Mr Vieira and Drs Rodrigues, Sklar, and Brochard are affiliated with Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Unity Health Toronto, Ontario, Canada; and Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada. Dr Masy is affiliated with Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Unity Health Toronto, Ontario, Canada; Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada; and Division of Pediatric Critical Care, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada. Messrs LaRue and Laengert and Dr de Lannoy are affiliated with McMaster University, Center of Excellence in Protective Equipment and Materials, Hamilton, Ontario, Canada; and McMaster University, Department of Chemical Engineering, Hamilton, Ontario, Canada. Dr Lo is affiliated with Department of Anesthesiology and Pain Service, St. Michael's Hospital, Toronto, Ontario, Canada. Dr Petrosoniak is affiliated with Emergency Physician and Trauma Team, St. Michael's and Department of Medicine, University of Toronto, Ontario, Canada. Dr Rezende-Neto is affiliated with Trauma and Acute Care General Surgery, Department of Surgery, St. Michael's Hospital, Toronto, Ontario, Canada.
Respir Care. 2024 Mar 27;69(4):395-406. doi: 10.4187/respcare.11094.
Aerosol barrier enclosure systems have been designed to prevent airborne contamination, but their safety has been questioned. A vacuum tent was designed with active continuous suctioning to minimize risks of aerosol dispersion. We tested its efficacy, risk of rebreathing, and usability on a bench, in healthy volunteers, and in an ergonomic clinical assessment study.
First, a manikin with airway connected to a breathing simulator was placed inside the vacuum tent to generate active breathing, cough, and CO production; high-flow nasal cannula (HFNC) was applied in the manikin's nares. Negative pressure was applied in the vacuum tent's apex port using wall suction. Fluorescent microparticles were aerosolized in the vacuum tent for qualitative assessment. To quantify particles inside and around vacuum tent (aerosol retention), an airtight aerosol chamber with aerosolized latex microparticles was used. The vacuum tent was tested on healthy volunteers breathing with and without HFNC. Last, its usability was assessed in 5 subjects by 5 different anesthesiologists for delivery of full anesthesia, including intubation and extubation.
The vacuum tent was adjusted until no leak was visualized using fluorescent particles. The efficacy in retaining microparticles was confirmed quantitatively. CO accumulation inside the vacuum tent showed an inverse correlation with the suction flow in all conditions (normal breathing and HFNC 30 or 60 L/min) in bench and healthy volunteers. Particle removal efficacy and safe breathing conditions (CO, temperature) were reached when suctioning was at least 60 L/min or 20 L/min > HFNC flow. Five subjects were successfully intubated and anesthetized without ergonomic difficulties and with minimal interference with workflow and an excellent overall assessment by the anesthesiologists.
The vacuum tent effectively minimized aerosol dispersion. Its continuous suction system set at a high suction flow was crucial to avoid the spread of aerosol particles and CO rebreathing.
气溶胶屏障围护系统旨在防止空气传播污染，但它们的安全性受到质疑。我们设计了一种带有主动持续抽吸的真空帐篷，以最大限度地降低气溶胶扩散的风险。我们在台架上、健康志愿者中以及在符合人体工程学的临床评估研究中对其功效、再呼吸风险和可用性进行了测试。
首先，将连接有呼吸模拟器的气道的模拟人置于真空帐篷内，以产生主动呼吸、咳嗽和 CO 生成；高流量鼻导管（HFNC）置于模拟人的鼻腔内。使用墙壁抽吸在真空帐篷的顶点端口施加负压。在真空帐篷内雾化荧光微粒子进行定性评估。为了定量评估真空帐篷内和周围的颗粒（气溶胶保留），使用带有雾化乳胶微粒子的密封气溶胶室。在健康志愿者中，在有无 HFNC 的情况下测试真空帐篷。最后，由 5 位不同的麻醉师对其进行了 5 项可用性评估，以实现全身麻醉的交付，包括插管和拔管。
使用荧光粒子调整真空帐篷，直到看不到泄漏为止。通过定量证实了保留微粒子的功效。在所有条件（正常呼吸和 HFNC 30 或 60 L/min）下，CO 在真空帐篷内的积累与抽吸流量呈反比。当抽吸流量至少为 60 L/min 或 20 L/min > HFNC 流量时，达到了颗粒去除效率和安全呼吸条件（CO、温度）。5 名受试者成功插管和麻醉，没有出现人体工程学困难，并且麻醉医生对其整体评估极佳，几乎没有干扰工作流程。
真空帐篷有效地最大限度地减少了气溶胶的扩散。其连续抽吸系统设置在高抽吸流量至关重要，以避免气溶胶颗粒的传播和 CO 的再呼吸。
