COMPARISON OF TETRACAINE-ADRENALINE-COCAINE (TAC) WITH TOPICAL LIDOCAINE-EPINEPHRINE (TLE) - EFFICACY AND COST

Topical anesthesia in the form of TAC (tetracaine, adrenaline, cocaine ) solution has been used for wound repair. This pilot study was design ed to determine if the topical anesthesia achieved using a mixture of lidocaine (5%) and epinephrine (1:2000) (TLE) is equivalent to the top ical anesthesia obtained using a solution of tetracaine (0.5%), epinep hrine (1:2000), and cocaine (10.4%) (TAG). A prospective, randomized, double-blind trial was carried out from May 1992 to August 1992 at a c ommunity-based teaching hospital Emergency Department (ED) that receiv es 50,000 annual visits. Patients with facial or scalp lacerations sui table for topical anesthesia presenting to the ED were included when s tudy physicians were in attendance. Exclusion criteria included the pr esence of a sensory altering substance (eg, ethanol), age younger than two years, hypertension, pregnancy, allergy to any of the study's pha rmacological agents, wounds greater than six hours old, grossly contam inated wounds, and wounds longer than six centimeters. Either a TAC or TLE solution was applied to lacerations before suturing. The lacerati on was repaired and the patient or physician evaluated the degree of p ain from the procedure by using a standardized visual pain scale. A to tal of 35 patients were studied. Seventeen patients were in the TLE gr oup; 18 in the TAC group. The mean ages were compared and found to be similar (P = .40) between the two test groups. The pain scale values, the diameter of tissue blanch around laceration (halo size), and the t ime to laceration repair from the onset of application of anesthetic w ere compared and no difference was shown between the TAC and TLE group s. The correlation between the pain scores and the halo size was deter mined. In the TLE group, a small halo size was associated with a highe r pain scale score; in the TAC group this correlation was not apparent . TLE is equivalent to TAC in many respects, especially in producing t opical anesthesia. In an average month, 4.6% of the patients seen in t he ED of the study site have facial and scalp lacerations amenable to topical anesthesia. The annual cost savings from using TLE instead of TAC is estimated to he 560,000 at the institution studied. The TLE sol ution also eliminates the potential toxicity from cocaine and tetracai ne. Copyright (C) 1995 by W.B. Saunders Company