Effect of dexmedetomidine on intraocular pressure in patients undergoing robot-assisted laparoscopic radical prostatectomy under total intravenous anesthesia: A randomized, double blinded placebo controlled clinical trial

Study objective: To study the effects of intraoperative dexmedetomidine on the intraocular pressure (IOP) in patients undergoing robot-assisted laparoscopic radical prostatectomy (RALRP) under propofol-remifentanil anesthesia. Design: Double-blind, randomized controlled trial. Setting: Operating room. Patients: Forty consenting male patients aged 20 to < 80 years with American Society of Anesthesiologists physical status classes I and II. Interventions: The patients were randomly assigned to either dexmedetomidine (DEX) (n = 20) or control (n = 20) group. Anesthesia was induced and maintained using propofol, remifentanil, and rocuronium. In the dexmedetomidine group, dexmedetomidine was administered at 0.4 mu g/kg/h immediately after anesthesia induction until the end of the surgery, whereas normal saline was administered as placebo in the control group. Measurements: IOP was measured using a rebound tonometer. Time points of measuring LOP were as follows: T1: before anesthesia induction, T2: 5 min after intubation, T3: 60 min after placing patient in the Trendelenburg position, T4: 120 min after placing patient in the Trendelenburg position, T5: 180 min after placing patient in the Trendelenburg position, T6: 5 min after placing patient in a horizontal position, T7: 5 min after extubation, and T8: 30 min after extubation. Main results: A linear mixed model analysis demonstrated a significant intergroup difference in LOP over time and during pneumoperitoneum in the steep Trendelenburg position. IOP at T5 was significantly lower in the dexmedetomidine group than in the control group even after post-hoc analysis in the steep Trendelenburg position periods with Bonferroni correction. Conclusions: Dexmedetomidine combined with propofol decreases LOP in the steep Trendelenburg position during RALRP.