Digital Block

Aka: Digital Block, Digital Nerve Block, Digital Ring Block, Metacarpal Block, Metatarsal Block, Transthecal Digital Block, Subcutaneous Single Injection Digital Nerve Block, One Injection Digital Anesthesia, Wing Block

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II. Indications

  1. Finger Laceration or other finger related procedure
  2. Toe Laceration or other finger related procedure
  3. Toenail Removal (in Ingrown Toenail)

III. Preparation

  1. Document digital Neurologic Exam prior to procedure
  2. Clean and prepare injection site with Betadine

IV. Technique: General

  1. Prepare 27 to 30 gauge 1.25 inch needle
  2. Use 10 cc control syringe
  3. Draw up 1% or 2% Lidocaine without Epinephrine
    1. Use 4 cc for a finger and 6 cc for a toe
    2. Consider using part bupivicaine 0.25%
  4. Precautions
    1. Aspirate before injecting (do not inject into vessel)
    2. Do not use Epinephrine
    3. Inject perineurally and not in the nerve
      1. Withdraw 2 mm if Paresthesias occur (and reinject)
  5. Technique
    1. Follow techniques per specific sites as below
  6. Post-Injection
    1. Consider small penrose drain to digit base post-block
      1. Use only for brief period
    2. Full Anesthesia may require 5-10 minute wait

V. Technique: Great Toe (Three sided block)

  1. Avoid ring block (four sided) due to ischemia risk
  2. Injection sites are just distal to MTP joint
  3. Step 1: Inject lateral edge of toe
    1. Needle perpendicular to toe (straight up and down)
    2. Inject from dorsal to plantar surface
    3. Use 1-2 cc of Anesthetic
  4. Step 2: Inject dorsum of toe
    1. Partially withdraw needle to tip
    2. Redirect needle across dorsal aspect of toe
    3. Inject from lateral to medial aspect of toe dorsum
  5. Step 3: Inject medial toe aspect
    1. Insert needle perpendicular to medial aspect
    2. Enter skin via area anesthesized in step 2
    3. Inject medial aspect of toe with 1-2 cc
    4. Inject from dorsal to plantar surface
  6. Alternative to Step 2
    1. Some recommend injecting plantar aspect instead

VI. Technique: Digital Block for fingers and toes

  1. Finger Web Space Block (preferred)
    1. Insert needle into web space distal to MCP
    2. Angle needle toward dorsal nerve and inject near bone
    3. Partially withdraw needle to tip
    4. Redirect needle toward palmer nerve and inject
    5. Repeat for opposite side of digit
  2. Finger lateral approach (distal to web space)
    1. Distal to web space by 1 cm
    2. Insertion at lateral margin
      1. Midway between palmar and dorsal aspects
    3. Insert needle
      1. Start perpendicular to finger and inject
      2. Redirect and inject angled toward dorsal surface
      3. Redirect and inject angled toward palmar surface
    4. Repeat for medial finger aspect
  3. Finger dorsal approach (distal to web space)
    1. Position
      1. Hand is palm down against the table with fingers abducted
    2. Insertion site
      1. Distal to web space by 1 cm at dorsal finger
      2. Needle entry sites are to either side of finger over the dorsum and directed toward table (palmar aspect)
    3. Insert needle on the lateral side of the finger (perpendicular to the table)
      1. Start perpendicular to table and insert needle into dorsal finger
      2. Inject the dorsal digital nerve
      3. Continue to advance needle toward table into the palmar aspect of the finger
      4. Inject the palmar digital nerve
    4. Repeat for medial finger aspect
  4. Toe Digital Block
    1. Insert needle at toe dorsum distal to MTP
      1. Needle should be directly midline of toe
    2. Angle needle to one side of extensor tendon
      1. Inject from toe dorsum to plantar surface
    3. Partially withdraw needle to tip
    4. Redirect needle toward other side of extensor tendon
      1. Inject from toe dorsum to plantar surface
  5. Ring Block (not recommended)
    1. Risk of digit ischemia
    2. Inject 1-2 cc into both sides of digit at web space
      1. Inject 1-2 cc at lateral digit
      2. Inject 1-2 cc at medial digit
    3. Inject 1 cc across dorsal surface of digit
      1. Insert needle to bone, withdraw 2 mm and inject
    4. Inject 1 cc across plantar surface of toe

VII. Technique: Transthecal Digital Block (One Injection Digital Anesthesia)

  1. Indications
    1. Single injection Digital Nerve Block commonly used by hand surgeons
  2. Materials
    1. Bupivicaine (0.25%) 2-3 cc
    2. Syringe with 27-30 gauge needle (1 to 1.25")
  3. Preparation
    1. Patient rests hand in supinated position
    2. Clean and prepare finger with Topical Antiseptic (e.g. Betadine, Hibiclens)
  4. Insert needle
    1. Insert needle at volar aspect, overlying MCP crease on palmar surface in midline, over the flexor tendon
    2. Angle needle at 45 degrees toward the distal end of the finger (finger tip)
  5. Advance needle (choose one of the following techniques)
    1. Classic technique depth (into tendon sheath)
      1. Advance needle into flexor tendon sheath (withdraw several millimeters if strike bone)
    2. Modified tenchnique depth (superficial to tendon sheath)
      1. Advance needle into skin to a depth deeper than that which would raise a wheal, but more superficial than the flexor tendon sheath
      2. Follow injection (see below) with massage of the deposited bupivicaine into the tendon sheath
      3. Cannon (2010) Emerg Med J 27(7): 533-6 [PubMed]
  6. Injection
    1. Apply volar pressure proximal to injection site
    2. Deposit Anesthetic at or superficial to tendon sheath (depending on technique above)

VIII. Technique: Subcutaneous Single Injection Digital Nerve Block

  1. Indications
    1. Finger Anesthesia to finger volar aspect, and the dorsal aspect of the middle and distal phalanx
    2. Less effective for thumb Anesthesia than other blocks
  2. Materials
    1. Bupivicaine 0.25% or Lidocaine 1-2%: 2-3 cc
    2. Syringe with 27-30 gauge needle (1 to 1.25")
  3. Preparation
    1. Patient rests hand in supinated position
    2. Clean and prepare finger with Topical Antiseptic (e.g. Betadine, Hibiclens)
  4. Insert needle
    1. Insert needle at palmar aspect, near base of finger, just distal to the distal palmar crease (and proximal to the MCP crease)
    2. Needle inserted superficial to the tendon sheath
      1. Withdraw if needle moves with finger flexion (do not inject into tendon)
  5. Injection
    1. Inject into subcutaneous tissue
    2. Patient should massage the area for 5-10 minutes after injection
  6. References
    1. Yiu (2010) Trick of the trade: Single Digital Block, Aliem, accessed 1/8/2022
      1. https://www.aliem.com/trick-of-trade-single-digital-block/
    2. Warrington (2022) Crit Dec Emerg Med 36(1): 20
    3. Cannon (2010) Emerg Med J 27(7): 533-6 +PMID: 20360491 [PubMed]

IX. Technique: Wing Block

  1. Indications
    1. Paronychia Incision and Drainage
  2. Materials
    1. Lidocaine 1% or 2%: 3 cc
    2. Syringe with 30 gauge needle 1"
  3. Preparation
    1. Patient rests hand in pronated position (palm resting against table)
    2. Clean and prepare finger with Topical Antiseptic (e.g. Betadine, Hibiclens)
  4. Landmarks
    1. Intersection of proximal nail fold and lateral nail folds
    2. Needle insertion point is 3 mm proximal to proximal nail fold and 3 mm lateral to lateral nail fold
  5. Injection
    1. Injection 1: Transverse, parallel to proximal nail fold
      1. Direct needle 45 degrees off skin plane
      2. Inject along a line parallel and proximal to proximal nail fold
    2. Injection 2: Longitudinal toward finger tip, parallel to lateral nail fold
      1. Withdraw needle and reinsert, directing needle 45 degrees off skin plane toward finger tip
      2. Inject along a line parallel and lateral to lateral nail fold
    3. Injection 3: Longitudinal toward finger tip (optional), parallel to lateral nail fold
      1. Withdraw needle and reinsert, directing needle 45 degrees off skin plane toward finger tip
      2. Inject along a line parallel and lateral to lateral nail fold on other side
  6. Resources
    1. YouTube Video (Dr. Leggit)
      1. https://www.youtube.com/watch?v=47qHTmEEHdg
    2. Emedicine Medscape
      1. http://emedicine.medscape.com/article/80887-technique#c6
  7. References
    1. Leggit (2017) Am Fam Physician 96(1): 44-51 [PubMed]

X. References

  1. Arora and Menchine in Herbert (2013) EM:Rap 13(12): 11
  2. Mandracchia (July, 1998) Hospital Medicine, p. 36-43
  3. Mortiere (1996) Wound Management, PFP Printing, p.31-3
  4. Moy in Pfenninger (1994) Procedures, Mosby, p. 148-9
  5. Latham (2014) Am Fam Physician 89(12): 956-62 [PubMed]

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