Lidocaine administration techniques for head and limb wound anesthesia: Injection vs. topical application

Purpose: Lidocaine is one of the most utilized anesthetics used in different forms and various clinical contexts. Recently there have been controversy about the best method of lidocaine administration and there have been studies comparing subcutaneous and topical lidocaine in different clinical fields. The present study aims to compare the effect of topical and subcutaneous injection of lidocaine in patients presenting with ulcerations in their head and extremities. Methods: This single-center cross-sectional study, conducted from April 2016 to April 2017 at Imam Reza Medical Educational Center, Tabriz, Iran, included patients with extremity lacerations under 3 cm, excluding cases with bites, joint or ear injuries, specific medications, cardiac or neuropathic histories, and epilepsy. Ethical approval and informed consent were obtained. Data were collected via questionnaires by trained interviewers. Patients received either topical or subcutaneous lidocaine as per clinical practice, without randomization. Pain was measured using a 100-mm visual analogue scale (VAS). Data analysis utilized SPSS v22.0, with significance set at p < 0.05 and 80 % study power. Results: In this observational study of 305 patients, 162 received subcutaneous lidocaine and 143 received topical lidocaine. No significant differences in age or gender were found (P = 0.25 and P = 0.86). Patients with topical lidocaine reported higher starting pain, while those receiving subcutaneous lidocaine experienced significantly more pain during administration and suturing (P < 0.05), highlighting the impact of lidocaine application methods on patient pain experiences. Conclusion: The difference in pain during administration between the two methods was statistically and clinically significant, while the difference in pain during suturing was statistically significant but not clinically meaningful. These findings suggest that topical lidocaine offers a less painful alternative to subcutaneous injection, particularly during administration.