This is an estimation study, prospectively evaluating the incidence of postoperative residual neuromuscular blockade (PRNB) when a best practice protocol is implemented for a cohort of abdominal surgery and orthopedic surgery patients. The protocol is developed within the constraint of subjective monitoring, quantitative monitoring is not used, and use of rocuronium for paralysis and either neostigmine or sugammadex for reversal. The primary outcome is the incidence of PRNB on arrival to the post-anesthesia care unit, defined as a train-of-four ration <0.9.

This study estimates the incidence of postoperative residual neuromuscular block when rocuronium neuromuscular block is managed by protocol for qualitative monitoring and reversal with neostigmine or sugammadex. The study is an extension of the recently published study by Thilen and co-workers which evaluated a protocol which used neostigmine as the sole reversal agent (doi: 10.1016/j.bja.2018.03.029). It demonstrated that use of a protocol was associated with a reduced incidence of severe residual paralysis, defined as normalized train-of-four (TOF) ratio <0.7 at time of tracheal extubation. It was also associated with a highly significant reduction in PRNB as defined for several secondary outcomes, including non-normalized (i.e. raw) TOF-ratio <0.9 at time of arrival to the post-anesthesia care unit (PACU).

The current study does not include a control group, only an intervention group. The investigators hypothesize that PRNB can be prevented by adhering to a protocol which incorporates several current recommendations by experts. Importantly, the protocol preserves a role for neostigmine when the pre-reversal assessment indicates that spontaneous recovery has progressed to a so-called minimal block which is defined as the subjective absence of fade in the adductor pollicis TOF response. The investigators will study only abdominal surgery and orthopedic surgery patients. The primary outcome is incidence of PRNB, defined as TOF-ratio <0.9 on arrival to the PACU. The investigators plan to enroll 120 patients, and if no more than one patient has PRNB, the upper bound for the 95% confidence interval will be less than 5%.

Inclusion Criteria: Adult 18 years old or older, Will undergo open or laparoscopic abdominal surgery or orthopedic surgery expected to last <6 hours at Harborview or Univ of Wash Med Ctr, Have American Society of Anesthesiologists physical status I-III, scheduled to have general anesthesia with at least 1 dose of nondepolarizing neuromuscular blocking drug for endotracheal intubation or intraoperative neuromuscular blockade.

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Exclusion Criteria: Allergy to neuromuscular blocking drugs, patients with neuromuscular disease (myasthenia gravis or muscular dystrophy), pregnant or lactating women, non-English speaking.

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We approached 201 patients who provided signed informed consent. A total of 163 patients completed the study and were included in the primary per-protocol analysis.

1 day: Day of surgery through recovery in PACU.