Pretreatment of lacerations with lidocaine, epinephrine, and tetracaine at triage: A randomized double-blind trial

Objective: Pretreatment of lacerations with topical anesthetics reduces the pain of subsequent anesthetic injection yet requires time. This study was conducted to determine the ability of triage nurses to identify lacerations necessitating closure and pretreat them with a topical anesthetic and to compare the pain levels of lidocaine injection in lacerations pretreated with LET (lidocaine 2%, epinephrine 1:1,000, tetracaine 2%) vs a placebo. Methods: This was a double-blind, randomized clinical trial that included consecutive emergency department patients aged ≥ 1 year with clean, non-bite lacerations ≤ 6 hours old. At triage the lacerations were randomized to LET solution or a placebo containing epinephrine 1:1,000. At examination an emergency practitioner assessed the laceration edges for the presence of blanching and adequacy of anesthesia to a 27-gauge needlestick. At the practitioner's discretion, supplemental lidocaine was infiltrated through the wound and the patient (or guardian) recorded the pain of infiltration on a 100-mm visual analog scale marked 'most pain' at the high end. The mean levels of pain of lidocaine infiltration were compared between groups with a t-test and the proportions of adequately anesthetized wounds were compared with a X² test. A sample of 40 patients had 80% power to detect a 20-mm between-group difference in the pain of injection (α = 0.05). Results: Of 43 patients enrolled (mostly children and males), 22 received LET and 21 placebo. The groups were similar for baseline characteristics. Lacerations in the LET group were more frequently adequately anesthetized (46% vs 14%, p = 0.03), and LET patients experienced less pain from injection than controls (22 mm vs 42 mm, p = 0.02). Conclusions: Application of LET by triage nurses is more effective than placebo in adequately anesthetizing simple lacerations in normal hosts and decreases the pain of local anesthetic infiltration.