Prophylactic Low-Dose Esketamine for Prevention of Intraoperative Penile Erection During Ureteroscopic Surgery Under General Anesthesia: A Randomized, Double-Blind, Placebo-Controlled Trial

Purpose

Intraoperative penile erection (IPE) during ureteroscopic surgery may interrupt surgical procedures and increase the risk of urethral injury. Existing management strategies are largely reactive and frequently require rescue interventions after erection has already developed. Effective prophylactic strategies remain limited. We evaluated whether prophylactic esketamine reduces the incidence of intraoperative penile erection during ureteroscopic surgery under general anesthesia. Patients and methods: This single-center, double-blind, randomized, placebo-controlled trial (Chinese Clinical Trial Registry, ChiCTR2500114505) enrolled 356 adult men (ASA I-II) scheduled for elective ureteroscopic surgery. Patients were randomized 1:1 to receive intravenous esketamine 0.3 mg/kg or saline before anesthetic induction; allocation was concealed, and patients, anesthetists, surgeons, and outcome assessors were blinded. The primary outcome was the incidence of IPE (Porst grade ≥1), assessed at nine predefined intraoperative time points (T0-T8), with rescue treatment for erections of grade ≥2. Secondary outcomes included erection severity, hemodynamic variables, recovery characteristics, and adverse events.