Digital Ischemia: Guidance for Administration of OnabotulinumtoxinA (Botox®)

Note: Botox® will be ordered and administered by orthopedic hand surgeon 

Preparation Steps:

• Evaluate need for sedation
• Gather supplies
  • Botox 100 unit vial
  • 0.9% NS (injectable) vial
  • Alcohol swabs
  • 5 cc syringe x 1
  • 18 G needle x 2
  • 1 cc TB syringe x 1
• Dilute vial
  • Add 4 mL NS to 100 unit Botox vial (2.5 units/0.1 mL)
  • Assign a 1 hour expiration to vial

Dosing Recommendations (must be individualized):

• Administer 25 - 55 units per extremity, divided into multiple injections
  • Hand (max of 8 total injections)
    • Up to 4 x 5 unit (0.2 mL) injections to interdigital spaces
    • 2 x 5 unit (0.2 mL) injections to superficial palmar arch
    • 2 x 10 unit (0.4 mL) injections adjacent to radial and ulnar arteries
  • Foot (max of 11 total injections)
    • Up to 4 x 5 unit (0.2 mL) injections to dorsal interdigital spaces
    • 1 x 5 unit (0.2 mL) injections to bifurcation of dorsalis pedis arteries
    • 4 x 5 unit (0.2 mL) injections adjacent to the common plantar digital arteries
    • 2 x 5 unit (0.2 mL) injections adjacent to bifurcation of the medial and lateral plantar arteries
• Recommended injection depth is 2 – 5 mm for all sites
• Cumulative max of 10 units/kg or 340 units per session

Injection sites (images adapted from Huang et al¹ using ChatGPT2)



            Figure 2: (A) Dorsal surface (B) Plantar Surface

References:
<sup>1. Huang S, Byrd D, Laarakker A, Shahriari S, Borah G. Successful Treatment of Extracorporeal Membrane Oxygenation Induced Digital Ischemia in Infants Using Botulinum Toxin Type A. Asaio j. Jul 15 2025;doi:10.1097/mat.0000000000002510
2. ChatGPT Version December 11. OpenAI; 2025. https://chat.openai.com/</sup>