Comparison of three modified lidocaine solutions for use in eyelid anesthesia

Purpose: To compare pain on injection and the efficacy of anesthesia of thr ee modified lidocaine solutions for use in eyelid surgery: 1) 2% lidocaine with 1:100,000 epinephrine, 2) 2% lidocaine with 1:100,000 epinephrine buff ered 9:1 with 8.4% sodium bicarbonate, and 3) 2% lidocaine with 1:100,000 e pinephrine diluted 1:9 with 0.9% bacteriostatic saline solution (with benzy l alcohol). Methods: In this prospective, randomized, double-masked, controlled clinica l trial, 30 consecutive patients undergoing bilateral identical eyelid surg ery were randomized to one of three treatment groups. Group I received buff ered solution on one side and stock solution on the other, group 2 received bacteriostatic saline diluted solution on one side and stock solution on t he other, and group 3 received buffered solution on one side and bacteriost atic saline diluted solution on the other. Patients used a 5-point scale to rate the perceived pain on injection and the pain felt during the operativ e procedure. Results: Comparison of mean injection pain scores showed that buffered solu tion was significantly less painful than unmodified solution (2.2 versus 3. 1, p < 0.05), bacteriostatic saline modified solution was significantly les s painful than unmodified solution (0.9 versus 3.3, p < 0.05), and bacterio static saline modified solution was significantly less painful than buffere d solution (1.2 versus 2.3, p < 0.05). Comparison of mean intraoperative pa in scores demonstrated no significant difference between the solutions in a ny of the treatment groups. Conclusions: For local anesthesia in eyelid surgery, bacteriostatic saline modified solution provides more comfort on injection than either buffered o r unmodified lidocaine-epinephrine solution and provides an adequate level of anesthesia that does not differ significantly from either the buffered o r unmodified solutions.