Digital nerve block

There are 4 digital nerves to block

• 2 Palmar - Dominant source of innervation
• 2 Dorsal

Local Anaesthetic without adrenaline

Conventional ring block

Requires 2 needle sticks

Insert needle into the dorsal-lateral aspect of the proximal phalanx in the web space just distal to the metacarpalphalangeal joint to anaesthetize
the dorsal nerve. The needle is then advanced until it touches bone, where 0.5 mL of the anaesthetic is deposited. Without reinserting the needle, it is
slightly withdrawn and then advanced toward the volar surface, where 1 mL of anesthetic is injected. The procedure is then repeated on the opposite side of  the digit to complete the block.

Wait 5 minutes.

Transthecal digital block

Chiu first described the transthecal digital block in 1990 achieving 99% success, failures tend to occur in the thumb and big toe.

It is essential to use a small needle (25 gauge or higher) and to pay careful attention to sterile technique to minimize the risk. Infection within the sheath

Method

Traditional site flexor tendon on the palmar surface just proximal to the metacarpophalangeal joint Alternative use the metacarpal crease on the palmar surface 2ml Local anaesthetic locate the midpoint of the metacarpal crease on the palmar surface Apply pressure with your nondominant thumb proximal to the injection site; directs the flow of the anaesthetic distally. Hold for 30 seconds after injection. Insert the needle perpendicular to the skin until you hit bone. Withdraw the syringe slightly, and inject the medication. Wait 3-5 minutes

 Chiu DTW. Transthecal digital block: flexor tendon sheath used for anesthetic infusion. J Hand Surg 1990;15:471-3.

Last updated 11/09/15