Simulations to test the effectiveness of personal protective equipment (PPE) may reveal shortcomings in both the equipment and in the manner that PPEs are used, a new study suggests.

Canadian researchers testing PPEs in an airway-management simulation scenario found the equipment they were using might not adequately protect medical personnel caring for a real patient with COVID-19, according to the report in the Canadian Journal of Anesthesiology.

With the help of a mannequin that could “cough” up a mixture containing Glo Germ powder, the study team ran a series of simulations involving different types of protective attire. The Glo Germ powder is a product designed to mimic the spread of microorganisms.

The powder was brushed onto the surface of the simulation mannequin and also loaded into the mannequin’s nostrils. While health care workers were working on the mannequin, it coughed up droplets containing the powder. When the workers wore reusable yellow gowns that were permeable to liquid, six out of six had visible soilage on their scrubs beneath their gowns.

During one simulation, an airway assistant wearing a disposable Advancement of Medical Instrumentation level-3 surgical gown showed no contamination of the scrubs beneath the gown, but there was significant contamination on that health care worker’s neck, on the base of the wrist, and on the lower pants and shoes.

“While skin contamination is not a method of transmission for the severe acute respiratory syndrome coronavirus-2 responsible for causing COVID-19, these areas of soilage increase the risk for self-contamination (e.g., during doffing) via mucous membranes,” write the authors, led by Dr. Shannon Lockhart, of the department of anesthesiology at St. Paul’s Hospital and the University of British Columbia in Vancouver.

The study authors did not respond to requests for comment.

Contamination could also occur while health care workers disrobed, Dr. Lockhart and her team found. The researchers suggested that the doffing process be adjusted to the types of PPEs used, and it must be practiced, they said.

In their simulations, Glo Germ was found on faces, necks, forearms and shoes after participants disrobed.

The new study underscores the importance of practicing with simulations, said Dr. Jennifer Arnold, a neonatologist and medical director of simulation at Johns Hopkins All Children’s Hospital in Baltimore.

“One critical message is that identification of the proper PPE coverage is key to protection and testing this with simulation is a safe and effective way to optimize safety for our clinicians,” Dr. Arnold said in an email. “Additionally, this article demonstrates the challenge of performing effective donning and doffing procedures”