Anesthetic efficacy of two administration regimens of obucaine hydrochloride gel for transnasal fiberoptic laryngoscopy: a single-center retrospective cohort study.

Background: The primary objective of this study was to compare the comprehensive clinical tolerability and procedural performance, including intra-procedural pain, post-procedural pharyngeal discomfort, procedural efficiency, and safety, of nasal-only vs. combined nasopharyngeal anesthesia with obucaine hydrochloride gel for transnasal fiberoptic laryngoscopy (TFL). This study explicitly differentiated comprehensive clinical experience from pure analgesic efficacy, and made no Methods: This single-center retrospective study enrolled patients undergoing first-time TFL between June and December 2025, who were assigned to either nasal-only anesthesia (Group A) or combined nasopharyngeal anesthesia (Group B). 1:1 propensity score matching (PSM) was conducted to balance baseline confounding variables. The primary outcome was the incidence of moderate-to-severe post-procedural pharyngeal discomfort assessed within 2 h of TFL, a composite endpoint reflecting holistic patient experience and procedural feasibility. We explicitly acknowledged that this endpoint includes functional impairments inherent to pharyngeal topicalization and may structurally favor the nasal-only regimen. This endpoint was not designed to measure pure analgesic efficacy. Secondary outcomes included examination duration, operator-assessed procedural difficulty visual analog scale (VAS) score, patient-reported pain VAS score, and adverse events. Results: A total of 950 patients were initially enrolled (470 in Group A, 480 in Group B), and 420 patients per group were included in the final analysis following 1:1 PSM. Baseline characteristics were well-balanced between groups, with all Conclusion: Among relatively healthy outpatients aged 18-60 years undergoing diagnostic-only TFL without anatomical abnormalities or concurrent therapeutic procedures, nasal-only administration of obucaine hydrochloride gel was associated with superior procedural tolerability and shorter objective examination time compared with the nasopharyngeal combined regimen. No significant between-group difference was observed in patient-reported pain intensity, and no major safety signals were detected in this cohort. No conclusion of safety equivalence can be drawn due to the limited sample size and follow-up duration. These findings provide real-world evidence to guide anesthesia regimen selection in this specific outpatient population, and generate hypotheses for future prospective, multicenter studies to confirm these results in broader clinical populations.