Background 

The risk of neurologic symptoms after regional anesthesia in orthopaedic surgery is estimated to approach 3%, with long-term deficits affecting 2 to 4 per 10,000 patients. However, current estimates are derived from large retrospective or observational studies that are subject to important systemic biases. Therefore, to harness the highest quality data and overcome the challenge of small numbers of participants in individual randomized trials, we undertook this systematic review and meta-analysis of contemporary randomized trials.

Questions/purposes 

In this systematic review and meta-analysis of randomized trials we asked: (1) What is the aggregate pessimistic and optimistic risk of postoperative neurologic symptoms after regional anesthesia in upper extremity surgery? (2) What block locations have the highest and lowest risk of postoperative neurologic symptoms? (3) What is the timing of occurrence of postoperative neurologic symptoms (in days) after surgery?

Methods 

We searched Ovid MEDLINE, Embase, Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews, Web of Science, Scopus, and PubMed for randomized controlled trials (RCTs) published between 2008 and 2019 that prospectively evaluated postoperative neurologic symptoms after peripheral nerve blocks in operative procedures. Based on the Grading of Recommendations, Assessment, Development, and Evaluation guidance for using the Risk of Bias in Non-Randomized Studies of Interventions tool, most trials registered a global rating of a low-to-intermediate risk of bias. A total of 12,532 participants in 143 trials were analyzed. Data were pooled and interpreted using two approaches to calculate the aggregate risk of postoperative neurologic symptoms: first according to the occurrence of each neurologic symptom, such that all reported symptoms were considered mutually exclusive (pessimistic estimate), and second according to the occurrence of any neurologic symptom for each participant, such that all reported symptoms were considered mutually inclusive (optimistic estimate).

Results 

At any time postoperatively, the aggregate pessimistic and optimistic risks of postoperative neurologic symptoms were 7% (915 of 12,532 [95% CI 7% to 8%]) and 6% (775 of 12,532 [95% CI 6% to 7%]), respectively. Interscalene block was associated with the highest risk (13% [661 of 5101] [95% CI 12% to 14%]) and axillary block the lowest (3% [88 of 3026] [95% CI 2% to 4%]). Of all symptom occurrences, 73% (724 of 998) were reported between 0 and 7 days, 24% (243 of 998) between 7 and 90 days, and 3% (30 of 998) between 90 and 180 days. Among the 31 occurrences reported at 90 days or beyond, all involved sensory deficits and four involved motor deficits, three of which ultimately resolved.

Conclusion 

When assessed prospectively in randomized trials, the aggregate risk of postoperative neurologic symptoms associated with peripheral nerve block in upper extremity surgery was approximately 7%, which is greater than previous estimates described in large retrospective and observational trials. Most occurrences were reported within the first week and were associated with an interscalene block. Few occurrences were reported after 90 days, and they primarily involved sensory deficits. Although these findings cannot inform causation, they can help inform risk discussions and clinical decisions, as well as bolster our understanding of the evolution of postoperative neurologic symptoms after regional anesthesia in upper extremity surgery. Future prospective trials examining the risks of neurologic symptoms should aim to standardize descriptions of symptoms, timing of evaluation, classification of severity, and diagnostic methods.

Level of Evidence 

Level I, therapeutic study.

中文翻译：

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上肢手术区域麻醉后出现术后神经症状的风险有哪些？随机试验的系统回顾和荟萃分析

 背景

骨科手术局部麻醉后出现神经系统症状的风险估计接近 3%，每 10,000 名患者中就有 2 至 4 名患者受到长期神经症状的影响。然而，目前的估计来自大型回顾性或观察性研究，这些研究存在重要的系统偏差。因此，为了利用最高质量的数据并克服个体随机试验中参与者数量较少的挑战，我们对当代随机试验进行了系统回顾和荟萃分析。

 问题/目的

在这项随机试验的系统回顾和荟萃分析中，我们提出了以下问题：（1）上肢手术局部麻醉后出现术后神经系统症状的总体悲观和乐观风险是多少？ (2) 哪些阻滞位置术后神经系统症状的风险最高和最低？ (3) 术后神经系统症状出现的时间（以天为单位）是多少？

 方法

我们检索了 Ovid MEDLINE、Embase、Cochrane 对照试验中央注册库和 Cochrane 系统评价数据库、Web of Science、Scopus 和 PubMed，查找 2008 年至 2019 年间发表的随机对照试验 (RCT)，前瞻性评估周围神经阻滞术后的神经系统症状在操作过程中。根据非随机干预研究工具中使用偏倚风险的建议分级、评估、制定和评价指南，大多数试验的全球评级为低至中偏风险。总共分析了 143 项试验的 12,532 名参与者。使用两种方法汇总和解释数据，以计算术后神经系统症状的总风险：首先根据每种神经系统症状的发生，以便所有报告的症状被认为是相互排斥的（悲观估计），其次根据任何神经系统症状的发生每个参与者的神经系统症状，因此所有报告的症状被认为是相互包容的（乐观估计）。

 结果

术后任何时间，术后神经系统症状的总体悲观和乐观风险分别为 7%（12,532 例中的 915 例 [95% CI 7% 至 8%]）和 6%（12,532 例中的 775 例[95% CI 6% 至 7%]） ）， 分别。肌间沟阻滞与最高风险相关（13% [5101 中的 661] [95% CI 12% 至 14%]），腋窝阻滞风险最低（3% [3026 中的 88] [95% CI 2% 至 4%]） ）。在所有症状发生中，73%（998 例中的 724 例）在 0 至 7 天内报告，24%（998 例中的 243 例）在 7 至 90 天内报告，3%（998 例中的 30 例）在 90 至 180 天内报告。在 90 天或更长时间内报告的 31 起事件中，全部涉及感觉缺陷，4 起涉及运动缺陷，其中 3 起最终得到解决。

 结论

在随机试验中进行前瞻性评估时，上肢手术中与周围神经阻滞相关的术后神经症状的总风险约为 7%，高于先前大型回顾性和观察性试验中描述的估计值。大多数事件是在第一周内报告的，并且与肌间沟阻滞相关。 90 天后很少有发生这种情况的报道，而且主要涉及感觉缺陷。尽管这些发现不能说明因果关系，但它们可以帮助为风险讨论和临床决策提供信息，并增强我们对上肢手术局部麻醉后神经系统症状演变的理解。未来检查神经系统症状风险的前瞻性试验应旨在标准化症状描述、评估时间、严重程度分类和诊断方法。

 证据水平

I 级，治疗研究。