Rigo Vincent, Fayoux Pierre
Neonatology Division, CHU de Liège, CHR Citadelle, University of Liège, Liège, Belgium.
ORL et Chirurgie Cervico-Faciale Pédiatrique, Hôpital Jeanne de Flandre, CHRU Lille, Lille, France.
Paediatr Anaesth. 2018 Apr;28(4):361-366. doi: 10.1111/pan.13353. Epub 2018 Feb 26.
Adequate endotracheal tube positioning in preterm infants is complicated by the short length of the airway. Distal markers were designed to help with the insertion of endotracheal tubes at an appropriate depth below the vocal cords. However, those markers are not standardized between manufacturers, each tube size displays only one (sometimes 2) markers to provide information for infants of various gestational ages, and indicated distances are often too long for extremely preterm infants.
The study aims to describe vocal cords to mid-tracheal distance for different gestational ages and determine if depth markers should be adjusted accordingly.
Half the tracheal length added to the height of the posterior lamina of the cricoids approximates the distance between vocal cords and mid-trachea. Those dimensions were retrospectively retrieved from a database of laryngo-tracheal measurements obtained during autopsies of fetuses and newborn infants free of upper airway malformations. The equation of correlation between gestational age and distance from vocal cords to mid-trachea was used to calculate those distances for different gestational ages.
Data were derived from 114 patients. Vocal cords to mid-trachea distance is linearly correlated with gestational age (r = .90; distance = 2.831 + 0.6208 × gestational age). We suggest depth markers at 17.7, 19.0, 20.8, 22.7, 24.6, and 26.4 mm for gestational ages of 24, 26, 29, 32, 35, and 38 weeks, respectively, indicated by contrasting colors.
The linear relationship between laryngo-tracheal size and gestational age offers the opportunity to revise endotracheal tube depth markers for the smallest patients. Trials comparing those suggested markers with those currently in use are needed before implementation.
早产儿气道长度较短，这使得气管内导管的正确定位变得复杂。远端标记旨在帮助将气管内导管插入声带下方的适当深度。然而，这些标记在不同制造商之间并不统一，每个导管尺寸仅显示一个（有时两个）标记以为不同孕周的婴儿提供信息，并且对于极早产儿而言，指示的距离往往过长。
本研究旨在描述不同孕周的声带至气管中部的距离，并确定深度标记是否应相应调整。
环状软骨后板高度加上一半气管长度近似于声带与气管中部之间的距离。这些尺寸是从一组喉气管测量数据库中回顾性获取的，该数据库来自无气道上部畸形的胎儿和新生儿尸检。使用孕周与声带至气管中部距离之间的相关方程来计算不同孕周的这些距离。
数据来自114例患者。声带至气管中部的距离与孕周呈线性相关（r = 0.90；距离 = 2.831 + 0.6208×孕周）。我们建议，对于孕周分别为24、26、29、32、35和38周的婴儿，分别采用17.7、19.0、20.8、22.7、24.6和26.4毫米的深度标记，并用对比色表示。
喉气管大小与孕周之间的线性关系为修订最小患者的气管内导管深度标记提供了机会。在实施之前，需要进行试验比较这些建议的标记与当前使用的标记。
