Department of Surgery, University of Saskatchewan, 2708-103 Hospital Drive, Saskatoon, SK, S7N 0W8, Canada.
Department of Surgery, University of Saskatchewan, Wall Street ENT Clinic, 230-140 Wall Street, Saskatoon, SK, S7K 1N4, Canada.
J Otolaryngol Head Neck Surg. 2020 May 11;49(1):29. doi: 10.1186/s40463-020-00424-7.
Adequate personal protective equipment is needed to reduce the rate of transmission of COVID-19 to health care workers. Otolaryngology groups are recommending a higher level of personal protective equipment for aerosol-generating procedures than public health agencies. The objective of the review was to provide evidence that a.) demonstrates which otolaryngology procedures are aerosol-generating, and that b.) clarifies whether the higher level of PPE advocated by otolaryngology groups is justified.
Health care workers in China who performed tracheotomy during the SARS-CoV-1 epidemic had 4.15 times greater odds of contracting the virus than controls who did not perform tracheotomy (95% CI 2.75-7.54). No other studies provide direct epidemiological evidence of increased aerosolized transmission of viruses during otolaryngology procedures. Experimental evidence has shown that electrocautery, advanced energy devices, open suctioning, and drilling can create aerosolized biological particles. The viral load of COVID-19 is highest in the upper aerodigestive tract, increasing the likelihood that aerosols generated during procedures of the upper aerodigestive tract of infected patients would carry viral material. Cough and normal breathing create aerosols which may increase the risk of transmission during outpatient procedures. A significant proportion of individuals infected with COVID-19 may not have symptoms, raising the likelihood of transmission of the disease to inadequately protected health care workers from patients who do not have probable or confirmed infection. Powered air purifying respirators, if used properly, provide a greater level of filtration than N95 masks and thus may reduce the risk of transmission.
Direct and indirect evidence suggests that a large number of otolaryngology-head and neck surgery procedures are aerosol generating. Otolaryngologists are likely at high risk of contracting COVID-19 during aerosol generating procedures because they are likely exposed to high viral loads in patients infected with the virus. Based on the precautionary principle, even though the evidence is not definitive, adopting enhanced personal protective equipment protocols is reasonable based on the evidence. Further research is needed to clarify the risk associated with performing various procedures during the COVID-19 pandemic, and the degree to which various personal protective equipment reduces the risk.
为了降低 COVID-19 向医护人员传播的速度，需要配备足够的个人防护设备。耳鼻喉科团体建议对产生气溶胶的操作采用比公共卫生机构更高水平的个人防护设备。本综述的目的是提供证据，证明：a）哪些耳鼻喉科手术会产生气溶胶，以及 b）阐明耳鼻喉科团体提倡的更高水平的个人防护设备是否合理。
在中国 SARS-CoV-1 流行期间进行气管切开术的医护人员感染病毒的几率比未进行气管切开术的对照组高 4.15 倍（95%CI 2.75-7.54）。没有其他研究提供耳鼻喉科手术过程中病毒气溶胶传播增加的直接流行病学证据。实验证据表明，电烙术、高级能量设备、开放式抽吸和钻孔都可以产生气溶胶化的生物颗粒。COVID-19 的病毒载量在上呼吸道最高，增加了感染患者上呼吸道操作过程中产生的气溶胶携带病毒物质的可能性。咳嗽和正常呼吸会产生气溶胶，这可能会增加门诊操作过程中传播的风险。很大一部分感染 COVID-19 的人可能没有症状，这增加了未感染的患者向防护不当的医护人员传播疾病的可能性。如果正确使用，动力空气净化呼吸器提供的过滤水平高于 N95 口罩，因此可以降低传播的风险。
直接和间接证据表明，大量耳鼻喉科-头颈外科手术会产生气溶胶。耳鼻喉科医生在进行产生气溶胶的操作时，很可能感染 COVID-19，因为他们可能接触到感染病毒的患者的高病毒载量。基于预防原则，即使证据不明确，根据证据，采用增强的个人防护设备方案是合理的。需要进一步研究来阐明在 COVID-19 大流行期间进行各种手术的风险，以及各种个人防护设备降低风险的程度。
