Prophylactic Low-Dose Esketamine for Prevention of Intraoperative Penile Erection During Ureteroscopic Surgery Under...

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.

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.

The incidence of IPE was 6.2% (11/178) with esketamine versus 21.9% (39/178) with saline (RR 0.282, 95% CI 0.149-0.533; ARR 15.7%; NNT 6.4; P < 0.001). Porst grades were lower in the esketamine group during disinfection, ureteroscope insertion, and 10 min after surgery commenced, and fewer patients required rescue treatment for clinically significant erection (Porst grade ≥ 2, 4.5% vs 21.3%; P < 0.001). Mean arterial pressure was higher with esketamine intraoperatively (adjusted mean difference 3.49 mmHg), and heart rate was higher, without clinically significant hemodynamic disturbance. Recovery and adverse events did not differ significantly between groups, no hallucinations occurred; postoperative catheter-related bladder discomfort was less severe with esketamine (P < 0.001).

Prophylactic low-dose esketamine was associated with a lower incidence and severity of intraoperative penile erection, without evidence of impaired postoperative recovery. These findings suggest that prophylactic esketamine may be a useful strategy for preventing this perioperative complication, warranting confirmation in larger multicenter trials.