Reversal of neuromuscular blockade with sugammadex based on the residual amount of rocuronium in the body using pharmacokinetic simulation: A single-centre observational study.

BACKGROUND: The relationship between the residual amount of rocuronium and the dose of sugammadex required to reverse neuromuscular blockade (NMB) remains unclear. OBJECTIVES: To determine the required dose of sugammadex based on the estimated residual rocuronium in the body using pharmacokinetic simulation and evaluate the reversal of NMB using sugammadex. DESIGN: Observational study. SETTING: Single-centre, randomised, controlled, four-group, single-blind study conducted at Osaka University Hospital, Japan. PATIENTS: Patients without cardiac, hepatic, renal or neuromuscular disorders scheduled for elective surgery. MAIN OUTCOME MEASURES: For induction, 0.6 mg kg -1 rocuronium was administered. During maintenance, the effect site concentration of rocuronium was maintained at greater than 1 μg ml -1 . The residual amount of rocuronium in the body was calculated postoperatively through pharmacokinetic simulation. Considering the ratio of sugammadex to rocuronium molecules, patients were divided into four groups based on sugammadex dose: control (2 mg kg -1 ), and four, six and eight times the residual amount of rocuronium. Sugammadex was administered shortly after surgery, and the recovery time from administration of sugammadex to the train-of-four (TOF) ratio of 0.9 was recorded. RESULTS: Overall, 123 patients were analysed and successfully extubated, and no signs of recurarisation were observed. Regardless of the sugammadex dose (7.57 ± 2.35 vs. 4.08 ± 0.16 vs. 6.01 ± 0.19 vs. 8.00 ± 0.23 mg kg -1 , P  < 0.01), no significant differences in recovery times were observed among the groups (142 ± 74 vs. 161 ± 98 vs. 152 ± 82 vs. 120 ± 49 s, P  = 0.21). CONCLUSION: Based on pharmacokinetic simulation, all patients successfully recovered from NMB using rocuronium, and excellent recovery profiles were achieved.