Does the use of topical lidocaine, epinephrine, and tetracaine solution provide sufficient anesthesia for laceration repair?

OBJECTIVE: To determine: 1) the effectiveness of lidocaine, epinephrine, and tetracaine (LET) solution in eliminating or reducing the pain experienced in suturing superficial lacerations in adult patients; and 2) the effectiveness of LET in reducing the pain of local anesthetic injection.

METHODS: A prospective, randomized, double-blind study in which 60 adult patients with superficial lacerations were entered was conducted in the ED of a community-based teaching hospital affiliated with the University of Toronto. Following application of the LET or placebo (sterile water) solution to the laceration, a visual analog pain scale was recorded by the patient upon needle probing of the wound margin. If probing was painless, the laceration was repaired using LET alone. If injection of local anesthetic was required, an additional pain scale was elicited to quantify the attenuation of the pain of injection by the prior application of LET.

RESULTS: Pain scale values on needle probing were significantly reduced in the LET group vs the placebo group (medians of 4.0 vs 5.0 cm, respectively; p < 0.05). Only 13 of the 30 patients in the LET group required additional anesthetic, while all 30 patients in the placebo group requested local anesthetic. Pain scale values on injection of local anesthetic were not significantly different between the LET and placebo groups (medians of 3.5 vs 5.0 cm, respectively; p = 0.09), although there was a trend for lower pain scale values for those patients who received LET. No adverse effects were noted after the application of either LET or placebo solution. Follow-up was achieved for 54 of 60 patients with only 1 complication (a wound infection) reported in the LET group.

CONCLUSIONS: Significantly fewer patients require an injectable anesthetic when LET is applied. Those who do require an injection may experience less discomfort. These advantages should be balanced against the 20 to 30 minutes necessary for the LET to take effect.