Abstract
BACKGROUND: Catheter-related bladder discomfort (CRBD) is associated with anxiety, pain, and an increased risk of perioperative complications. Esketamine, which exhibits analgesic and anticholinergic properties, may offer therapeutic benefits in this context. This study aims to evaluate the effects of varying sub-anesthetic doses of esketamine on the incidence and severity of CRBD following ureteroscopic lithotripsy. METHODS: A total of 168 patients were randomly assigned to three groups: Esk15 (0.15 mg/kg esketamine), Esk25 (0.25 mg/kg esketamine), and a placebo group (2 mL saline). The primary outcome was the incidence of moderate-to-severe CRBD at 0 h postoperatively. Secondary outcomes included the incidence and severity of CRBD at 0, 1, 2, and 6 h postoperatively, esketamine-related adverse reactions, rescue doses of tramadol and metoclopramide, and patient satisfaction assessed at 6 h postoperatively. RESULTS: One hundred sixty-six enrolled patients completed the study (Esk15: n = 55; Esk25: n = 55; placebo: n = 56). The incidence of moderate-to-severe CRBD at 0 h postoperatively was significantly lower in the Esk25 group (9.1%, 5/55; P = 0.001) compared to the placebo group (33.9%, 19/56). At 1 h and 6 h postoperatively, the Esk25 group exhibited a further reduction in moderate-to-severe CRBD incidences compared to placebo (1 h: P = 0.011; 6 h: P = 0.009). Furthermore, the incidences of CRBD at 0 and 1 h postoperatively were significantly lower in group Esk25 compared to placebo group (0 h: P = 0.006; 1 h: P = 0.001). The Esk25 group required significantly fewer tramadol rescue doses than the placebo group (P < 0.001). No significant differences were observed among the groups in metoclopramide use, patient satisfaction, or esketamine-related adverse events. CONCLUSION: Esketamine administered at a dose of 0.25 mg/kg was effective in reducing both the incidence and severity of CRBD, without increasing adverse effects. These findings suggest that a higher sub-anesthetic dose of esketamine may be a viable option for managing CRBD in patients undergoing ureteroscopic lithotripsy. TRIAL REGISTRATION: The trial was registered at the Chinese Clinical Trials Registry ( www.chictr.org.cn , registration number: ChiCTR2300076262, date of registration: 29/09/2023).