Effects of different doses of esketamine combined with propofol on gastrointestinal endoscopy in elderly patients

Propofol alone for painless gastroscopy/colonoscopy in elderly patients causes frequent movement and respiratory depression due to poor analgesia. Esketamine, the only intravenous anesthetic with analgesic properties, may allow safer co-sedation. To identify the optimal esketamine dose combined with propofol for elderly patients undergoing gastroenterological endoscopy. 240 outpatients ≥60 yr were randomized to E1 group (esketamine 0.1 mg/kg), E2 group (esketamine 0.2 mg/kg) or E3 group (esketamine 0.3 mg/kg) (n=80 each). After i.v. esketamine 0.1, 0.2, or 0.3 mg/kg, respectively, propofol 2 mg/kg was given. mean arterial pressure (MAP), heart rate (HR), pulse oxygen saturation (SpO₂), additional propofol doses, total propofol and esketamine consumption, recovery time, pain scores, and adverse events were recorded at ten predefined time-points. Additional propofol boluses and total propofol dose were lower in E2 and E3 than E1 (P<0.001). Respiratory depression was higher in E3 vs. E1 and E2 (10% vs. 1.25% and 2.5%, P<0.05). MAP at T2 was unchanged in E2 but decreased in E1 and E3 (P<0.05); HR at T2 rose only in E2 (P<0.05). Recovery time, pain scores, and post-procedure adverse events did not differ among groups. Esketamine 0.2 mg/kg combined with propofol provides effective sedation and analgesia, maintains hemodynamic stability, reduces movement and propofol requirement, and does not increase respiratory depression in elderly patients undergoing painless endoscopy.