Effect-Site Concentration of Rocuronium at the Time of Recovery and Risk of Recurarization in the Presence of Antagonism of Neuromuscular Block by Sugammadex

This single-center prospective study with 50 participants was conducted using train-of-four val-ues obtained intraoperatively by neuromuscular monitoring and pharmacokinetics-pharmacodynam-ics（PK-PD）modeling for the rocuronium-sugammadex complex. Individual changes in the effect-site concentration of free rocuronium after administration and the effect-site concentrations of rocuronium at the time of complete recovery（Ce_r）were calculated using the model developed by Kleijn et al. When sugammadex was administered at the recommended dose stated in the package insert, me-dian Ce_r was 0.43μg/mL（interquartile range, 0.29-0.62μg/mL）. The effect-site concentration of rocuronium remained below the Ce_r value determined in each case, and none of the participants had symptoms suggestive of residual neuromuscular block or recurarization. The PK-PD model appears to be useful for predicting free rocuronium concentrations.