Low dose esketamine for gastrointestinal endoscopy: a double-blinded, randomized controlled trial

Background: Propofol and remifentanil are frequently used together for painless therapeutic gastrointestinal (GI) endoscopy. However, this combination can result in respiratory and cardiovascular depression. The use of esketamine has the potential to counteract these adverse effects. This study evaluates the efficacy and safety of low-dose esketamine combined with a fixed dose of propofol-remifentanil sedation during painless therapeutic GI endoscopy. Methods: A total of 400 patients undergoing painless therapeutic GI endoscopy were randomly divided into four groups (n = 100 per group). The control group received propofol and remifentanil, while the other three groups received propofol and remifentanil plus 0.05, 0.10 and 0.15 mg/kg/h esketamine. Throughout the procedure, we recorded hemodynamics, pulse oxygen saturation, somatic responses, adverse event management, emergence delirium and perioperative Mini-Mental State Examination (MMSE) scores. Results: Respiratory interventions were significantly higher in the control groupcompared to three esketamine groups (elevated oxygen flow: 15% vs. 2%, 2% and 4%; mandibular support: 10% vs. 1%, 1% and 3%; mask ventilation: 4% vs. 0%, 0% and 0%). Hypotension and bradycardia occurred more frequently in the control group (hypotension: 13% vs. 3%, 1% and 1%; bradycardia: 15% vs. 5%, 3% and 2%). Although there were no significant differences in gagging among the groups, a reduced response to body movement was documented in patients randomized to esketamine when compared to the control group (1% vs. 13%). No significant changes were observed in MMSE scores in any of the groups. Conclusions: The continuous infusion of small-dose esketamine in addition to propofol-remifentanil sedation could provide efficient and safe sedation for painless therapeutic GI endoscopic procedures. Clinical Trial Registration: The study was registered in the Chinese Clinical Trial Registry (Registration number: ChiCTR2400079866). Date of registration: 15 January 2024.