Shrimpton A J, O'Farrell G, Howes H M, Craven R, Duffen A R, Cook T M, Reid J P, Brown J M, Pickering A E
Anaesthesia, Pain and Critical Care Sciences, School of Physiology, Pharmacology and Neuroscience, University of Bristol, UK.
Department of Anaesthesia, University Hospitals Bristol and Weston Foundation Trust, Bristol, UK.
Anaesthesia. 2023 May;78(5):587-597. doi: 10.1111/anae.15968. Epub 2023 Jan 29.
Aerosol-generating procedures are medical interventions considered high risk for transmission of airborne pathogens. Tracheal intubation of anaesthetised patients is not high risk for aerosol generation; however, patients often perform respiratory manoeuvres during awake tracheal intubation which may generate aerosol. To assess the risk, we undertook aerosol monitoring during a series of awake tracheal intubations and nasendoscopies in healthy participants. Sampling was undertaken within an ultraclean operating theatre. Procedures were performed and received by 12 anaesthetic trainees. The upper airway was topically anaesthetised with lidocaine and participants were not sedated. An optical particle sizer continuously sampled aerosol. Passage of the bronchoscope through the vocal cords generated similar peak median (IQR [range]) aerosol concentrations to coughing, 1020 (645-1245 [120-48,948]) vs. 1460 (390-2506 [40-12,280]) particles.l respectively, p = 0.266. Coughs evoked when lidocaine was sprayed on the vocal cords generated 91,700 (41,907-166,774 [390-557,817]) particles.l which was significantly greater than volitional coughs (p < 0.001). For 38 nasendoscopies in 12 participants, the aerosol concentrations were relatively low, 180 (120-525 [0-9552]) particles.l , however, five nasendoscopies generated peak aerosol concentrations greater than a volitional cough. Awake tracheal intubation and nasendoscopy can generate high concentrations of respiratory aerosol. Specific risks are associated with lidocaine spray of the larynx, instrumentation of the vocal cords, procedural coughing and deep breaths. Given the proximity of practitioners to patient-generated aerosol, airborne infection control precautions are appropriate when undertaking awake upper airway endoscopy (including awake tracheal intubation, nasendoscopy and bronchoscopy) if respirable pathogens cannot be confidently excluded.
气溶胶生成操作是被认为具有通过空气传播病原体高风险的医疗干预措施。对麻醉患者进行气管插管产生气溶胶的风险不高；然而，患者在清醒气管插管期间经常进行呼吸动作，这可能会产生气溶胶。为了评估风险，我们在一系列健康参与者的清醒气管插管和鼻内镜检查过程中进行了气溶胶监测。采样在超净手术室中进行。操作由12名麻醉实习生执行并接受。上呼吸道用利多卡因进行局部麻醉，参与者未使用镇静剂。光学粒子计数器持续对气溶胶进行采样。支气管镜通过声带产生的气溶胶浓度峰值中位数（四分位间距[范围]）与咳嗽相似，分别为1020（645 - 1245[120 - 48,948]）个/升和1460（390 - 2506[40 - 12,280]）个/升，p = 0.266。在声带喷洒利多卡因时诱发的咳嗽产生91,700（41,907 - 166,774[390 - 557,817]）个/升，显著高于自主咳嗽（p < 0.001）。对于12名参与者的38次鼻内镜检查，气溶胶浓度相对较低，为180（120 - 525[0 - 9552]）个/升，然而，有5次鼻内镜检查产生的气溶胶浓度峰值高于自主咳嗽。清醒气管插管和鼻内镜检查可产生高浓度的呼吸道气溶胶。特定风险与喉部利多卡因喷雾、声带操作、操作过程中的咳嗽和深呼吸有关。鉴于从业者与患者产生的气溶胶距离较近，如果不能确定排除可吸入病原体，则在进行清醒上呼吸道内镜检查（包括清醒气管插管、鼻内镜检查和支气管镜检查）时采取空气传播感染控制预防措施是合适的。
