Potency estimation of sugammadex for the reversal of moderate rocuronium-induced neuromuscular block: a non-randomized dose–response study

There is no report investigating the precise potency of sugammadex for antagonizing various intensities of rocuronium-induced neuromuscular block. The aim of this study was to evaluate the ED95 of reversibility of sugammadex and reveal the safety factor of 2 mg/kg of sugammadex for moderate rocuronium-induced neuromuscular block. Fifteen patients were enrolled in this study. After induction of anesthesia, we recorded the adductor pollicis muscle response to ulnar nerve stimulation using acceleromyography. All patients received 0.6 mg/kg rocuronium. When the first twitch (T1) of the train-of-four (TOF) response reappeared, rocuronium infusion was commenced to maintain T1 at 10% of the control. After the surgery was completed and infusion of rocuronium was stopped, patients were given sugammadex by a cumulative dose technique. The effective doses of sugammadex that led to recovery of the amplitude of T1 and the TOF ratio by 95% (ED95) were calculated from the regression lines of least-squares regression analysis. The mean ED95 of sugammadex for recovery of T1 and the TOF ratio from rocuronium-induced moderate neuromuscular block was 1.34 (0.24) and 1.14 (0.24) mg/kg, respectively. The ED95 of sugammadex for the recovery of T1 was significantly greater than that for the TOF ratio. However, a sugammadex dose of 2 mg/kg is equivalent to about 1.5 times the ED95 of sugammadex for reversal of moderate rocuronium-induced block, indicating its safety margin.