How does infiltration anesthesia work for repairing a skin cut?

Infiltration anesthesia is a method of local anesthesia used to facilitate minor surgical procedures, such as the repair of a skin laceration.

The process works by injecting an anesthetic agent, such as lidocaine, subcutaneously around the sensory nerve endings in the immediate area of the cut. These anesthetic molecules are hydrophobic, allowing them to penetrate the fatty membranes of the nerve fibers. Once inside, they block the ion channels that normally allow sodium ions to flow during nerve excitation. By preventing this movement of ions, the anesthetic temporarily blocks the conduction of nerve impulses that transmit pain signals to the brain.12

Because the fibers responsible for conveying dull aching pain are among the thinnest and most susceptible to these drugs, the patient experiences a localized loss of pain sensation while remaining conscious. The effect persists until the drug is dispersed, metabolized, and excreted by the body.1