Department of Pediatric Anesthesia, Montreal Children’s Hospital, Montreal, Quebec, Canada.
Anesth Analg. 2013 Aug;117(2):462-70. doi: 10.1213/ANE.0b013e3182991d42. Epub 2013 Jun 11.
To date, the lengths of the subglottic and tracheal airway segments have been measured from autopsy specimens. Images of the head and neck obtained from computerized tomography (CT) provide an alternate method. Our objective in this study was to identify anatomic landmarks from CT scans in infants and young children to estimate the lengths of the subglottic and tracheal airway segments and to correlate these lengths with age.
We performed a retrospective analysis of CT images of the neck for various diagnostic indications in children ≤3 years. We obtained planes of reconstruction at the level of the vocal cords (VCs), cricoid cartilage, and carina (C) which were parallel to each other and perpendicular to sagittal long axis of the trachea. The lengths of the subglottic airway (LengthSG) and total length of the laryngotracheal airway (LengthVC-C) were measured from the distance between, respectively, the VC versus cricoid cartilage and the VC versus C planes of reconstruction. Tracheal length was then calculated as the difference between LengthVC-C and LengthSG.
Fifty-six children met the inclusion criteria. There were 29 boys. The median weight was 10.7 kg (range 3.1-19.0 kg). Regression analysis yielded mean LengthSG (mm) = 7.8 + 0.03·corrected age (months), r(2) = 0.07, P = 0.056; lower and upper 95% confidence interval for β = 0.03 were -0.001 and 0061. The mean LengthSG was 8.4 mm with an SD of 1.4 mm. The 95th percentile for LengthSG was 10.8 mm, and the 5% to 95% interquartile range was 4.9 mm. The estimate for the 95% confidence interval of the 95th percentile was between 10.2 and 11.3 mm. The LengthVC-C increased with age: mean LengthVC-C (cm) = 5.3 + 0.05·corrected age (months), r(2) = 0.7, P < 0.001. Tracheal length also increased with age: mean tracheal length (cm) = 4.5 + 0.05·corrected age (months), r(2) = 0.6, P < 0.001.
We report a novel estimate method for the lengths of the airway segments between the VC and C in 56 infants and young children and suggest that the growth characteristics of the subglottic and tracheal airway may differ.
迄今为止，声门下和气管气道段的长度是从尸检标本中测量得到的。计算机断层扫描（CT）获得的头颈部图像提供了一种替代方法。我们的目标是从 CT 扫描中识别出婴儿和幼儿的解剖学标志，以估计声门下和气管气道段的长度，并将这些长度与年龄相关联。
我们对≤3 岁儿童的各种诊断适应症进行了颈部 CT 图像的回顾性分析。我们获得了与气管矢状长轴平行且垂直于声带（VC）、环状软骨和隆突（C）平面的重建平面。声门下气道长度（LengthSG）和喉气管气道总长度（LengthVC-C）分别从 VC 与环状软骨和 VC 与 C 重建平面之间的距离测量。然后，气管长度计算为 LengthVC-C 与 LengthSG 之间的差值。
56 名儿童符合纳入标准。其中 29 名男孩。中位数体重为 10.7kg（范围 3.1-19.0kg）。回归分析得出 MeanLengthSG（mm）=7.8+0.03·校正月龄，r²=0.07，P=0.056；β=0.03 的下和上 95%置信区间为-0.001 至 0061。MeanLengthSG 为 8.4mm，标准差为 1.4mm。LengthSG 的第 95 个百分位数为 10.8mm，5%至 95%的四分位间距为 4.9mm。LengthSG 第 95 个百分位数的 95%置信区间估计值在 10.2 至 11.3mm 之间。LengthVC-C 随年龄增长而增加：MeanLengthVC-C（cm）=5.3+0.05·校正月龄，r²=0.7，P<0.001。气管长度也随年龄增长而增加：MeanTrachealLength（cm）=4.5+0.05·校正月龄，r²=0.6，P<0.001。
我们报告了一种新的估计方法，用于测量 56 名婴儿和幼儿 VC 与 C 之间气道段的长度，并表明声门下和气管气道的生长特征可能不同。
