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

ABSTRACT

PURPOSE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.