Anesthesiology, Ohio State University Wexner Medical Center, Columbus, Ohio, USA.
Anesthesiology, University of Michigan, Ann Arbor, Michigan, USA.
Reg Anesth Pain Med. 2021 Aug;46(8):704-712. doi: 10.1136/rapm-2020-102353. Epub 2021 May 11.
Dexmedetomidine is an effective local anesthetic adjunct for peripheral nerve blocks. The intravenous route for administering dexmedetomidine has been suggested to be equally effective to the perineural route; but comparative evidence is conflicting.
This evidence-based review evaluated trials comparing the effects of intravenous to perineural dexmedetomidine on peripheral nerve block characteristics in adult surgical patients. Our primary aim was to evaluate the durations of sensory and motor blockade. Duration of analgesia, onset times of sensory and motor blockade, analgesic consumption, rest pain, and dexmedetomidine-related adverse events were evaluated as secondary outcomes.
We sought randomized trials comparing the effects of intravenous to perineural dexmedetomidine on peripheral nerve block characteristics. The Cochrane Risk of Bias tool and the Grades of Recommendation, Assessment, Development, and Evaluation criteria was used to evaluate the quality of evidence for when an outcome was reported by at least three studies.
Ten studies compared intravenous and perineural dexmedetomidine in the setting of upper extremity blocks (seven), lower extremity blocks (two), and truncal block (one). The doses of dexmedetomidine supplementing long-acting local anesthetics varied between a predetermined dose (50 μg) and a weight-based dose (0.5 μg/kg-1.0 μg/kg). Clinical diversity precluded quantitative pooling; and evidence is presented as a systematic review. Compared with the intravenous route, moderate quality evidence found that perineural dexmedetomidine prolonged the duration of sensory blockade in four of six trials and motor blockade in five of seven trials. Perineural dexmedetomidine also hastened the onset of sensory and motor blockade in three of six trials. No differences were reported for the remaining outcomes; and intravenous dexmedetomidine was not superior for any outcome in any of the trials.
Moderate quality evidence appears to suggest that intravenous dexmedetomidine is an inferior peripheral nerve block adjunct compared with perineural dexmedetomidine. Perineural dexmedetomidine is associated with longer durations and faster onset of sensory and motor blockade.
右美托咪定是一种有效的局部麻醉辅助药物，可用于外周神经阻滞。静脉途径给予右美托咪定与神经周围途径同样有效；但比较证据存在争议。
本循证综述评估了比较静脉内和神经周围给予右美托咪定对成人手术患者外周神经阻滞特征的影响的试验。我们的主要目的是评估感觉和运动阻滞的持续时间。还评估了镇痛持续时间、感觉和运动阻滞的起效时间、镇痛药物消耗、静息痛和右美托咪定相关不良反应作为次要结局。
我们寻找了比较静脉内和神经周围给予右美托咪定对外周神经阻滞特征影响的随机试验。使用 Cochrane 偏倚风险工具和建议、评估、制定和评估（GRADE）标准来评估至少有三项研究报告的结局的证据质量。
十项研究比较了上肢阻滞（七项）、下肢阻滞（两项）和躯干阻滞（一项）中静脉内和神经周围给予右美托咪定的效果。补充长效局部麻醉剂的右美托咪定剂量在预定剂量（50μg）和基于体重的剂量（0.5μg/kg-1.0μg/kg）之间变化。临床多样性排除了定量汇总；并以系统综述的形式呈现证据。与静脉途径相比，六项试验中有四项发现神经周围给予右美托咪定延长了感觉阻滞的持续时间，七项试验中有五项发现运动阻滞的持续时间延长。神经周围给予右美托咪定还使三项试验中的感觉和运动阻滞的起效时间加快。其余结局未报告差异；并且在任何试验中，静脉内给予右美托咪定都没有在任何结局上具有优势。
中等质量证据似乎表明，与神经周围给予右美托咪定相比，静脉内给予右美托咪定是一种较差的外周神经阻滞辅助药物。神经周围给予右美托咪定与更长的感觉和运动阻滞持续时间和更快的起效时间相关。
