Vancouver – A few weeks after BC Public Health Officer Dr. Bonnie Henry pooh-poohed reports from scientists about airborne transmission of Sars-CoV-2, BC CDC has issued a bulletin precisely about the same possibility.
It now specifically warns about airborne transmission of the virus during certain medical procedures.
Dated Sept. 1, it warns medical professionals about Aerosol Generating Medical Procedures (AGMP.)
“AGMPs that generate small droplet nuclei in high concentration present a risk for airborne transmission of pathogens not otherwise able to spread by the airborne route (e.g. coronavirus, influenza virus),” BC CDC stated.
“Health care workers (HCWs) should conduct a Point-of- Care Risk Assessment prior to performing any AGMPs to determine the appropriate personal protective equipment (PPE) required, and to follow and implement additional measures outlined in their local health authority guidelines to minimize risk.”
BC CDC provided examples of “AGMPs requiring the use of an N95 Respirator for suspected or confirmed COVID-19 patients.”
“HCWs performing or assisting with the AGMP should wear the appropriate PPE: gown, gloves, eye protection and a fit-tested N95 respirator,” it said.
When over 200 scientists and air flow engineers asked the WHO to accept the possibility of airborne spread of the virus, Dr. Henry quickly dismissed the idea, calling it a “tempest in a teapot.”
She said she supported WHO. But WHO quickly changed its guidance warning health care workers to wear PPE during their entire shift and particularly during some procedures.
WHO also said it had worked with these scientists and engineers for several months.
But several studies now demonstrate that the virus is viable several metres away from someone shedding it through breathing or coughing.
BC CDC has produced a table of procedures that can propel the virus into the air.
“Local health authorities may have additional examples of AGMPs. For scenarios not described in the table, please contact your local Infection Prevention and Control team and/or the Medical Health Officer.”
Among procedures requiring N95 masks are :
- Airway suctioning (deep suction and open tracheal suctioning.)
- Intubation and extubation procedures.
- Breaking closed ventilation systems intentionally or un-intentionally.
- Bronchoscopy and bronchoalveolar lavage
- CPR with bag valve mask ventilation
- Continuous positive airway pressure (CPAP) or bilevel positive airway pressure (BiPAP)
- Direct laryngoscopy
- High flow oxygen therapy (including single and double flow O2 set ups, Optiflow and Airvo)
- Nasopharyngeal aspirates, washes and scoping* Nebulized therapy
- Tracheotomy Tracheostomy care
“Nasopharyngeal and throat swabs can be performed using contact and droplet precautions with gloves, gown, surgical/procedure mask and eye protection, and do not require the use of an N95 respirator.”
BC CDC bulletin