Even at the Clinic, COVID-19 Could Be in the Air

Airborne aerosols were generated during speech, sneezing, and during nasal endoscopy procedures in an otolaryngology clinic, reinforcing the importance of universal source control during the COVID-19 epidemic, researchers found.

In a simulated clinical setting, speech and nasal endoscopy generated significant airborne aerosols, though simulated sneezing generated the largest number of airborne aerosols, reported Benjamin Bleier, MD, of Massachusetts Eye and Ear Infirmary in Boston, and colleagues.

While a surgical mask helped to partially mitigate airborne aerosol generation, an N95 respirator helped to contain airborne particle generation, the authors wrote in Otolaryngology — Head and Neck Surgery.

Bleier told MedPage Today that evidence that SARS-CoV-2, the virus that causes COVID-19, has high viral load in the nasopharynx is concerning for healthcare providers in general, but especially for otolaryngologists. A nasal endoscopy involves inserting a scope inside a patient’s nose, which initiates “direct contact between the instrument and the airway tissue, causing the patient to perform involuntary behavior,” such as coughing or sneezing, he explained.

And most literature supports the idea that talking generates more aerosols than coughing, as Bleier noted that prior research supports the idea that “talking alone is worrisome for aerosol generation, even in a closed environment with someone infected.”

“In an environment where testing is not widely available or reliable, we have to adopt the posture of universal source control,” he said. “We have to assume all patients are positive [for COVID-19] and treat them as such.”

For doctors, even in the clinic setting, this means full personal protective equipment (PPE): gown, gloves, mask, and goggles or eye protection. Because of airborne aerosols the patient generates in the room, this also means engineering control, Bleier added, such as the heating, ventilation, and air conditioning system turning over the air supply in the room.

“Close the room for an hour, let the air circulate, clean all surfaces, and then the next patient can come in,” he said.

Bleier and his team even proposed a solution for otolaryngologists who have to do nasal endoscopies: a version of the N95 mask, with a small piece of latex glove stapled to the inside and outside. The scope is passed through that section of the mask, with the latex providing a seal adequate to prevent pathogen transmission.

Bleier said that in addition to having both patients and providers be masked, it is also important to ensure that patients don’t pull down their masks.

“Even though it wasn’t statistically significant, it has the potential to release airborne particles into the room. Data alone suggests the mask needs to remain on the patient’s mouth,” he said.

Bleier’s group also focused on surgical procedures specific to otolaryngologists by using different surgical instruments in a cadaver head. The team found that transnasal drill and cautery use were both associated with significant airborne particulate matter production under surgical conditions.

Bleier said his group’s study helped “peel back the veil” on the aerosols to which healthcare providers are exposed, which has gained a heightened importance in this era of COVID-19.

“We always have been, but we just weren’t paying attention to it,” he said. “This will have a long-term effect on the precautions we take.”

Last Updated May 27, 2020