Gastric content and aspiration risk after semaglutide cessation: a reply

We thank Chang for the correspondence [1] regarding our recent publication on gastric ultrasound findings in patients receiving semaglutide [2]. We acknowledge the findings of the meta-analysis by Elkin et al., which reported an association between glucagon-like peptide-1 receptor agonist (GLP-1 RA) exposure and residual gastric contents without showing an increased incidence of pulmonary aspiration [3]. However, it is important to recognise that these conclusions were derived from different datasets. Evidence regarding residual gastric content was based on prospective and retrospective studies, whereas evidence regarding pulmonary aspiration relied exclusively on retrospective analyses. Although these retrospective studies included large patient populations, pulmonary aspiration events were identified primarily via electronic medical records or administrative claims data, which lack detailed peri-operative information. For example, clinicians may have anticipated an increased aspiration risk in patients receiving GLP-1RA therapy and adopted strategies such as rapid sequence induction and intubation, potentially reducing the observed incidence of aspiration. In addition, unreported or undocumented GLP-1 RA use may not be captured reliably in retrospective datasets. In our experience, such off-label use of GLP-1 RA, even including experimental drugs such as retatrutide, occurs not infrequently. Although we agree that the presence of limited solid residual gastric content does not necessarily translate directly into pulmonary aspiration events, residual gastric content remains a clinically relevant finding and is widely considered a surrogate marker of increased aspiration risk in peri-operative practice. In the absence of high-quality prospective aspiration outcome data, the consistent findings of prospective gastric ultrasound studies showing residual gastric content should therefore receive careful consideration and not be readily dismissed based on retrospective data with their inherent limitations. Fortunately, pulmonary aspiration remains a rare event, although this also makes prospective study of this specific outcome challenging. Pending stronger evidence, we advocate a cautious peri-operative approach, including pre-operative gastric ultrasound where expertise and resources are available. Regarding withholding semaglutide, we agree that withholding a single dose does not appear to normalise gastric ultrasound findings. Several previous prospective studies have similarly suggested that withholding periods <14 days may be insufficient [4]. Patients receiving semaglutide and potentially other GLP-1 RA therapies may present with residual solid gastric content despite appropriate fasting and withholding of one dose. Until higher-quality evidence becomes available regarding the relationship between these findings and pulmonary aspiration, consideration should be given to longer withholding intervals and/or the use of gastric ultrasound to individualise peri-operative management.