Jubaer Hasan, Strickler Sarah, Farkas Dale, Dalton Caleb, Momin Mohammad A M, Dodson Kelley M, Hindle Michael, Longest Worth
Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA, United States of America.
Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA, United States of America.
AAPS PharmSciTech. 2025 Jan 16;26(1):34. doi: 10.1208/s12249-024-02987-4.
The administration of surfactant aerosol therapy to preterm infants receiving continuous positive airway pressure (CPAP) respiratory support is highly challenging due to small flow passages, relatively high ventilation flow rates, rapid breathing and small inhalation volumes. To overcome these challenges, the objective of this study was to implement a validated computational fluid dynamics (CFD) model and develop an overlay nasal prong interface design for use with CPAP respiratory support that enables high efficiency powder aerosol delivery to the lungs of preterm infants when needed (i.e., on-demand) and can remain in place without increasing the work of breathing compared with a baseline CPAP interface. Realistic in vitro experiments were first conducted to generate baseline validation data, and then the CFD model, once validated, was used to explore key design parameters across a range of preterm infant nose-throat geometries and aerosol delivery conditions. The most important factors for efficient aerosol delivery were shown to be (i) maintaining the aerosol delivery flow rate below the tracheal flow rate (to minimize CPAP line loss) and (ii) concentrating the aerosol within the first portion of the inhalation waveform. An optimized design was shown to deliver approximately 37-60% of the nominal dose through the system and to the lungs with low intersubject variability (1050-2200 g infants) across two modes of device actuation (automated and manual) with room for further improvement. Ergonomic curvatures and streamlining of the prong geometries were also found to reduce work of breathing and flow resistance compared with a commercial alternative.
对于接受持续气道正压通气（CPAP）呼吸支持的早产儿，进行表面活性剂气雾剂治疗极具挑战性，这是因为气道通路细小、通气流量相对较高、呼吸急促且吸入量小。为克服这些挑战，本研究的目标是实施一个经过验证的计算流体动力学（CFD）模型，并开发一种用于CPAP呼吸支持的叠加式鼻叉接口设计，该设计能够在需要时（即按需）将高效粉末气雾剂输送到早产儿肺部，并且与基线CPAP接口相比，能够在不增加呼吸功的情况下保持在位。首先进行了实际体外实验以生成基线验证数据，然后，经过验证的CFD模型被用于探索一系列早产儿鼻咽喉几何形状和气雾剂输送条件下的关键设计参数。高效气雾剂输送的最重要因素被证明是：（i）将气雾剂输送流速保持在气管流速以下（以尽量减少CPAP管路损失）；（ii）在吸气波形的第一部分内集中气雾剂。在两种设备驱动模式（自动和手动）下，一种优化设计显示可通过该系统并向肺部输送约37%-60%的标称剂量，且受试者间变异性较低（体重1050-2200克的婴儿），仍有进一步改进的空间。与市售替代品相比，还发现鼻叉几何形状的人体工程学曲率和流线型设计可降低呼吸功和流动阻力。
