Individual pharmacometric analysis for sugammadex reversal and re-administration of neuromuscular blockade

Sugammadex is an innovative reversal agent for neuromuscular blockade (NMB) induced by rocuronium. Although there is a case that re-paralysis is necessary after sugammadex administration, limited reports can be found on the sugammadex dosage for reversal from profound paralysis after induction and immediate re-paralysis following such reversal in detail. We experienced a case in which NMB reversal was required in a short period after paralysis for induction due to the discovery of anisocoria. We successfully re-induced general anesthesia with tracheal intubation soon after. To examine the validity of the dosing, we performed a pharmacometric analysis. A pharmacokinetic-pharmacodynamic model was developed for the patient based on a published pharmacokinetic-pharmacodynamic model for rocuronium and sugammadex. The developed model appropriately describes the train of four ratio observed. In this case, the dose of approximately 8 mg/kg sugammadex but not the conventional dose of 16 mg/kg would be enough for immediate reversal after induction. For the re-paralysis 30 min after NMB reversal, not 1.4 mg/kg but 2.2 mg/kg rocuronium was an adequate dose. Taking individual differences including given dose and time intervals in consideration, NMB monitoring should be used to determine the necessary dose of rocuronium and sugammadex in such situations.