Elsayed Hitham M A, Al-Metwalli Roshdi R, Abdelraheem Mohammed, Badawy Fawzy
Department of Anesthesiology, Imam Abdulrahman Bin Faisal University, Al-Khobar, Saudi Arabia.
Department of Anesthesia and ICU, Sohag University, Egypt.
Saudi J Anaesth. 2025 Oct-Dec;19(4):494-497. doi: 10.4103/sja.sja_55_25. Epub 2025 Sep 3.
To determine the median effective dose (ED50) of 2% lidocaine mixed with propofol for preventing pain during the induction of anesthesia using a modified Dixon's up-and-down method.
Thirty ASA (American Society of Anesthesiologists) grade I and II patients, aged 18-60 years, undergoing elective surgery were enrolled. Using the modified Dixon's up-and-down method, patients received varying doses of lidocaine mixed with 20 mL of propofol MCT/LCT (Medium Chain Triglyceride/Long Chain Triglyceride) emulsion. The primary outcome was the calculation of the ED50 of 2% lidocaine, defined as the midpoint dose at which 50% of patients experienced painless injection. Secondary outcomes included pain scores during injection, heart rate changes, and withdrawal movements.
Thirty patients completed the study. The ED50 of lidocaine premixed with 20 mL of propofol MCT/LCT emulsion to prevent pain during the induction of anesthesia was 32.14 mg (95% CI = 32.09 mg-32.18 mg), equivalent to 1.46 mg/mL (95% CI: 1.02 mg/mL-1.91 mg/mL). Demographic and clinical characteristics of patients who experienced pain and those who did not were not statistically significant.
Our study concluded that the ED50 of lidocaine premixed with 20 mL of propofol to prevent pain during the induction of anesthesia was 32.14 mg (95% CI = 32.09 mg-32.18 mg), equivalent to 1.46 mg/mL (95% CI: 1.02-1.91 mg/mL).
采用改良的 Dixon 上下法确定 2%利多卡因与丙泊酚混合用于预防麻醉诱导期疼痛的半数有效剂量（ED50）。
纳入 30 例年龄在 18 - 60 岁、接受择期手术的美国麻醉医师协会（ASA）I 级和 II 级患者。采用改良的 Dixon 上下法，患者接受不同剂量的利多卡因与 20 mL 丙泊酚中长链脂肪乳剂（MCT/LCT）混合液。主要结局是计算 2%利多卡因的 ED50，定义为 50%患者注射时无痛的中点剂量。次要结局包括注射时的疼痛评分、心率变化和退缩动作。
30 例患者完成研究。与 20 mL 丙泊酚 MCT/LCT 乳剂预混合以预防麻醉诱导期疼痛的利多卡因 ED50 为 32.14 mg（95%置信区间 = 32.09 mg - 32.18 mg），相当于 1.46 mg/mL（95%置信区间：1.02 mg/mL - 1.91 mg/mL）。经历疼痛和未经历疼痛的患者的人口统计学和临床特征无统计学差异。
我们的研究得出结论，与 20 mL 丙泊酚预混合以预防麻醉诱导期疼痛的利多卡因 ED50 为 32.14 mg（95%置信区间 = 32.09 mg - 32.18 mg），相当于 1.46 mg/mL（95%置信区间：1.02 - 1.91 mg/mL）。
