Covid-19 doctors ready to take the plunge in snorkel masks when next wave hits

18 September 2021 - 10:09
Anaesthesia registrars Ashraf Petersen, left, and Tiaan de Villiers from the University of Cape Town wear full-face snorkel masks during research into their suitability as an alternative for N95 masks.
Anaesthesia registrars Ashraf Petersen, left, and Tiaan de Villiers from the University of Cape Town wear full-face snorkel masks during research into their suitability as an alternative for N95 masks.
Image: Suppiled by Ronel Herselman

When the next Covid-19 wave crashes down on health workers, snorkelling equipment could save them.

This follows simulations at the universities of Pretoria and Cape Town which found wide approval of full-face snorkel masks among the 52 doctors who tried them.

Researchers said the masks could be a viable alternative during aerosol-generating procedures when standard personal protective equipment (PPE) is not available.

“Although, the full-face snorkel mask is an expensive alternative to the N95 and visor. We do not advocate replacement of traditional PPE, but that the full-face snorkel mask can be a viable alternative when N95s are not available,” they reported in the African Journal of Emergency Medicine.

Most of the medical officers, registrars and consultants who donned the mask before simulating an intubation on a manikin reported no fogging, humidity or irritation.

“It was reportedly easy to speak while wearing the mask, although some participants perceived that they were not always understood,” the researchers said.

“Twenty-one participants experienced a subjective physiological effect from wearing the mask; most commonly a sensation of shortness of breath.”

Several international studies have shown full-face snorkel masks are an efficient and safe alternative to N95 respirators, goggles and face shields, “but they are not commonly available or used in high-risk settings such as emergency centres and critical care units in Africa”, said researchers led by Ronel Herselman, the head of undergraduate and surgical skills laboratories in UP's health sciences faculty.

“It is important to examine the development of standardised procedures for donning, doffing and decontamination of these masks in the African context,” they said.

“Local studies on these masks can contribute to creating awareness of safe and suitable alternatives amidst global shortages of traditional personal protective equipment.”

Doctors Masekane Walter Shilenge and Kgomotso Mabelane from Steve Biko Academic Hospital in Pretoria test full-face snorkel masks during an intubation on a mannikin.
Doctors Masekane Walter Shilenge and Kgomotso Mabelane from Steve Biko Academic Hospital in Pretoria test full-face snorkel masks during an intubation on a mannikin.
Image: Supplied by Ronel Herselman

N95 masks plus a visor or goggles cost around R142, while the snorkel masks used in the study cost R1,535 plus R30 a day for a new filter.

The microbial filter used in the test was 99.99% effective at capturing aerosols, which are lightweight particles from a patient's respiratory tract that can remain suspended in the air.

The researchers said the benefits of snorkel masks include limitation of direct hand contact with the face, protection against large droplets, and reusability in times of equipment shortage. “Reusable masks are also cheaper than single-use respirators when in frequent use.”

Prof Ronel Herselman
Prof Ronel Herselman
Image: University of Pretoria

They mentioned a Stellenbosch University study in 2020 which found that health workers performing bronchoscopies on children with Covid-19 while wearing snorkel masks reported no infections at a time when the overall Covid-19 prevalence rate among staff was 13.5%.

In the new study, the masks' fit was tested by asking doctors to breathe normally, breathe deeply, turn their head from side to side, nod their head, read out loud and jog on the spot.

Herselman said the masks were worn for an average of 27 minutes by each doctor, and more tests would be needed if they were to be worn for intensive care shifts or surgery in the operating theatre.

However, because of the high aerosol risk when intubating patients, “novel devices that can provide a safe alternative during the Covid-19 pandemic must be investigated”, the paper said.

“Our research suggests that the adapted full-face snorkel masks were considered safe, easy to use and comfortable to wear, with limited chances of cross-contamination during donning, doffing, and when performing procedures.

“Finally, with the dramatic increases in scarcity and prices of N95 masks and face shields, these reusable masks are an affordable alternative.”

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