Reversal of neuromuscular block with neostigmine and sugammadex: a retrospective cohort study in two centers using different types of neuromuscular monitoring

This bicentric retrospective cohort study evaluates reversal of muscle relaxation in real life achieved either by neostigmine or sugammadex in two hospitals using different types of neuromuscular monitoring (acceleromyography and kinemyography). The research question concerns compliance with recommendations. Patients who underwent an abdominal surgery under general anesthesia in the period from January 2017 through December 2020 with a neuromuscular block with rocuronium were included in the study. Data were extracted from the Centricity anesthesia information management system. In total, 2242 patients were assessed: 459 in center 1 (61 having received neostigmine and 398 sugammadex) and 1783 in center 2 (531 and 1252, respectively). Patients' characteristics differed between centers, with more high-risk patients in center 1. The mean train-of-four (TOF) ratio after supramaximal current determination (supramaximal threshold) was higher in center 1 (p < 0.001). Most patients received neostigmine while the TOF ratio was < 40% (68.6% in center 1 and 62.4% in center 2), while extubation was performed while the TOF ratio was > 90% in 61.0% in center 1 and in 32.1% in center 2 (p < 0.001). Patients received sugammadex irrespective of the number of responses to TOF before reversal, and extubation was performed while the TOF ratio was > 90% in 85.0% in center 1 and in 53.6% in center 2 (p < 0.001). No side effect was encountered. Despite guidelines for the TOF ratio before extubation, recommendations were not adequately respected and more vigilance is mandatory. The TOF test before use gave values that were 100% far apart with an underestimation with acceleromyography and an overestimation using kinemyography.