Digital Blocks
Digital blocks are the preferred type of anesthesia for procedures done distal to the PIP joint. Caution should be used when giving digital blocks after injury to the digital artery that may require revascularization because the digital nerves and arteries run together. Digital blocks should also not be given when there is an infection around the MP joint.
A 25-gauge, 1½-in. needle is inserted distally in the web space where the skin innervation is less dense than in the palm (Fig. 1). The needle is advanced under the dorsal skin to the MP joint and 1 mL of anesthetic is injected into the subcutaneous space. The needle is withdrawn half way and directed palmarly between the MP joints. The needle is advanced until it is almost subcutaneous. Two to three milliliters are injected palmarly. The procedure is then repeated on the other side of the digit.
In the thumb, the two digital nerves are more palmar and closer together than in the digit. The ulnar digital nerve lies just palmar to the first web and the radial digital nerve lies just radial to the midline. Both nerves can be blocked by inserting the needle from ulnar to radial into the first web space at the MP joint. Two to three milliliters of anesthetic are injected transversely along the MP crease. Dorsal injections are given via sites at the radial and ulnar borders of the MP joint. Care should be taken to not give a “ring block,” or circumferential injection at the MP joint. This block may tightly compress the tissues and compromise vascularity of the digit. As with any block in the hand, no effort is made to elicit paresthesias during the injection. The needle should be withdrawn and replaced in order to avoid injection into the nerve if paresthesias are elicited.
Digital blocks are the preferred type of anesthesia for procedures done distal to the PIP joint. Caution should be used when giving digital blocks after injury to the digital artery that may require revascularization because the digital nerves and arteries run together. Digital blocks should also not be given when there is an infection around the MP joint.
A 25-gauge, 1½-in. needle is inserted distally in the web space where the skin innervation is less dense than in the palm (Fig. 1). The needle is advanced under the dorsal skin to the MP joint and 1 mL of anesthetic is injected into the subcutaneous space. The needle is withdrawn half way and directed palmarly between the MP joints. The needle is advanced until it is almost subcutaneous. Two to three milliliters are injected palmarly. The procedure is then repeated on the other side of the digit.
In the thumb, the two digital nerves are more palmar and closer together than in the digit. The ulnar digital nerve lies just palmar to the first web and the radial digital nerve lies just radial to the midline. Both nerves can be blocked by inserting the needle from ulnar to radial into the first web space at the MP joint. Two to three milliliters of anesthetic are injected transversely along the MP crease. Dorsal injections are given via sites at the radial and ulnar borders of the MP joint. Care should be taken to not give a “ring block,” or circumferential injection at the MP joint. This block may tightly compress the tissues and compromise vascularity of the digit. As with any block in the hand, no effort is made to elicit paresthesias during the injection. The needle should be withdrawn and replaced in order to avoid injection into the nerve if paresthesias are elicited.
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