Abstract
OBJECTIVES: To investigate the impact of varying neuromuscular blockade (NMB) depths on the success of i-gel laryngeal mask airway (LMA) insertion and to examine determinants of postoperative sore throat (POST) in adult patients under general anesthesia. METHODS: This retrospective case-control study included 140 adults who underwent general anesthesia with i-gel LMA from November 2023 to July 2024. Subjects were categorized into four groups based on neuromuscular blockade depth: deep (Group A), moderate (Group B), shallow (Group C), and minimal (Group D), as measured by Train-of-Four ratio. We assessed baseline characteristics, i-gel insertion success rates, complications, and POST severity at multiple intervals after surgery. Factors affecting POST were analyzed using correlation analysis and logistic regression models. RESULTS: Moderate NMB (Group B) demonstrated significantly higher first-attempt i-gel insertion success (91.43%) compared to deep (62.86%), shallow (60.00%), and minimal (60.00%) NMB groups (P < 0.01). No significant differences in complication rates were observed among groups. POST severity at 0.5 hours was significantly lower in Group B but equalized across all groups at 6 and 24 hours. Multivariate analysis identified smoking history (OR = 0.258, 95% CI: 0.116-0.574, P < 0.001) and blood sputum presence (OR = 0.337, 95% CI: 0.099-1.148, P = 0.082) as inversely associated with POST, while higher ASA classification (OR = 0.421, 95% CI: 0.185-0.956, P = 0.039) and longer placement time (OR = 0.174, 95% CI: 0.060-0.500, P = 0.001) were significant predictors. CONCLUSION: This study demonstrates that moderate muscle relaxation significantly enhances i-gel LMA insertion success and reduces early POST severity. The identification of protective factors against POST highlights the importance of developing personalized perioperative strategies to improve patient comfort and airway management outcomes.