Department of Anesthesia and Perioperative Medicine, Schulich School of Medicine and Dentistry, University of Western Ontario, C3-106, University Hospital, 339 Windermere Road, London, ON, N6A 5A5, Canada.
Department of Anesthesia and Perioperative Medicine, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, Canada.
Can J Anaesth. 2021 Jul;68(7):1018-1027. doi: 10.1007/s12630-021-01975-7. Epub 2021 Mar 31.
Intraoperative nerve dysfunction has been difficult to investigate because of its rarity and unpredictable occurrence. The diagnostic test attributes of nerve function monitors have not been clearly defined. This proof-of-concept study aimed to assess the feasibility of using brachial plexus blockade (BPB) in awake patients as an experimental model for nerve dysfunction to characterize the diagnostic test attributes of somatosensory evoked potentials (SSEPs).
We obtained baseline SSEPs and neurologic function in patients and subsequently placed BPBs (experimental model) to generate progressive states of nerve dysfunction. We monitored SSEP changes (index test) and neurologic symptoms (reference standard) simultaneously during the onset of BPB to determine the temporal relationships and diagnostic test attributes of SSEPs.
Brachial plexus blockade produced differential motor and sensory dysfunction that allowed simultaneous clinical and neurophysiologic assessment. One hundred and fifty-seven pairs of multiple data points from 14 patients were included for final analysis. The onset of abnormal SSEP signals almost always preceded the onset of neurologic symptoms. The sensitivities and specificities of SSEP to detect the impairment of power (motor rating score ≤ 4/5), cold sensation, and two-point discrimination were 100% and 67%, 99% and 55%, and 100% and 46%, respectively.
This study found that BPB can produce sufficient differential nerve dysfunction to allow adequate evaluation of the diagnostic test attributes of SSEPs as a nerve monitor. The results of this study may stimulate further work on refining intraoperative nerve dysfunction models and diagnostic nerve function monitors.
www.clinicaltrials.gov (NCT03409536); registered 24 January 2018.
术中神经功能障碍难以研究，因为其罕见且发生不可预测。神经功能监测器的诊断测试属性尚未明确界定。本概念验证研究旨在评估在清醒患者中使用臂丛神经阻滞 (BPB) 作为神经功能障碍的实验模型的可行性，以描述体感诱发电位 (SSEP) 的诊断测试属性。
我们在患者中获得基线 SSEP 和神经功能，随后放置 BPB（实验模型）以产生进行性神经功能障碍状态。我们在 BPB 开始时同时监测 SSEP 变化（指标测试）和神经症状（参考标准），以确定 SSEP 的时间关系和诊断测试属性。
臂丛神经阻滞产生了不同的运动和感觉功能障碍，允许同时进行临床和神经生理评估。从 14 名患者中获得了 157 对多组数据点进行最终分析。异常 SSEP 信号的出现几乎总是先于神经症状的出现。SSEP 检测力量（运动评分≤4/5）、冷感和两点辨别力受损的敏感性和特异性分别为 100%和 67%、99%和 55%、100%和 46%。
本研究发现，BPB 可以产生足够的差异神经功能障碍，从而充分评估 SSEP 作为神经监测器的诊断测试属性。本研究的结果可能会刺激进一步改进术中神经功能障碍模型和诊断神经功能监测器的工作。
www.clinicaltrials.gov（NCT03409536）；2018 年 1 月 24 日注册。
