Dose-dependent effects of esketamine on the prevention of propofol-induced injection pain: a randomized controlled trial
BMC Anesthesiology January 17, 2026 Danyun Fu, Yilei Shen, Hongyan Xiao et al.
A double-blind randomized controlled trial tested whether a low dose of esketamine given before propofol reduces injection pain during anesthesia induction. The 0.3 mg/kg dose of esketamine reduced the incidence of pain to 9%, compared to 71% with saline and 32% with lidocaine. Both 0.15 and 0.3 mg/kg doses also helped maintain stable blood pressure and heart rate. No increase in side effects was seen. The authors recommend 0.3 mg/kg esketamine as the preferred pretreatment dose for preventing propofol-induced injection pain and ensuring hemodynamic stability.