University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
Department of Otolaryngology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
Ann Otol Rhinol Laryngol. 2021 Nov;130(11):1245-1253. doi: 10.1177/00034894211000502. Epub 2021 Mar 18.
Define aerosol and droplet risks associated with routine otolaryngology clinic procedures during the COVID-19 era.
Clinical procedures were simulated in cadaveric heads whose oral and nasal cavities were coated with fluorescent tracer (vitamin B2) and breathing was manually simulated through retrograde intubation. A cascade impactor placed adjacent to the nares collected generated particles with aerodynamic diameters ≤14.1 µm. The 3D printed models and syringes were used to simulate middle and external ear suctioning as well as open suctioning, respectively. Provider's personal protective equipment (PPE) and procedural field contamination were also recorded for all trials using vitamin B2 fluorescent tracer.
The positive controls of nebulized vitamin B2 produced aerosol particles ≤3.30 µm and endonasal drilling of a 3D model generated particles ≤14.1 µm. As compared with positive controls, aerosols and small droplets with aerodynamic diameter ≤14.1 µm were not detected during rigid nasal endoscopy, flexible fiberoptic laryngoscopy, and rigid nasal suction of cadavers with simulated breathing. There was minimal to no field contamination in all 3 scenarios. Middle and external ear suctioning and open container suctioning did not result in any detectable droplet contamination. The clinic suction unit contained all fluorescent material without surrounding environmental contamination.
While patients' coughing and sneezing may create a baseline risk for providers, this study demonstrates that nasal endoscopy, flexible laryngoscopy, and suctioning inherently do not pose an additional risk in terms of aerosol and small droplet generation. An overarching generalization cannot be made about endoscopy or suctioning being an aerosol generating procedure.
定义 COVID-19 时代耳鼻喉科常规临床操作相关的气溶胶和飞沫风险。
在尸体头部涂抹荧光示踪剂（维生素 B2）模拟临床操作，模拟口腔和鼻腔；通过逆行插管模拟呼吸。将级联冲击器放置在鼻腔旁边，收集空气动力学直径≤14.1μm 的生成颗粒。使用 3D 打印模型和注射器分别模拟中耳和外耳抽吸以及开放式抽吸。所有试验均使用维生素 B2 荧光示踪剂记录术者个人防护装备（PPE）和操作区域污染情况。
雾化维生素 B2 的阳性对照产生了≤3.30μm 的气溶胶颗粒，3D 模型的经鼻内钻孔产生了≤14.1μm 的颗粒。与阳性对照相比，刚性鼻内镜检查、软性纤维喉镜检查和模拟呼吸的尸体刚性鼻腔抽吸过程中未检测到≤14.1μm 空气动力学直径的气溶胶和小液滴。在所有 3 种情况下，污染区域都很少或没有污染。中耳和外耳抽吸以及开放式容器抽吸均未导致可检测的飞沫污染。临床抽吸装置内含有所有荧光材料，周围环境没有污染。
虽然患者咳嗽和打喷嚏可能会对医护人员造成基线风险，但本研究表明，鼻内镜检查、软性喉镜检查和抽吸操作本身不会增加气溶胶和小液滴生成的风险。不能一概而论地认为内镜检查或抽吸操作是气溶胶生成程序。
3 级
