial vein catheterization procedure, a thorough consideration of risks and benefits is essential. Despite these considerations, peripheral IV catheterization remains crucial for emergent and life-saving access to administer medications, fluids, and blood products, prioritizing clinical urgency in emergency settings.

Equipment

For scalp vein catheterization, the following equipment is required:

• Gauze
• Gloves
• Hair clippers
• Chlorhexidine or alcohol swabs 
• An elastic constricting tourniquet of thin caliber (eg, a rubber band)
• An appropriately gauged IV catheter [4]
  • Choose the smallest catheter available (23g, 25g, or 27g butterfly or scalp vein set) in the shortest length (typically 0.75 inches)
  • 24g catheter-over-needle may also be used but needs additional tubing
• Transparent film dressing
• Tape
• Syringe (for blood collection as necessary)
• Saline flush
• IV tubing
• Tubing extension set
• Saline lock

Personnel

Scalp vein catheterization requires the expertise of an individual authorized and experienced in IV catheterization, given that scalp veins are not typically the primary access site. When exploring scalp veins for peripheral IV access, urgency often underscores the need for successful catheterization, making it advisable to utilize personnel with extensive experience. Generally, a technician, medic, nurse, or clinician is qualified to perform the procedure. In pediatric cases, additional trained personnel may be required to stabilize the child, and child life specialists can contribute by offering distraction or developmentally appropriate support.

Preparation

Adherence to universal precautions and aseptic techniques is crucial for all procedures, including scalp vein catheterization. Proper positioning for finding appropriate scalp veins for catheterization in children and adults involves:

• Minimizing neck mobility
• Reducing body movements during IV catheter placement
• Maintaining the head in the proper angle for a straight path to the scalp vein [6] 
• Site selection is the crucial first step before scalp vein catheterization

After eliminating sites that may pose potential contraindications, choosing a visible vein with adequate caliber to accommodate the catheter is imperative. Optimal success is achieved when selecting a vein that follows a relatively straight path, as tortuous veins can complicate the advancement of the catheter. This strategic approach ensures procedural efficiency and minimizes challenges during catheterization.

Rapid superficial vein assessment is intended to provide a comprehensive preprocedural examination of all newborn superficial veins to allow a reasonable choice of the optimal insertion site suited to the individual patient and optimized for the specific type of venous access device. The superficial veins are methodically inspected, both with and without near-infrared technology, and 7 skin locations are explored in the following order:

• Medial malleolus
• Lateral malleolus
• Popliteal fossa
• Back of the hand and wrist
• Antecubital fossa
• Anterior scalp surface
• Posterior scalp surface [7]

Ultrasound guidance, administered by trained personnel, can be crucial for enhancing the success of scalp vein catheterization.

Technique or Treatment

An elastic band around the scalp is recommended. The optimal placement of this band is caudal to the catheterization site, and gentle pressure can be applied manually or with an assistant's help. If using a circumferential band, it should be positioned distal to the catheterization site but superior to the ears and eyes, avoiding compression of these areas. This compressive application aids in vein distension and enhances visualization. Alternatively, gentle pressure may be applied to the vein caudal to the insertion site using the other hand, not holding the needle. Clipping or shaving hair, especially if the site is within the hair, ensures maximal visualization and reduces the risk of visible scars. Following site identification, meticulous skin preparation with alcohol or chlorhexidine is essential, adhering to aseptic protocols for blood culture acquisition. Consistent utilization of aseptic techniques, including gloves, should be maintained throughout the procedure.

Once the site is selected and prepared, unsheath the catheter and align it with the chosen vein. Maintain the bevel of the needle upwards, angled approximately 30° from the skin's surface, and advance it as the needle pierces the skin. Continue advancing toward the vein until blood appears in the chamber, indicating a successful vein puncture. Adjust the catheter's angle to approximately 10° above the skin and advance it into the vein. After ensuring proper catheter placement, retract the needle while maintaining the catheter position, applying distal pressure on the vein to prevent blood leakage.[8]

Consider applying a transparent film dressing over the catheter hub to secure it. Attach a syringe, IV tubing, or other connectors as needed, flush the catheter with saline, and monitor the site for fluid extravasation and appropriate catheter positioning. Place gauze under the catheter hub to prevent scalp compression, and tape it securely. Given the head's shape, location, and movement, consider stabilizing the scalp vein catheter with a plastic medicine cup, cut and taped over the catheter, as an example.

Complications

Most complications from scalp vein catheterization are similar to other peripheral IV access complications and include:

• Pain [9]
• Bleeding, including hematoma [10]
• Local infection
• Occlusion
• Extravasation of fluids or medication
• Phlebitis and thrombophlebitis [11]
• Bloodstream infection
• Penetration of deeper structures or damage to surrounding tissues
• Nerve damage [12]
• Embolism
• Intracranial air
• Epidural space infection
• Introduction of air into the cavernous sinus [13][14]

Clinical Significance

IV catheterization is a crucial, life-preserving procedure necessary for drug and fluid administration. Scalp veins provide a safe and reliable alternative for establishing peripheral IV access, especially in patients without extremities or facing challenges with extremity IV access, as long as more invasive options are not warranted. The insertion of peripherally inserted central catheters through scalp veins is a feasible option, demonstrating complication rates comparable to other sites.[15] In specific cases, administering a single prophylactic dose of vancomycin in infants before line removal can reduce sepsis incidence.[16]

Enhancing Healthcare Team Outcomes

Scalp vein catheterization involves a collaborative effort among various healthcare professionals to ensure patient-centered care, optimize outcomes, prioritize safety, and enhance overall team performance. Physicians, advanced clinicians, nurses, pharmacists, and other healthcare professionals play distinct roles in the procedure. Physicians are responsible for proper patient evaluation, determining the need for catheterization, and overseeing the procedure. Advanced clinicians and nurses are involved in hands-on catheterization, requiring skills in site selection, aseptic technique, catheter insertion, and catheter maintenance. Pharmacists contribute by ensuring appropriate drug administration protocols. Child life specialists may help provide comfort and distraction during the procedure in cases with children. Effective communication between all team members is essential for seamless coordination; this collaborative approach fosters patient safety, improves outcomes, and promotes a patient-centered care environment.