Table_2_Hyperangulated blades or direct epiglottis lifting to optimize glottis visualization in difficult Macintosh videolaryngoscopy: a non-inferiority analysis of a prospective observational study.DOCX

PurposeIt is unknown if direct epiglottis lifting or conversion to hyperangulated videolaryngoscopes, or even direct epiglottis lifting with hyperangulated videolaryngoscopes, may optimize glottis visualization in situations where Macintosh videolaryngoscopy turns out to be more difficult than expected. This study aims to determine if the percentage of glottic opening (POGO) improvement achieved by direct epiglottis lifting is non-inferior to the one accomplished by a conversion to hyperangulated videolaryngoscopy in these situations.
MethodsOne or more optimization techniques were applied in 129 difficult Macintosh videolaryngoscopy cases in this secondary analysis of a prospective observational study. Stored videos were reviewed by at least three independent observers who assessed the POGO and six glottis view grades. A linear mixed regression and a linear regression model were fitted. Estimated marginal means were used to analyze differences between optimization maneuvers.
ResultsIn this study, 163 optimization maneuvers (77 direct epiglottis lifting, 57 hyperangulated videolaryngoscopy and 29 direct epiglottis lifting with a hyperangulated videolaryngoscope) were applied exclusively or sequentially. Vocal cords were not visible in 91.5% of the cases with Macintosh videolaryngoscopy, 24.7% with direct epiglottis lifting, 36.8% with hyperangulated videolaryngoscopy and 0% with direct lifting with a hyperangulated videolaryngoscope. Conversion to direct epiglottis lifting improved POGO (mean + 49.7%; 95% confidence interval [CI] 41.4 to 58.0; p < 0.001) and glottis view (mean + 2.2 grades; 95% CI 1.9 to 2.5; p < 0.001). Conversion to hyperangulated videolaryngoscopy improved POGO (mean + 43.7%; 95% CI 34.1 to 53.3; p < 0.001) and glottis view (mean + 1.9 grades; 95% CI 1.6 to 2.2; p < 0.001). The difference in POGO improvement between conversion to direct epiglottis lifting and conversion to hyperangulated videolaryngoscopy is: mean 6.0%; 95% CI −6.5–18.5%; hence non-inferiority was confirmed.
ConclusionWhen Macintosh videolaryngoscopy turned out to be difficult, glottis exposure with direct epiglottis lifting was non-inferior to the one gathered by conversion to hyperangulated videolaryngoscopy. A combination of both maneuvers yields the best result.
Clinical trial registrationClinicalTrials.gov, NCT03950934.

【研究背景与目的】目前尚不明确，当麦克金托什视频喉镜（Macintosh videolaryngoscopy）操作难度超出预期时，直接会厌提拉、换用高角度视频喉镜（hyperangulated videolaryngoscope），抑或联合高角度视频喉镜实施直接会厌提拉，是否可优化声门视野暴露。本研究旨在明确，在此类场景下，直接会厌提拉所带来的声门开口百分比（percentage of glottic opening, POGO）改善效果，是否不劣于换用高角度视频喉镜所达成的改善效果。【研究方法】本研究为一项前瞻性观察研究的二次分析，共纳入129例麦克金托什视频喉镜操作困难的病例，均应用了一种或多种声门视野优化技术。由至少3名独立观察者对存储的操作视频进行回顾分析，评估其声门开口百分比（POGO）及6级声门视野分级。本研究拟合了线性混合回归与线性回归模型，并采用估计边际均值分析不同优化操作间的差异。【研究结果】本研究中共实施163次声门视野优化操作（其中直接会厌提拉77次、换用高角度视频喉镜57次、联合高角度视频喉镜实施直接会厌提拉29次），操作可单独实施或序贯进行。麦克金托什视频喉镜操作时，91.5%的病例无法窥见声带；直接会厌提拉操作时该比例为24.7%，换用高角度视频喉镜时为36.8%，而联合高角度视频喉镜实施直接会厌提拉时为0%。换用直接会厌提拉可改善声门开口百分比（POGO，平均提升49.7%；95%置信区间[CI]：41.4~58.0；p<0.001）及声门视野分级（平均提升2.2级；95%CI：1.9~2.5；p<0.001）。换用高角度视频喉镜同样可改善POGO（平均提升43.7%；95%CI：34.1~53.3；p<0.001）及声门视野分级（平均提升1.9级；95%CI：1.6~2.2；p<0.001）。直接会厌提拉与换用高角度视频喉镜相比，POGO改善的差值均值为6.0%（95%CI：-6.5~18.5%），因此证实直接会厌提拉的效果不劣于高角度视频喉镜换用。【研究结论】当麦克金托什视频喉镜操作难度超出预期时，直接会厌提拉实现的声门暴露效果不劣于换用高角度视频喉镜的效果；联合使用两种操作方式可获得最优的声门暴露效果。【临床试验注册】ClinicalTrials.gov，NCT03950934。