LET versus EMLA for pretreating lacerations: A randomized trial

Objective: To compare the anesthetic efficacy of EMLA cream (eutectic mixture of local anesthetics) with that of LET solution (lidocaine, epinephrine, tetracaine) for pretreating lacerations prior to lidocaine injection. Methods: This was a randomized, double-blind clinical trial in a convenience sample of 60 patients aged 1 to 59 years with traumatic lacerations. Eligible wounds were uncomplicated, clean lacerations ≤ 6 hours old. Finger and toe lacerations were excluded. At the time of initial presentation to triage, patients were randomized to LET or EMLA. A nurse applied the topical anesthetic into the laceration with a 5-mL syringe. A physician assessed the laceration edges for the presence of blanching and adequacy of anesthesia to a 27-gauge needlestick. Supplemental lidocaine was then infiltrated through the wound edges and the pain of infiltration was recorded by the patient (or guardian) on a 100-mm visual analog scale marked "most pain" at the high end. A sample of 44 patients had 90% power to detect a 20-mm difference in injection pain (two-tailed α = 0.05). Results: Sixty patients were randomized to LET (29) or EMLA (31). Median age was 8.5 years; 23% were female. Most lacerations were facial and closed with sutures. There was no difference in baseline characteristics between groups. More wounds treated with LET were anesthetic to a needlestick than wounds treated with EMLA (73% vs 40%, p = 0.01); however, there was no between-group difference in the median pain of lidocaine infiltration (LET - 12 mm vs EMLA - 13 mm, p = 0.89). Conclusions: Pretreatment of simple lacerations with LET or EMLA at the time of patient presentation results in similar amounts of pain of subsequent local infiltration of lidocaine.