Tverskoy M, Shifrin V, Finger J, Fleyshman G, Kissin I
Department of Anesthesiology, Rebecca Sieff Hospital, Safed, Israel.
Reg Anesth. 1996 May-Jun;21(3):209-13.
The aim of the study was to determine the effect of epidural bupivacaine block on midazolam hypnotic requirements.
Sixty unpremedicated, ASA physical status I or II male patients, aged 45-65 years and scheduled for elective lower abdominal, pelvic, or lower limb surgery participated in this randomized, double-blind, placebo-controlled study. The study population was composed of three groups: Before administration of midazolam, patients in the first group received an intramuscular injection of 15 mL saline (M), those in the second group an intramuscular injection of 15 mL 0.5% bupivacaine (MIB), and those in the third group an epidural injection of 15 mL 0.5% bupivacaine at the L3-L4 level (MEB). Loss of the ability to respond to verbal command was used as an endpoint for the effect of midazolam injected intravenously in predetermined doses (five patients per dose) 30 minutes after a bupivacaine (or saline) injection. Midazolam dose-response curves were obtained by probit analysis.
The midazolam median effective dose values for the hypnotic effect were 0.20 mg/kg (95% confidence limit, 0.10-0.27 mg/kg) in the M group; 0.10 mg/kg (0.06-0.22 mg/kg) in the MIB group; and 0.04 mg/kg (0.03-0.07 mg/kg) in the MEB group. The differences between the midazolam median effective dose values had high levels of significance: P < .00001 for MEB versus M, P < .002 for MEB versus MIB, and P < .01 for MIB versus M.
Epidural bupivacaine block profoundly decreases midazolam hypnotic requirements. The most likely explanation for this effect is the reduction in afferent input induced by the block.
本研究旨在确定硬膜外布比卡因阻滞对咪达唑仑催眠需求的影响。
60例未接受术前用药、美国麻醉医师协会（ASA）身体状况为I或II级、年龄在45至65岁之间且计划进行择期下腹部、盆腔或下肢手术的男性患者参与了这项随机、双盲、安慰剂对照研究。研究人群分为三组：在给予咪达唑仑之前，第一组患者接受15 mL生理盐水肌肉注射（M组），第二组患者接受15 mL 0.5%布比卡因肌肉注射（MIB组），第三组患者在L3-L4水平接受15 mL 0.5%布比卡因硬膜外注射（MEB组）。在布比卡因（或生理盐水）注射30分钟后，以对预定剂量静脉注射咪达唑仑（每剂量5例患者）无语言指令反应能力的丧失作为终点。通过概率分析获得咪达唑仑剂量-反应曲线。
M组催眠效应的咪达唑仑中位有效剂量值为0.20 mg/kg（95%置信限，0.10 - 0.27 mg/kg）；MIB组为0.10 mg/kg（0.06 - 0.22 mg/kg）；MEB组为0.04 mg/kg（0.03 - 0.07 mg/kg）。咪达唑仑中位有效剂量值之间的差异具有高度显著性：MEB组与M组相比P <.00001，MEB组与MIB组相比P <.002，MIB组与M组相比P <.01。
硬膜外布比卡因阻滞显著降低咪达唑仑催眠需求。对此效应最可能的解释是阻滞引起的传入神经输入减少。
