J Cutan Med Surg 2019 Nov/Dec;23(6):602-607. Epub 2019 Aug 12.
Division of Dermatologic Surgery, Department of Dermatology, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
Background: Local anesthetic injections can be painful and distressing.
Objective: The aim of this study was to determine whether nitrous oxide, ice, vibration, or topical anesthetic improves analgesia for local anesthetic injections.
Method: A cohort study of 400 patients undergoing Mohs micrographic surgery with local anesthetic was conducted. Patients received no intervention ( = 200), ice ( = 50), topical anesthetic cream ( 50), vibration device ( = 50), or nitrous oxide ( = 50). Pain was rated using the Visual Analogue Scale (VAS) and Wong-Baker FACES Pain Rating Scale.
Results: Without intervention, mean VAS was 4.2 and FACES was 4.6. Nitrous oxide was the most successful in reducing pain (mean VAS 1.6 vs. 4.2, < .01, FACES 1.2 vs. 4.6, < .01). Topical ice reduced pain (mean VAS 3.0 vs. 4.2, < .01, FACES 3.0 vs. 4.6, < .01). Vibration reduced pain (mean VAS 3.5 vs. 4.2, < .01, FACES 3.6 vs. 4.6, < .01). Higher pain scores were associated with age <50 ( = .02), male sex ( = .05), and surgery on the nose, lip, ear, or eyelid ( = .02).
Conclusion: Nitrous oxide, ice, and vibration reduce injection pain. These interventions are especially useful for younger males undergoing surgery on the nose, lip, ear, or eyelid.