Postoperative delirium and quality of recovery in older patients undergoing gastrectomy under general anaesthesia with remimazolam vs. propofol

We congratulate Sim et al. on a high-quality, adequately powered randomised trial, which advances the evidence on remimazolam for delirium prevention in older adults undergoing gastrectomy [1]. We hope that clarification of several concerns can enhance the interpretation of the study and guide future research efforts. First, the primary outcome of this trial is influenced by multiple peri-operative factors. Pre-operative anxiety [2] or depression, poor sleep quality, low educational level and a history of prior delirium are established independent risk factors for postoperative delirium [3]. The study did not report whether these baseline characteristics or other documented pre-operative risk factors were balanced between the two groups, which may have introduced confounding effects on incidence. Future research should proactively identify and collect data on these pre-operative factors and either exclude them or adjust for them statistically during the design or analysis phase. Second, the focus of the study on older patients undergoing gastric surgery with general anaesthesia alone has potential limitations. Radical gastrectomy often requires multiple indwelling tubes (e.g. nasogastric, drain, urinary catheter), which can contribute independently to delirium, potentially confounding the results. Even laparoscopic gastrectomy necessitates a significant abdominal incision for tumour resection and gastrointestinal reconstruction, resulting in considerable postoperative pain and a high risk of inadequate analgesia [4], a key postoperative delirium risk factor. While bilateral transversus abdominis plane blocks are used commonly in clinical practice to reduce opioid consumption, minimise postoperative nausea and vomiting, and promote recovery, this study used general anaesthesia alone without regional blocks and relied primarily on oxycodone patient-controlled analgesia for postoperative pain management. This approach may explain the high incidence of postoperative nausea, retching or vomiting (38.2%, 165/432). Finally, haemodynamic stability was defined as a systolic blood pressure > 80 mmHg and a heart rate > 45 beats per minute. This definition did not account for individualised adjustments based on dynamic blood pressure changes and may present potential safety concerns, especially the high prevalence of hypertension (58.4%, 247/423). For instance, before initiating intervention it would be clearly inappropriate to wait for the systolic pressure to fall below 80 mmHg in a patient with a baseline systolic pressure of 160 mmHg. Furthermore, given that intra-operative hypotension may be a risk factor for postoperative delirium [5], we suggest recording and comparing meticulously the use and doses of vasopressor drugs between the two study groups. This detailed documentation will provide a robust reference for future research and clinical practice.