Department of Otolaryngology - Head and Neck Surgery, University of Texas Health San Antonio, San Antonio, TX, USA.
Division of Critical Care Medicine, Department of Pediatrics, University of Washington, Seattle, WA, USA.
Int J Pediatr Otorhinolaryngol. 2021 Jun;145:110719. doi: 10.1016/j.ijporl.2021.110719. Epub 2021 Apr 18.
Heated and humidified high flow nasal cannula (HFNC) is an increasingly used form of noninvasive respiratory support with the potential to generate significant tracheal pressure. The aim of this study was to quantify the pressure generated by HFNC within the trachea in anatomically correct, pediatric airway models.
3D-printed upper airway models of a preterm neonate, term neonate, toddler, and small child were connected to a spontaneous breathing computerized lung model at age-appropriate ventilation settings. Two commercially available HFNC systems were applied to each airway model at increasing flows and the positive end-expiratory pressure (PEEP) was recorded at the level of the trachea.
Increasing HFNC flow produced a quadratically curved increase in tracheal pressure in closed-mouth models. The maximum flow tested in each model generated a tracheal pressure of 7 cm HO in the preterm neonate, 10 cm HO in the term neonate, 9 cm HO in the toddler, and 24 cm HO in the small child. Tracheal pressure decreased by at least 50% in open-mouth models.
HFNC was found to demonstrate a predictable flow-pressure relationship that achieved sufficient distending pressure to consider treatment of pediatric obstructive sleep apnea and tracheomalacia in the closed-mouth models tested.
加热和湿化高流量鼻导管（HFNC）是一种越来越多被使用的非侵入性呼吸支持方式，它有产生显著气管压力的潜力。本研究的目的是在解剖学上正确的儿科气道模型中量化 HFNC 在气管内产生的压力。
将早产儿、足月儿、幼儿和小孩的 3D 打印上气道模型与年龄相应的通气设置下的自主呼吸计算机化肺模型相连。将两种市售的 HFNC 系统分别应用于每个气道模型，在增加流量的同时记录气管内的呼气末正压（PEEP）。
HFNC 流量的增加导致闭口模型中气管压力呈二次曲线增加。每个模型中测试的最大流量在早产儿中产生 7cmH2O 的气管压力，在足月儿中产生 10cmH2O 的气管压力，在幼儿中产生 9cmH2O 的气管压力，在小孩中产生 24cmH2O 的气管压力。张口模型中气管压力至少降低了 50%。
HFNC 表现出可预测的流量-压力关系，在测试的闭口模型中产生了足够的扩张压力，可以考虑治疗小儿阻塞性睡眠呼吸暂停和气管软化。
