Comparison of topical anesthetics with lidocaine infiltration during laceration repair in children.

This study is a randomized, blinded trial that compares the effectiveness of a new topical anesthetic preparation of 2% mepivacaine and 1:100,000 norepinephrine (Mepivanor); a topical solution of 1% tetracaine, 1:4,000 adrenaline, and 4% cocaine (TAC); and 1% lidocaine infiltration during laceration repair in children. The study was conducted in the emergency department of a large academic children's hospital. Study participants were children 2 years of age or older with a laceration on the face or scalp, 5 cm or less in length, that required suturing. Patients were randomly assigned to receive Mepivanor topical solution, TAC topical solution, or lidocaine infiltration anesthesia prior to laceration repair. Seventy-one patients were enrolled in the study during a 2-month period. Outcome measures assessed pain perceptions using a Visual Analogue Scale (VAS) and a seven-point Likert scale. There was statistical power to detect differences of 1.2 to 1.7 units for the VAS outcome measures using alpha = 0.05 and beta = 0.20. There were no statistically significant (P > 0.05) differences between TAC and 1% lidocaine infiltration in providing effective anesthesia. Mepivanor was generally less effective in providing adequate anesthesia during laceration repair than TAC and lidocaine infiltration, with Tukey's post hoc test for ANOVA demonstrating statistically significant (P < 0.05) differences between Mepivanor and these agents for research assistant and suture technician VAS scores. Wound blanching was judged to be less with Mepivanor than with TAC, although this difference was not statistically significant. There were no adverse reactions, wound infections, or healing difficulties for any of the patients who received TAC or Mepivanor. It was concluded that non-cocaine-containing Mepivanor was generally less effective than TAC and lidocaine infiltration in providing adequate local anesthesia during laceration repair. TAC containing only 120 mg of cocaine (3 mL of 4% cocaine) was as effective as 1% lidocaine infiltration in providing local anesthesia during laceration repair. This will allow the amount of cocaine in TAC to be reduced, thereby decreasing costs and the likelihood of adverse reactions.