A Pilot Study: 0.2% vs. 0.5% Lidocaine For Intravenous Regional Anesthesia

Abstract

Background: Standard intravenous regional anesthesia (IVRA) uses 3 mg/Kg of 0.5% lidocaine. However, a lower dose, larger volume lidocaine may be as effective. Methods: Randomized single blind study of emergency department patients with closed Colles fractures reduced with either 3 mg/Kg (0.6 mL/Kg) 0.5 % lidocaine (N=11) or 2 mg/Kg (1.0 mL/Kg) 0.2% lidocaine (N=10). Anesthesia outcome measured with 4-category pain rating scale. Results: Analysis of pooled data showed no significant difference in pain rating between IVRA methods (p=0.35). There were no significant differences in age, tourniquet time, or vital signs between groups. Mean body weight was 11.3 Kg less in experimental group (p<0.05). Mean±SD lidocaine volume and dose (standard vs experimental) were: 46.7±6.9 mL vs 66.9±12.4 mL, and 233.7±35.2 mg vs 133±24.8 mg. One woman (standard group) experienced transient lidocaine toxicity. Conclusion: Low-dose lidocaine is as effective and may be safer than the standard dose for IVRA. This study was conducted in the Department of Emergency Medicine at Los Angeles County-University of Southern California Medical Center, Los Angeles, CA, USA.