Nuffield Department of Anaesthetics, Oxford University Hospitals NHS Trust, Oxford, UK
Department of Psychology, School of Psychology and Cognition Institute, Plymouth University, Plymouth, UK.
Br J Anaesth. 2014 Oct;113(4):549-59. doi: 10.1093/bja/aeu313. Epub 2014 Sep 9.
We present the main findings of the 5th National Audit Project (NAP5) on accidental awareness during general anaesthesia (AAGA). Incidences were estimated using reports of accidental awareness as the numerator, and a parallel national anaesthetic activity survey to provide denominator data. The incidence of certain/probable and possible accidental awareness cases was ~1:19,600 anaesthetics (95% confidence interval 1:16,700-23,450). However, there was considerable variation across subtypes of techniques or subspecialities. The incidence with neuromuscular block (NMB) was ~1:8200 (1:7030-9700), and without, it was ~1:135,900 (1:78,600-299,000). The cases of AAGA reported to NAP5 were overwhelmingly cases of unintended awareness during NMB. The incidence of accidental awareness during Caesarean section was ~1:670 (1:380-1300). Two-thirds (82, 66%) of cases of accidental awareness experiences arose in the dynamic phases of anaesthesia, namely induction of and emergence from anaesthesia. During induction of anaesthesia, contributory factors included: use of thiopental, rapid sequence induction, obesity, difficult airway management, NMB, and interruptions of anaesthetic delivery during movement from anaesthetic room to theatre. During emergence from anaesthesia, residual paralysis was perceived by patients as accidental awareness, and commonly related to a failure to ensure full return of motor capacity. One-third (43, 33%) of accidental awareness events arose during the maintenance phase of anaesthesia, mostly due to problems at induction or towards the end of anaesthesia. Factors increasing the risk of accidental awareness included: female sex, age (younger adults, but not children), obesity, anaesthetist seniority (junior trainees), previous awareness, out-of-hours operating, emergencies, type of surgery (obstetric, cardiac, thoracic), and use of NMB. The following factors were not risk factors for accidental awareness: ASA physical status, race, and use or omission of nitrous oxide. We recommend that an anaesthetic checklist, to be an integral part of the World Health Organization Safer Surgery checklist, is introduced as an aid to preventing accidental awareness. This paper is a shortened version describing the main findings from NAP5--the full report can be found at http://www.nationalauditprojects.org.uk/NAP5_home.
我们呈现了第五次国家麻醉项目（NAP5）关于全身麻醉期间意外意识的主要发现。发病率是通过将意外意识报告作为分子，以及并行的全国麻醉活动调查来提供分母数据来估计的。某些/可能和可能的意外意识病例的发病率约为每 19600 例麻醉 1 例（95%置信区间为 16700-23450 例）。然而，不同技术或亚专业的发病率存在很大差异。有神经肌肉阻滞（NMB）的发病率约为每 8200 例 1 例（7030-9700 例），没有 NMB 的发病率约为每 135900 例 1 例（78600-299000 例）。向 NAP5 报告的 AAGA 病例绝大多数是 NMB 期间意外意识的病例。剖宫产期间意外意识的发病率约为每 670 例 1 例（380-1300 例）。三分之二（82，66%）的意外意识体验病例发生在麻醉的动态阶段，即麻醉诱导和苏醒。在麻醉诱导期间，促成因素包括：使用硫喷妥钠、快速序贯诱导、肥胖、气道管理困难、NMB 以及在从麻醉室到手术室的移动过程中麻醉输送中断。在麻醉苏醒期间，患者将残留的瘫痪视为意外意识，并通常与未能确保运动能力完全恢复有关。三分之一（43，33%）的意外意识事件发生在麻醉维持阶段，主要是由于诱导或麻醉接近尾声时出现问题。增加意外意识风险的因素包括：女性、年龄（年轻成年人，但不包括儿童）、肥胖、麻醉师的资历（初级培训生）、以前的意识、非工作时间手术、紧急情况、手术类型（产科、心脏、胸科）以及 NMB 的使用。以下因素不是意外意识的危险因素：ASA 身体状况、种族以及使用或不使用笑气。我们建议引入麻醉检查表，作为世界卫生组织安全手术检查表的一个组成部分，作为预防意外意识的辅助手段。本文是描述 NAP5 主要发现的简化版本--完整报告可在 http://www.nationalauditprojects.org.uk/NAP5_home 找到。
