Local Anesthesia and Electronic Injector

Local anesthesia-related pain is associated with injection speed. An electronic constant-speed injector was developed for slow and steady injection to alleviate dermatological anesthesia pain. The investigators aimed to validate the efficacy of an electronic constant-speed injector in reducing pain during local infiltrative anesthesia by comparing it to the conventional manual injection method. Patients who underwent local infiltrative anesthesia in an area \>5 cm during scalp surgery were selected. Each side of the surgical field was randomly assigned a manual or electronic injector for local infiltration. Each participant used the numeric rating scale (NRS) to rate infiltration-related pain on each side.