Intraoperative supraglottic airway device, anesthetic, and mechanical factors associated with acute postoperative sore throat in elective tympanoplasty: a retrospective cohort study.

backgroundElective tympanoplasty often uses supraglottic airway devices, such as the laryngeal mask airway (LMA), to ensure smooth emergence from anesthesia. However, LMA-associated postoperative sore throat (POST) remains prevalent. Lateral head rotation during surgery alters LMA intracuff pressure (CP), but the relationship between these pressure changes and POST remains unclear. We aimed to investigate the associations of LMA characteristics, anesthetic management, and position-induced dynamic CP variations with acute POST.

methodsThis retrospective cohort study included 1,363 adult patients undergoing elective tympanoplasty with LMAs. The primary outcome was acute incident POST (visual analog scale [VAS] scores > 0) within 30 min after surgery, and the secondary outcome was POST severity (VAS scores of 0, 1-3, and ≥ 4). Multivariate regression models were used to analyze potential associations with POST. Spline, threshold, and interaction analyses were used to explore non-linear relationships and evaluate the modifying effects of anesthesia duration on CP changes.

resultsThe overall incidence of acute POST was 39.6% (470 mild and 70 moderate-to-severe POST). Tuoren LMA (vs. Flexible LMA), multiple insertion attempts (≥ 3), and elevated baseline supine CP had strong associations with increased risk of incident POST. Non-linear associations with POST incidence were observed for anesthesia duration, position-induced absolute CP change, and relative CP change. Furthermore, anesthesia duration and absolute CP change showed a significant interaction (P = 0.037), with a minor position-induced CP change (-0.52 to 5.79 cmH₂O) associated with a higher risk of acute POST in procedures lasting ≥ 1.3 h (OR: 1.146, 95% CI: 1.041-1.261), but not in shorter surgeries. Similar results were also observed for POST severity, particularly mild POST.

conclusionThis study demonstrated that specific LMA brands, repeated insertions, and elevated baseline CP were significantly associated with acute POST in elective tympanoplasty, and found that a minor position-induced CP change was associated with increased POST risk when anesthesia duration was prolonged. Future prospective trials are warranted to explore the potential complex relationships between supine CP, position-induced CP changes, and anesthesia duration and to assess the clinical need for continuously regulating LMA cuff pressure after head rotation during prolonged otologic surgeries to optimize postoperative recovery.