Sun Jiehao, Feng Xiaona, Zhu Qihan, Lin Wendong, Guo Hailei, Ansong Emmanuel, Liu Le
Department of Anesthesiology, 1st Affiliated Hospital, Wenzhou Medical University, Wenzhou, China.
Department of Endocrinology, 1st Affiliated Hospital, Wenzhou Medical University, Wenzhou, China.
PLoS One. 2017 May 2;12(5):e0176589. doi: 10.1371/journal.pone.0176589. eCollection 2017.
High concentrations of local anesthetics may be neurotoxic for diabetic patients. Additive perineural administration of magnesium was reported to decrease the consumption of local anesthetics for nerve block. It was hypothesized that MgSO4 added to dilute ropivacaine was equianalgesic to more concentrated ropivacaine for toe amputations in diabetic patients.
Seventy diabetic patients were allocated into 3 groups: 1) perineural 200 mg MgSO4 added to 0.25% ropivacaine, 2) 0.25% ropivacaine alone, and 3) 0.375% ropivacaine alone. All patients underwent popliteal sciatic nerve block that was guided by ultrasonography using the respective regimens. Time of onset, duration of motor and sensory block were recorded. Spontaneous and evoked pain score, worst pain score, additional analgesic consumption, satisfaction score and initial time of analgesic requirement of each patient were documented up to 48 hours postoperatively.
In comparison with 0.25% ropivacaine alone, magnesium supplement prolonged the duration of sensory block (p = 0.001), as well as better evoked pain score at 6 hour postoperatively (p = 0.001). In comparison with evoked pain score (1.6/10) in group of 0.375% ropivacaine, magnesium plus 0.25% ropivacaine presented a little higher score (2.5/10) at 6 hour postoperatively (p = 0.001), while lower worst pain score (p = 0.001) and less postoperative total analgesic consumption (p = 0.002).
The regimen of adding 200mg MgSO4 to 0.25% ropivacaine for sciatic nerve block yields equal analgesic effect in comparison with 0.375% ropivacaine. These findings have suggested that supplemental MgSO4 could not improve analgesic quality except reducing the total amount of local anesthetics requirement in diabetic toe amputations with sciatic nerve blocks.
高浓度局部麻醉药可能对糖尿病患者具有神经毒性。据报道，经神经周围添加镁可减少神经阻滞时局部麻醉药的用量。研究假设，对于糖尿病患者的足趾截肢手术，添加硫酸镁的稀释罗哌卡因与浓度更高的罗哌卡因镇痛效果相当。
70例糖尿病患者被分为3组：1）在0.25%罗哌卡因中经神经周围添加200mg硫酸镁；2）单纯使用0.25%罗哌卡因；3）单纯使用0.375%罗哌卡因。所有患者均接受超声引导下的腘窝坐骨神经阻滞，采用各自的方案。记录起效时间、运动和感觉阻滞持续时间。记录每位患者术后48小时内的自发痛和诱发痛评分、最痛评分、额外镇痛药用量、满意度评分及首次镇痛需求时间。
与单纯使用0.25%罗哌卡因相比，添加镁可延长感觉阻滞持续时间（p = 0.001），且术后6小时诱发痛评分更佳（p = 0.001）。与0.375%罗哌卡因组术后6小时的诱发痛评分（1.6/10）相比，硫酸镁加0.25%罗哌卡因组评分略高（2.5/10）（p = 0.001），但最痛评分更低（p = 0.001），术后总镇痛药用量更少（p = 0.002）。
在0.25%罗哌卡因中添加200mg硫酸镁用于坐骨神经阻滞的方案与0.375%罗哌卡因镇痛效果相当。这些发现表明，在糖尿病足趾截肢坐骨神经阻滞中，补充硫酸镁除了可减少局部麻醉药总需求量外，不能改善镇痛质量。
