Topic

• Introduction
• Indications
• Contraindications
• Procedure
• Coding Information

Figure(s)

• Cross Section of a Digit
• Digital Block Technique
• Alternative Technique

• Digital nerve block is commonly performed to provide anesthesia of an entire digit. This technique has the advantage of providing longer duration of anesthesia over local infiltration, and it does not distort anatomic landmarks for digital surgery.
• Administration of 1–3 mL of 2% lidocaine provides adequate anesthesia without use of a large volume. The great toe or thumb can also receive some additional superficial innervation proximally, and a slightly larger volume of solution (administered as a dorsal skin wheal) may be needed for these digits.
• All digital blocks require some time for anesthetic to affect the nerve sheath; many novice and impatient physicians continue to add volume when a few minutes of time would produce the desired effect.
• Increasing rates of vascular compromise can be observed with circumferential infiltration, especially if volumes >7–8 mL are administered to smaller digits. Use of 3- or 5-mL syringes can help avoid temptation to deliver larger volumes. Impaired digital circulation can also occur if an individual has vasospastic disease—e.g., Raynaud's phenomenon—or if the digit is markedly swollen before infiltration.
• Despite evidence for the safety of the practice, it is still advisable to avoid addition of epinephrine to lidocaine for use on digits.
• Historically, physicians were instructed to insert the needle into the web space to perform a digital block. The advantage of web space injection is that the nerve can be injected at the site of bifurcation between the adjoining digits. Blood vessels of the web space are larger than on the digit, and intravascular injection of anesthetic can easily occur with the web space technique. Physicians are encouraged to use digital techniques described herein.

• Repair of digital lacerations
• Nail procedures (e.g., ingrown nail surgery, nailbed biopsy, nail removal)
• Incision and drainage of abscesses (e.g., felon surgery, paronychia surgery)
• Anesthesia for fracture or dislocation manipulation of digital orthopedic injuries
• Tumor or cyst removal or ablation (e.g., digital mucous cysts, giant cell tumors of sheaths, warts)

Contraindications and Precautions

• Use of epinephrine added to lidocaine
• Use of volumes >7 mL, especially in individuals with peripheral vascular disease, Raynaud's disease or phenomenon, digital vasculitis, impaired circulation (e.g., diabetes, scleroderma)

• Cross section of digit reveals nerves traversing laterally on each side of digit (Fig. 29-1). 1 nerve appears to be plantar or palmar, and 1 is more dorsal.
• 1 method of digital block inserts needle laterally into base (proximal portion) of digit, 1 cm distal to web space (Fig. 29-2A). Insert the needle to the bone, and infuse anesthetic. Angle needle volarly and dorsally (Fig. 29-2B). Repeat this technique on the opposite side.
• Alternate technique inserts needle near junction of dorsal and lateral surfaces of digit. Slide needle along lateral surface, injecting as needle tip is withdrawn back to insertion site (Fig. 29-3A). Without pulling needle tip out of skin, redirect needle tip along dorsum of digit and again administer anesthetic as needle is withdrawn (Fig. 29-3B).
• Insert needle near the junction of volar and lateral surfaces of the digit. Administer anesthetic along opposite sides of digit (Fig. 29-3C).

No CPT code exists for digital nerve block. The service is included in reporting for the procedure for which it is performed (e.g., laceration repair, biopsy service).