We thank Dr Chen et al. for their comments on our article on the effect of nociception level-guided anaesthesia on pain levels and opioid consumption in the post-anaesthesia care unit [1, 2]. Based on our meta-analysis, they conducted a trial sequential analysis to draw even deeper insights from previous studies. They showed that the current literature is not sufficient to conclusively assess the evidence. This important addendum strengthens our statement that, although there are currently studies that nociception level index-guided anaesthesia may reduce postoperative pain, they are not robust enough to recommend its general use.

We strongly support the call for further research. However, it is also important to consider which population and procedures are included. It is possible that the nociception level index could be more useful in vulnerable patient groups (e.g. patients with chronic pain, chronic opioid use or anxiety) and interventions associated with severe postoperative pain. It is also important to take other factors into account in future studies. Does nociception level index-guided anaesthesia reduce the incidence of analgesic-induced adverse effects, such as postoperative nausea or cognitive deficit? How long would a potential difference in pain scores last? Is there a difference in chronic postoperative pain?

In summary, the work of Chen et al. confirms our statement that we currently know too little about nociception level index-guided anaesthesia but that the current evidence raises interesting questions.

我们感谢陈博士等人。感谢他们对我们关于伤害感受水平引导麻醉对麻醉后护理室中疼痛水平和阿片类药物消耗的影响的文章的评论 [ 1, 2 ]。根据我们的荟萃分析，他们进行了试验序贯分析，以从之前的研究中得出更深入的见解。他们表明，当前的文献不足以最终评估证据。这个重要的附录强化了我们的声明，即尽管目前有研究表明伤害感受水平指数引导的麻醉可能会减轻术后疼痛，但它们还不足以推荐其普遍使用。

我们强烈支持进一步研究的呼吁。然而，考虑包括哪些人群和程序也很重要。伤害感受水平指数可能对弱势患者群体（例如患有慢性疼痛、长期使用阿片类药物或焦虑的患者）以及与术后严重疼痛相关的干预措施更有用。在未来的研究中考虑其他因素也很重要。伤害感受水平指数引导麻醉是否可以降低镇痛药引起的不良反应（例如术后恶心或认知缺陷）的发生率？疼痛评分的潜在差异会持续多久？慢性术后疼痛有区别吗？

总之，陈等人的工作。证实了我们的说法，即我们目前对伤害感受水平指数引导麻醉知之甚少，但当前的证据提出了有趣的问题。