Aerosol-generating otolaryngology procedures and the need for enhanced PPE during the COVID-19 pandemic: a literature review

Abstract

Background: 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. Main body: 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.

Elective tracheostomy during COVID-19 outbreak: to whom, when, how? Early experience from Venice, Italy

“…Our preliminary experience and early experience from other Italian 26 38 and Chinese39 studies supports the safety of tracheostomy if appropriate protocols are strictly followed. After one month from the last tracheostomy we performed no one of our team developed symptoms of COVID-19.…”

Minimising aerosol spread during endoscopic sinus and skull base surgery. Experimental model evaluation of the efficacy of the microscope drape method

“…33 As per a recent paper by Guo et al, 34 the transmission distance of SARS-CoV-2 aerosol might reach 4 m. The same study also found that 'SARS-CoV-2 was widely distributed in the air and on object surfaces in both the intensive care unit and general ward, implying a potentially high infection risk for medical staff and other close contacts'. 33,34 Functional endoscopic sinus surgery, and anterior skull base surgery more specifically, typically entail manoeuvres and instrumentation employed in or through high viral load areas, which can cause aerosolisation of viral particles in the mucosa. 4,20 The use of drills, microdebriders, electrocautery, advanced energy devices and suctioning further promotes aerosol formation and the possible shedding of infectious microdroplets throughout the operating theatre.…”

“…This is especially important given the concerns regarding leaks in filtering facepiece code 2 masks and N95 mask respirators (used in many countries) during long procedures. 33 Adoption of the microscope drape technique could also result in faster operating theatre cleaning and turnover associated with the significantly reduced air particle or aerosol spread in the operating theatre by the end of the AGP, and potentially allow more liberal use of powered instruments during endonasal surgery. Furthermore, it could be argued that the use of an air particle counter in the operating theatre would be valuable for alerting staff to a potential significant aerosol leak through the drape, and assisting in decision making with respect to doffing PPE and operating theatre cleaning and turnover.…”

Head and neck oncological ablation and reconstruction in the COVID-19 era – our experience to date

“…A key focus at this point in the patient pathway is ensuring staff safety and the efficient use of resources. 14,15 This relates to the both the provision of theatre space in addition to the use of full personal protective equipment (PPE). Theatre list capacity has reduced due to the increased time required to intubate and extubate the patient.…”