We thank Hulst et al. [1] and Levy et al. [2] for their comments on our work [3]. Peri-operative use of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) has gained much attention recently.

We acknowledge the significance of power calculations in trial design to minimise type 2 error. It is essential to recognise, however, that power can be considered adequate with a smaller sample size if the effect size is large [4], as evidenced by our observed (clinically significant) differences between semaglutide users (40% incidence of increased residual gastric content) and non-users (3%, p < 0.001). For further clarification, we performed a post hoc power analysis based on our studied patients and parameter estimates. For an effect size of 0.7 based on the presence of increased residual gastric content in 43/107 semaglutide users and 3/113 non-users, and a significance level of 5%, using a χ² test, we achieved a critical χ² = 11.07 and a power (1-β error probability) > 0.9.

Our exclusion criteria accounted for conditions known to affect gastric emptying; hence our observed increased residual gastric content can be attributed primarily to semaglutide use. These exclusions strengthen, rather than limit, our findings' applicability. While we did not study patients with diabetes, we agree that future guidelines should focus on peri-operative management of GLP-1 RAs based on their primary use (weight loss vs. diabetes).

As for other classes of medications that can delay gastric emptying, it is impossible to call for revised societal guidelines for their peri-operative use when such guidelines do not exist. The impaired gastric emptying from these drugs has not been considered sufficiently relevant (unlike that induced by GLP-1 RAs) to warrant the attention of medical or anaesthesia societies to create specific guidelines.

Recently, several case reports have been published linking peri-operative GLP-1 RA use with bronchoaspiration and/or near misses [5]. Although anecdotal, it would be imprudent to disregard these reports and the growing body of evidence demonstrating a correlation between GLP-1 RA use and increased peri-operative residual gastric content [3, 6] as “lacking evidence” [2]. The recent development of multi-societal guidelines for the peri-operative management of GLP-1 RA [7] reflects this linkage.

Due to constraints inherent to our institutional protocol, we did not evaluate periods of discontinuation longer than 10 days and, consequently, were unable to make recommendations beyond this timeframe. Nevertheless, based on our findings (and other recent reports [6]), it does appear that 1-week pre-operative discontinuation suggested by the American Society of Anesthesiologists and other medical societies [7] may be insufficient to ensure an empty stomach. Indeed, while previous reports suggesting a 2–3 week semaglutide interruption pre-operatively were based primarily on pharmacologic principles, a recent study by our group suggests that similar intervals are required to reduce/normalise gastric content in semaglutide users [6]. While we acknowledge the limitations of recent reports, they align; therefore, given the catastrophic consequences of bronchoaspiration, it would be prudent to err on the side of caution until more definitive evidence emerges. Additionally, while peri-operative hyperglycaemia resulting from GLP-1 RA interruption remains a subject of debate [8], this can be mitigated by bridging regimens with less/no effect on gastric emptying. Notably, patients with diabetes on GLP-1 RAsare often already on insulin therapy in which case they can simply follow their baseline sliding scale, without the need for further delays (e.g. diabetologist consultation) as suggested by Levy et al. [2].

Hulst et al. suggested that gastric ultrasound has limited broad application. It is up to clinicians to decide whether this non-invasive tool, which has a rapid learning curve, should be part of their practice. In our cohort, gastric ultrasound prevented unnecessary surgical cancellations in semaglutide users. The peri-operative applicability of gastric ultrasound, particularly in the context of GLP-1 RA use, has gained attention recently and has been highlighted by anaesthesia and medical societies worldwide [7].

We recognise that ongoing digestive symptoms and semaglutide dosage/therapy duration may impact gastric emptying. Although we did not examine these variables, our study is the largest prospective cohort assessed via peri-operative bedside gastric ultrasound to date. Thus, despite its limitations, our findings are clinically significant.

我们感谢 Hulst 等人 [1] 和 Levy 等人 [2] 对我们工作的评论[3]。胰高血糖素样肽-1 受体激动剂 （GLP-1 RAs） 的围手术期使用最近受到广泛关注。

我们承认功效计算在试验设计中的重要性，以最大限度地减少 2 类错误。然而，必须认识到，如果效应量很大 [4]，则可以认为样本量较小时有足够的功效 [4]，正如我们观察到的 semaglutide 使用者（残余胃内容增加的发生率增加 40%）和非使用者（3%，p < 0.001）之间的（临床显着）差异所证明。为了进一步澄清，我们根据我们研究的患者和参数估计进行了事后功效分析。基于 43/107 索马鲁肽使用者和 3/113 非使用者中残余胃内容增加的效应量为 0.7，显著性水平为 5%，使用 χ² 检验，我们获得了临界 χ² = 11.07 和功效（1-β 误差概率）> 0.9。

我们的排除标准考虑了已知影响胃排空的情况;因此，我们观察到的残余胃内容物增加主要归因于索马鲁肽的使用。这些排除加强了而不是限制了我们研究结果的适用性。虽然我们没有研究糖尿病患者，但我们同意未来的指南应根据 GLP-1 RAs 的主要用途（减肥与糖尿病）关注 GLP-1 RAs 的围手术期管理。

至于其他可以延迟胃排空的药物类别，当此类指南不存在时，就不可能要求修订其围手术期使用的社会指南。这些药物导致的胃排空受损被认为不够相关（与 GLP-1 RA 诱导的不同），因此医学或麻醉学会没有得到关注以制定具体指南。

最近，已发表几篇病例报告将围手术期 GLP-1 RA 的使用与支气管抽吸和/或未遂事故联系起来 [5]。尽管是轶事，但忽视这些报告和越来越多的证据表明 GLP-1 RA 的使用与围手术期残余胃内容物增加之间存在相关性 [3， 6] 是轻率的，因为“缺乏证据”[2]。最近制定的 GLP-1 RA 围手术期管理的多社会指南 [7] 反映了这种联系。

由于我们机构方案固有的限制，我们没有评估超过 10 天的停药时间，因此无法在此时间范围之后提出建议。然而，根据我们的研究结果（和其他最近的报告[6]），美国麻醉医师协会和其他医学会[7]建议的术前1周停药似乎确实不足以确保空腹。事实上，虽然之前的报告表明术前 2-3 周的 semaglutide 中断主要基于药理学原理，但我们小组最近的一项研究表明，需要类似的间隔来减少/正常化 semaglutide 使用者的胃内容物 [6]。虽然我们承认最近报告的局限性，但它们是一致的;因此，考虑到支气管抽吸的灾难性后果，在出现更明确的证据之前，谨慎行事是明智的。此外，虽然 GLP-1 RA 中断导致的围手术期高血糖仍是一个争论的话题 [8]，但这可以通过对胃排空影响较小/无影响的桥接方案来缓解。值得注意的是，接受 GLP-1 RAs的糖尿病患者通常已经在接受胰岛素治疗，在这种情况下，他们可以简单地遵循基线滑动量表，而无需进一步延迟（例如糖尿病专家咨询），如 Levy 等人 [2]。

Hulst 等人认为，胃超声的广泛应用有限。由临床医生决定这种具有快速学习曲线的非侵入性工具是否应该成为他们实践的一部分。在我们的队列中，胃超声防止了 semaglutide 使用者不必要的手术取消。胃超声的围手术期适用性，特别是在使用 GLP-1 RA 的情况下，最近受到了关注，并受到全世界麻醉和医学会的重视 [7]。

我们认识到，持续的消化系统症状和索马鲁肽剂量/治疗持续时间可能会影响胃排空。虽然我们没有检查这些变量，但我们的研究是迄今为止通过围手术期床边胃超声评估的最大前瞻性队列。因此，尽管存在局限性，但我们的研究结果具有临床意义。