With new variants emerging, some experts have projected COVID-19 will become an endemic, seasonal disease. And while supply chain issues like those experienced at the beginning of the pandemic are unlikely—though not out of the question—personal protective equipment will continue to be pivotal, especially for those on the frontlines.
At the start of the pandemic, when nurses were suffering from bruised faces and people couldn’t get a hold of disposable face masks, respiratory physicians at University Hospital Southampton, the engineering department at the University of Southampton, and a local electronics company formed a collaboration to develop a safe, sustainable PPE alternative.
Powered air-purifying respirators (PeRSo) is what the team came up with, and now, they have successfully implemented them on a large-scale with the approval of the UK Health and Safety Executive.
Just 4 weeks after seeing the urgent need for better PPE, the team began mass producing PeRSo for potential use within National Health Service hospitals in Australia. The respirators comprise a battery-operated fan held on a belt, which draws air in through a HEPA filter and delivers clean air via a corrugated tube into an overhead hood with a clear, plastic visor. Battery life is up to 8 hours, and they are quick and easy to change during a nurse or doctor’s shift.
The researchers say the implementation process was complex. While waiting for approval from HSE for use as a replacement for N95 face masks and eye protection, a pilot deployment was launched. In the first wave—from April 21 to Aug. 6, 2020—1,896 respirators were given to staff on “red” COVID-19 wards in addition to emergency department staff caring for patients of unknown infection status.
During the pilot deployment, the research team electronically sent two surveys to participants, one regarding standard issue PPE and the other regarding their use of PeRSo thus far.
More than half of the survey respondents reported PeRSo was “quite comfortable” compared with standard droplet or airborne precautions. Respondents also said PeRSo was easier to put on, and the patients favored it as they could see their nurse’s/doctor’s faces in full, making communication easier.
Noise was predictably an issue, with some respondents saying the fan inside the hood caused hearing impairment. To accommodate, the team modified the hood for the upcoming second wave with a sleeker, off-ear design.
With both staff and patients giving a thumbs up to PeRSo, the researchers then conducted an economic analysis of mass PeRSo use. The team simulated multiple scenarios, 60% of which showed the cost-effectiveness of PeRSo. The central finding was that PeRSo net cost savings increase with the number of patients on intensive care and with the length of time from deployment.
“PeRSo use becomes cost saving more rapidly in the scenario where PPE consists of 100% FFP3 respirators, achieving cost neutrality at 90 days when 20 beds are occupied, and becoming progressively more cost savings thereafter,” write the researchers in t heir study, published in Frontiers in Medical Technology. “When PPE consists of a mixture of FFP3 respirators and surgical facemasks, cost neutrality for PeRSo use is reached at 155 days, when 20 beds are occupied.”
The second, ongoing UK wave of the pandemic that started in November 2020 gave researchers the chance to evaluate real-world impact of PeRSo mass deployment.
Rather than give the respirators to specific wards, this time staff were asked to request one by e-mailing a central distribution hub. Over 3,600 staff requested a respirator, out of a total of 6,431 clinically active staff across the hospital network.
To determine whether respirator increased or reduced staff infection, the researchers compared absences due to COVID-19 in the NHS hospitals to similar hospitals in England. Not only did they find low overall infection rates in the Australian hospital, but they also saw a drop in overall absences.
There was a sharp peak in absences in most NHS hospitals after the New Year, but this rapidly fell over the same 4-week period that PeRSo use increased. Specifically, the researchers recorded a 3.4-fold drop in absences over 4 weeks after the peak compared with an average 1.9-fold fall in the comparator hospitals.
“This is a prime example of the local hospital, university and industry working together to come up with an innovative solution to the crisis that has benefited patients and staff alike,” said Trevor Smith, Deputy Chief Medical Officer at University Hospital Southampton. “Our experience can help the wider NHS to improve its PPE provision as we enter a difficult winter.”
Photo: PeRSo being assembled by manufacturer INDO Lighting. Credit: INDO Lighting