Study Objective:

This study aims to evaluate the incidence, severity, and risk factors of sugammadex-induced mouth clenching during neuromuscular blockade (NMB) reversal in adult surgical patients.

Study Design:

This prospective, randomized, double-blind, controlled clinical trial enrolls adult patients (ASA physical status I-II, aged 19-70 years) undergoing elective surgery under general anesthesia with rocuronium. Patients will be randomized into four groups to receive either sugammadex at doses of 1 mg/kg, 2 mg/kg, or 4 mg/kg, or a combination of pyridostigmine and glycopyrrolate.

Primary Outcome:

The primary outcome is the incidence of clenching within 10 minutes after NMB reversal, assessed by clinical observation, masseter EMG, and airway pressure changes, using a novel five-grade severity scale.

Secondary Outcomes:

Secondary outcomes include the severity of clenching, time to TOF ratio ≥0.9, BIS values at clenching onset, complications, and identification of risk factors such as dose, sex, BIS, age, BMI, and rocuronium dose.

Significance:

This study seeks to improve perioperative safety by identifying modifiable risk factors and informing dose adjustments or alternative reversal strategies to prevent sugammadex-induced clenching, particularly in high-risk populations.

This prospective, randomized, double-blind clinical trial aims to investigate the incidence, risk factors, and clinical implications of sugammadex-induced clenching during neuromuscular blockade reversal under general anesthesia. Sugammadex, a selective relaxant binding agent, is widely used for the rapid reversal of rocuronium-induced neuromuscular blockade. However, reports of jaw clenching and masseter muscle contraction following sugammadex administration have raised safety concerns, particularly regarding airway management and patient discomfort during emergence from anesthesia.

A total of 240 adult patients (ASA physical status I-II, aged 19 to 70 years) scheduled for elective surgery under general anesthesia with rocuronium will be enrolled. Participants will be randomly assigned to one of four groups in a 1:1:1:1 ratio: sugammadex 1 mg/kg (S1), 2 mg/kg (S2), 4 mg/kg (S4), or pyridostigmine 0.2 mg/kg with glycopyrrolate 0.01 mg/kg (PG) as the control. Clenching events will be assessed within 10 minutes of drug administration using three criteria: visible jaw clenching, increased masseter electromyographic (EMG) activity (>50 μV for ≥2 seconds), and a rise in airway pressure (>5 cm H₂O). Severity will be graded using a novel five-level classification system.

Secondary outcomes include the severity and timing of clenching, time to train-of-four (TOF) ratio ≥0.9, bispectral index (BIS) value at the time of clenching onset, airway-related complications, and risk factor analysis based on dose, sex, BIS, age, BMI, and total rocuronium dose.

This study hypothesizes a dose-dependent increase in clenching with higher doses of sugammadex, potentially with a higher incidence in female patients and those with higher BIS values at reversal."

Inclusion Criteria:

• Eligible participants are adults aged 19-70 years, American Society of Anesthesiologists (ASA) physical status I-II, undergoing elective surgery under general anesthesia with rocuronium.

Exclusion Criteria:

• Exclusion criteria include neuromuscular disorders, renal impairment (creatinine clearance < 30 mL/min), history of clenching or dental disease, allergy to study drugs, or emergency surgery.

Individual participant data (IPD) that underlie the results reported in this article will be shared, including study protocol, statistical analysis plan, and analytic code.

Beginning 6 months and ending 36 months following article publication.

Researchers who provide a methodologically sound proposal and agree to sign a data access agreement.