A randomized, double-blind comparison of the total dose of 1.0% lidocaine with 1:100,000 epinephrine versus 0.5% lidocaine with 1:200,000 epinephrine required for effective local anesthesia during Mohs micrographic surgery for skin cancers

Objective: We sought to compare total lidocaine dose and patient comfort when using 1.0% lidocaine with 1:100,000 epinephrine versus 0.5% lidocaine with 1:200,000 epinephrine during Mohs micrographic surgery. Methods: In all, 149 patients were randomized to receive 1.0% lidocaine with 1:100,000 epinephrine or 0.5% lidocaine with 1:200,000 epinephrine during Mohs micrographic surgery. The total dose of lidocaine and measures of patient comfort were recorded. Results: Compared with the 1.0% lidocaine group, there was a 52% reduction in lidocaine dose in the 0.5% group (mean difference, 147.85 mg; 95% confidence interval, 108.15-187.55; P < .001). Patient comfort was equivalent in both groups, as evidenced by the similar mean visual analog scale scores (P = .48) and mean volumes of rescue lidocaine administered (P = .18). Limitations: No lidocaine blood levels were measured, and one Mohs surgeon performed all surgeries. Conclusion: The dose of 0.5% lidocaine with 1:200,000 epinephrine provides pain control equivalent to 1.0% lidocaine with 1:100,000 epinephrine at approximately half the total lidocaine dose.