Comparison of Bier Block and Lidocaine-Propofol Mixture for Prevention of Propofol Injection Pain

The goal of this clinical trial was to evaluate methods to prevent pain on intravenous administration of propofol during induction of anesthesia. Propofol frequently causes a burning or painful sensation when injected into a peripheral vein. This randomized study compared three approaches in adult patients scheduled for elective surgery: propofol alone (control), propofol with 40 mg lidocaine mixed directly, and a brief intravenous lidocaine under venous occlusion (Bier block) using 40 mg for 2 minutes before propofol. The primary outcome was the incidence of pain on propofol injection measured with a 4-point verbal rating scale (0 = no pain to 3 = severe pain). Secondary outcomes included pain intensity, peri-induction hemodynamic parameters, and local injection-site adverse effects.