METHODS: This single-center, randomized, double-blind, 2 parallel-arms, noninferiority study comprised 50 patients undergoing general anesthesia with propofol, sevoflurane, fentanyl, and pipecuronium. Neuromuscular monitoring was performed with acceleromyography (TOF-Watch SX). Noninferiority margin was specified beforehand as an increase in reversal time of no >10% (corresponding to 1 minute for the primary outcome). When the block spontaneously recovered to posttetanic count 1, the patients randomly received sugammadex 2 or 4 mg/kg, and the time from the injection to the train-of-four (TOF) ratio of 1.0 was measured. Primary outcome was the time to achieve the normalized TOF ratio of 0.9 in a particular patient. Residual or recurrent postoperative NMB was additional end point.
RESULTS: Each patient recovered to the normalized TOF ratio of 0.9. In the 2 mg/kg group, reversal time was 1.73 ± 1.03 minutes (95% confidence interval [CI], 1.33–2.13; n = 25), and in the 4 mg/kg group, reversal time was 1.42 ± 0.63 minutes (mean ± standard deviation) (95% CI, 1.17–1.67; n = 25). The mean difference in reversal times between the 2 groups was 0.31 minutes (95% CI, −0.18 to 0.8), and the upper limit of CI was below the noninferiority margin of 1 minute. Postoperative block did not occur.
CONCLUSIONS: The effect of sugammadex 2 mg/kg was noninferior to that of 4 mg/kg in reversing posttetanic count-1 degree pipecuronium block. Sugammadex reversal of deep pipecuronium block appears to be effective.