Background Compared to continuous vibrating mesh nebulizer (VMN), inspiration synchronized VMN has shown increased inhaled dose during noninvasive ventilation; however, its use during aerosol delivery via high-flow nasal cannula (HFNC) is still unknown. Methods An adult manikin was connected to a dual-chamber model lung, which was driven by a critical care ventilator to simulate spontaneous breathing. A HFNC system was utilized with temperature at 37 ° C while gas flow at 5, 10, 20, 40, and 60 L/min. Inspiration synchronized and continuous aerosol generation were compared at different positions (at the inlet of humidifier vs close to patient). One milliliter of albuterol (2.5 mg/mL) was used in each run ( n = 3). Collection filter was placed at the trachea and was removed after each run. Drug was eluted from the filter and assayed with UV spectrophotometry (276 nm). Results When nebulizer was placed close to patient, inhaled dose was higher with inspiration synchronized than continuous aerosol generation at all gas flows ( p = 0.05) except at 5 L/min. When placed at the inlet of humidifier, compared to continuous, inspiration synchronized aerosol generated higher inhaled dose with gas flow set below 50% of patient inspiratory flow [23.9 (20.6, 28.3)% vs 18.1 (16.7, 19.6)%, p < 0.001], but lower inhaled dose with gas flow set above 50% of patient inspiratory flow [3.5 (2.2, 9.3)% vs 9.9 (8.2, 16.4)%, p = 0.001]. Regardless of breathing pattern, continuous aerosol delivered greater inhaled dose with nebulizer placed at humidifier than close to patient at all gas flows except at 5 L/min. Conclusion When the HFNC gas flow was set higher than 50% of patient inspiratory flow, no significant advantage was found in inspiration synchronized over continuous aerosol. However, inspiration synchronized aerosol generated 30% more inhaled dose than continuous with gas flow set below 50% of patient inspiratory flow, regardless of nebulizer placement. Continuous nebulizer needs to be placed at the inlet of humidifier.

中文翻译：

---

经鼻气雾输送过程中吸气同步雾化器与连续振动网状雾化器的体外比较


背景 与连续振动网状雾化器 (VMN) 相比，吸气同步 VMN 在无创通气期间显示出吸入剂量增加；然而，它在通过高流量鼻插管（HFNC）输送气雾剂期间的用途仍然未知。方法将成人模型连接至双腔模型肺，由重症监护呼吸机驱动模拟自主呼吸。使用 HFNC 系统，温度为 37°C，气流为 5、10、20、40 和 60 L/min。在不同位置（加湿器入口处与靠近患者）比较吸气同步和连续气雾产生。每次运行使用 1 毫升沙丁胺醇 (2.5 mg/mL) (n = 3)。收集过滤器放置在气管处并在每次运行后移除。将药物从过滤器中洗脱并用紫外分光光度法（276 nm）进行测定。结果 当雾化器靠近患者放置时，除 5 L/min 外，所有气流下（p = 0.05），与吸气同步的吸入剂量均高于连续气雾生成。当放置在加湿器入口时，与连续吸气同步气雾剂相比，气流设置低于患者吸气流量的 50%，可产生更高的吸入剂量 [23.9 (20.6, 28.3)% vs 18.1 (16.7, 19.6)%，p < 0.001 ]，但吸入剂量较低，气流设置高于患者吸气流量的 50% [3.5 (2.2, 9.3)% vs 9.9 (8.2, 16.4)%，p = 0.001]。无论呼吸模式如何，在除 5 L/min 以外的所有气流下，将雾化器放置在加湿器处时，连续气雾剂所输送的吸入剂量比靠近患者的雾化器要大。结论 当 HFNC 气流设置高于患者吸气流量的 50% 时，同步吸气与连续气雾相比没有发现显着优势。 然而，无论雾化器的放置位置如何，吸气同步气雾剂产生的吸入剂量比连续气雾剂多产生 30% 的吸入剂量，且气流设置低于患者吸气流量的 50%。连续雾化器需要放置在加湿器的入口处。