Wang Yang, Li Jiayu, Leavey Anna, O'Neil Caroline, Babcock Hilary M, Biswas Pratim
1 Aerosol and Air Quality Research Laboratory, Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis , St. Louis, Missouri.
2 Infectious Diseases Division, School of Medicine, Washington University in St. Louis , St. Louis, Missouri.
J Aerosol Med Pulm Drug Deliv. 2017 Apr;30(2):132-140. doi: 10.1089/jamp.2016.1340. Epub 2016 Dec 15.
Medical nebulizers are widely and conveniently used to deliver medication to the lungs as an inhalable mist; however, the deposition of nebulized particles in the human respiratory system and the transport of the nebulized particles in the environment have not been studied in detail.
Five medical nebulizers of three different types (constant output, breath enhanced, and dosimetric) were evaluated. The size distribution functions (SDFs) and respiratory deposition of the particles generated from the nebulizers were characterized. The SDFs were obtained with an aerodynamic particle sizer (APS; TSI, Inc., St. Paul) after data correction, and the respiratory deposition was calculated according to the model developed by the International Commission on Radiological Protection. The evaporation, Brownian diffusion, and convective movement are further calculated based on aerosol properties.
The SDFs measured by the APS indicated that most of the generated particles were in the size range of 1-8 μm. The operating pressure and flow rate affected the number-based SDF of the nebulized particles. Although different values of mean aerodynamic diameter (MAD) were obtained for the nebulizers, the mass median aerodynamic diameter did not differ significantly from each other (between 4 and 5 μm). According to calculation, the deposition of particles in the head airways region accounted for the most of the particle mass collected by the respiratory system. Convective movement was the dominant mechanism for the transport of particles in the size ranges investigated. Relative humidity-dependent evaporation can significantly decrease the size of the emitted particles, resulting in a different respiratory deposition pattern such that the amount of particles deposited in the alveolar region is greatly enhanced. Appropriate protection from these particles should be considered for those persons for whom the medication is not intended (e.g., healthcare workers, family members).
医用雾化器被广泛且方便地用于将药物以可吸入雾气的形式输送到肺部；然而，雾化颗粒在人体呼吸系统中的沉积以及雾化颗粒在环境中的传输尚未得到详细研究。
对三种不同类型（恒量输出型、呼吸增强型和剂量型）的五台医用雾化器进行了评估。对雾化器产生的颗粒的粒径分布函数（SDFs）和呼吸道沉积进行了表征。在数据校正后，使用空气动力学粒径分析仪（APS；TSI公司，圣保罗）获得SDFs，并根据国际放射防护委员会开发的模型计算呼吸道沉积。基于气溶胶特性进一步计算蒸发、布朗扩散和对流运动。
APS测量的SDFs表明，产生的大多数颗粒尺寸在1-8μm范围内。工作压力和流速影响雾化颗粒的基于数量的SDF。尽管雾化器获得的平均空气动力学直径（MAD）值不同，但质量中位空气动力学直径彼此之间没有显著差异（在4至5μm之间）。根据计算，颗粒在头部气道区域的沉积占呼吸系统收集的颗粒质量的大部分。对流运动是所研究尺寸范围内颗粒传输的主要机制。与相对湿度相关的蒸发可显著减小排放颗粒的尺寸，导致不同的呼吸道沉积模式，从而大大增加沉积在肺泡区域的颗粒数量。对于非目标用药人群（如医护人员、家庭成员），应考虑对这些颗粒进行适当防护。
