Residual Neuromuscular Blockade at Extubation: A Randomized Comparison of Sugammadex and Neostigmine Reversal of Rocuronium-Induced Blockade in Patients Undergoing Abdominal Surgery

Background: Residual neuromuscular blockade (NMB) is associated with increased risk of post-operative critical respiratory events. We compared incidence of residual NMB at tracheal extubation after reversal of rocuroniuminduced NMB with sugammadex versus neostigmine. Methods: Adult patients of American Society of Anesthesiologists Class 1-3, scheduled to undergo open abdominal surgery were included. Patients were randomized to receive sugammadex 4.0 mg/kg at ≥1-2 posttetanic counts after last rocuronium dose, or neostigmine 50mg/kg + glycopyrrolate 10mg/kg, according to usual care practices at each institution. Neuromuscular function was assessed using TOF-Watch® SX. Anesthesiologists were blinded to the TOF-Watch recording, except to ask the TOF-Watch operator whether ≥1 PTC had been reached before administering reversal. Use of a peripheral nerve stimulator was permitted. Clinical criteria defined by the institution were used to determine when to perform extubation. Primary efficacy variable was incidence of residual NMB (train-of-four [TOF] ratio <0.9) at extubation. Safety parameters were assessed by a blinded safety assessor. Results: The intent-to-treat group comprised 97 patients (sugammadex, n=51; neostigmine, n=46). Among patients with valid TOF data, a TOF ratio of ≥0.9 was reached at or before extubation in 48 of 50 (96.0%) sugammadex and 17 of 43 (39.5%) neostigmine patients (P<0.0001). One sugammadex (2.0%) and 15 neostigmine patients (34.9%) were extubated at TOF ratios ≤0.7. Median (95% CI) time from study drug administration to recovery to a TOF ratio ≥0.9 was 2.0 (1.8-2.5) minutes for sugammadex (n=49) versus 8.0 (3.8-16.5) minutes for neostigmine (n=18) (P<0.0001). Safety was comparable between groups, with no clinical evidence of recurrence of NMB. Conclusions: Significantly more sugammadex-treated patients recovered to a TOF ratio ≥0.9 at extubation and did so significantly faster than neostigmine-treated patients. This study confirms that sugammadex is more effective than neostigmine in reducing potential for residual blockade in the absence of objective NMB monitoring.