硫酸镁对布比卡因蛛网膜下腔阻滞的影响

Influence of intravenous injection of magnesium sulfate on efficacy of spinal anesthesia with bupivacaine

目的研究术前单次静脉注射硫酸镁对布比卡因蛛网膜下腔阻滞效果的影响。方法择期妇科手术患者45例随机均分为三组,术前分别静注生理盐水50ml(A组)、硫酸镁15mg/kg(B组)及硫酸镁25mg/kg(C组)。5min后进行布比卡因蛛网膜下腔阻滞。记录用药后蛛网膜下腔阻滞效果及循环变化,同时检测用药前后的血清镁(Mg2+)浓度。结果A组7例、B组6例、C组5例因硬膜外追加药物被排除出本研究。三组患者静脉用药前血清Mg2+浓度差异无统计学意义。术毕A、B组血清Mg2+浓度较术前均明显降低(P<0.01),且明显低于C组(P<0.01)。三组患者蛛网膜下腔阻滞起效时间差异无统计学意义,痛、温觉阻滞持续时间差异无统计学意义;C组运动阻滞持续时间明显长于A、B组(P<0.05)。结论术前单次静脉注射硫酸镁25mg/kg可延长布比卡因脊麻运动阻滞的持续时间。

Objective To investigate the influence of preoperative single intravenous injection of magnesium sulfate （MgSO4）on the efficacy of spinal anesthesia with bupivacaine. Methods Forty five patients scheduled for elective gynecological operations were randomly divided into three groups of 0.9% NaCl 50 ml（group A）, MgSO4 15 mg/kg（group B） and MgSO4 25 mg/kg（group C）. The drugs were injected intravenously and spinal anesthesia was performed at 5 min after the injection. The efficiency was evaluated and serum concentration of Mg^2＋ was detected before and at the end of surgery. Results There was no significantly difference in serum concentration of Mg^2＋ among three groups before anesthesia. The serum concentration of Mg^2＋ was significantly lower in groups C and A than that before and that in group A at the end of operation（P〈0. 01）. The onset of spinal anesthesia was not different among three groups. The duration of motor blockade was significantly longer in group B than that in groups C and A（P〈0.05）. Conclusion Intravenous injection of MgSO4 25 mg/ kg before spinal block can prolong the duration of motor blockade of spinal anesthesia with bupivacaine.