We thank Yang et al. [1] for their interest in our article [2] and for highlighting the difficulties of diagnosing peri-operative anaphylaxis in real time.

The principal aim of this algorithm is to prevent respiratory or cardiovascular deterioration, cardiac arrest and death by promoting early effective treatment, which includes the early use of intravenous adrenaline irrespective of diagnostic uncertainty [3]. Peri-operative anaphylaxis is a diagnostic challenge with a wide range of differential diagnoses. In the UK National Audit Project (NAP6) audit of peri-operative anaphylaxis, 51% of reported cases were not anaphylaxis on review [4], but it is important that attempts to increase diagnostic certainty do not delay treatment. Minimum monitoring standards mandate the use of end-tidal carbon dioxide (ETCO₂) monitoring using waveform capnography [5]. A decline in ETCO₂ is one of several physiological changes that can occur with anaphylaxis as well as any low cardiac output state or with bronchospasm. The use of derived single ETCO₂ cut-off values on an individual patient basis is unlikely to be helpful and we contend that there is insufficient evidence to propose that it is an accurate diagnostic marker of peri-operative anaphylaxis, a conclusion supported by the limited literature [6, 7]. Before ETCO₂ monitoring is considered for inclusion in diagnosing peri-operative anaphylaxis, larger prospective studies are required to provide validation across broader cohorts of patients with confirmed diagnoses of anaphylaxis.

We agree that early administration of intravenous adrenaline, titrated to response is essential to reducing morbidity and mortality in anaphylaxis. End-tidal carbon dioxide monitoring may contribute, along with other parameters, to the evolving clinical picture and guide the titration of adrenaline. It is acknowledged that there is a risk of cardiovascular complications, including Takotsubo cardiomyopathy, associated with adrenaline administration. Nevertheless, in the peri-operative setting patients are closely monitored and under the care of an anaesthetist, which mitigates this risk. Studies show that the use of intravenous adrenaline, particularly as a low-dose infusion as recommended in the RCUK peri-operative algorithm, facilitates more rapid improvement, enables closer titration of doses to effect and results in a lower dose of adrenaline being required overall [8, 9].

The maxim of the RCUK peri-operative algorithm is ‘if in doubt treat’!

我们感谢杨等人。 [ 1 ] 感谢他们对我们的文章 [ 2 ] 的兴趣，并强调了实时诊断围手术期过敏反应的困难。

该算法的主要目的是通过促进早期有效治疗来预防呼吸或心血管恶化、心脏骤停和死亡，其中包括早期使用静脉注射肾上腺素，无论诊断不确定性如何[ 3 ]。围手术期过敏反应是一项诊断挑战，需要进行多种鉴别诊断。在英国国家审计项目 (NAP6) 对围手术期过敏反应的审计中，51% 的报告病例在审查时并非过敏反应 [ 4 ]，但重要的是，尝试提高诊断确定性不会延误治疗。最低监测标准要求使用波形二氧化碳图进行呼气末二氧化碳 (ETCO ₂ ) 监测 [ 5 ]。 ETCO ₂下降是过敏反应以及任何低心输出量状态或支气管痉挛可能发生的几种生理变化之一。在个体患者基础上使用派生的单一 ETCO ₂临界值不太可能有帮助，我们认为没有足够的证据表明它是围手术期过敏反应的准确诊断标志物，这一结论得到了有限的支持。文献[ 6, 7 ]。在考虑将 ETCO ₂监测纳入围手术期过敏反应的诊断之前，需要进行更大规模的前瞻性研究，以在更广泛的已确诊过敏反应的患者群体中提供验证。

我们一致认为，早期静脉注射肾上腺素并根据反应滴定对于降低过敏反应的发病率和死亡率至关重要。潮气末二氧化碳监测可能与其他参数一起有助于不断变化的临床情况并指导肾上腺素的滴定。人们承认，与肾上腺素给药相关的是存在心血管并发症的风险，包括章鱼壶心肌病。然而，在围手术期，患者受到密切监测并接受麻醉师的护理，从而降低了这种风险。研究表明，使用静脉注射肾上腺素，尤其是 RCUK 围手术期算法中推荐的低剂量输注，有助于更快速地改善，能够更接近地调整剂量以达到效果，并导致总体上需要较低剂量的肾上腺素。8、9 ]。

RCUK 围手术期算法的格言是“如有疑问，请治疗”！