So stick with me, because this sounds a little crazy at face value, but the more you think about it, the more it makes sense. I have still yet to hear why this would not work.
If you never watched Outbreak, you should go back and watch it. While sensational as it is, when you’re working with a deadly virus, an N95 is not the gold standard. It’s a hazmat suit. Unfortunately, all the healthcare workers in encapsulated hazmat suits is extremely costly and very unlikely to occur, but this is the next best thing.
Every hospital has filtered, breathable air piped through the entire hospital through the medical air lines. Now how and to what degree that air is filtered may vary, but should be certified through the Compressed Air and Gas Institute. This air is supplied in one of our hospitals by a series of large air compressors, similar to what you would buy at the hardware store, but much larger. The air intake is filtered by a carbon filter and a particulate filter. The system has to undergo quarterly and annual testing to ensure that air is safe and not sucking up some mold from the basement.
So how can we use this clean safe air for medical staff to breathe? The answer is a SAR or supplied air respirator. Everyone in healthcare by now has heard of a PAPR, which is a positive air pressure respirator. It works by blowing air across a HEPA filter through a hose and into a cap, helmet or hood. The beauty of this system is that it is positive pressure. Small aerosolized molecules cannot travel against a pressure gradient no more than they can travel upwind. So the system doesn’t have to have a complete 100% seal. You could duct tape a trash bag around your head and as long as there is positive pressure, it would work, not that I am suggesting that.
So a supplied air respirator works the same way, except that instead of a battery driven pump around your waste, you have an endless supply of generated medical air.
To do this you hook into the medical air line and use a devise such as the 3M V300 to convert and control the flow of air. This can also be done with 3M V100 which is awesome because it also cools the air. However, it cools the air at the expense of efficiency and uses a lot more air in the process.
Now is this practical for everyone in the hospital? Definitely not. But I do think alternatives like these could decrease our daily burn rate of N95s to a more manageable number. Wearing this is much more comfortable and tolerable for long periods than a N95 strapped to your face. I think the people in the hospital most suitable to use these would be a 1:1 ICU nurse and anesthesia. These are both groups of people at high risk of exposure who are stationary and adjacent to a medical air line. Feasibly, an ICU nurse could comfortably care for their ICU patient for hours on end inside the ICU room.
As the video below shows, this can also be done fairly cheaply with common hardware store compressed air components.
CAUTION: The risk in any PAPR or SAR is contamination in the doffing process. The air line could stay in the contaminated room, but the rest has to be cleaned and treated as contaminated every time it is taken off. Strict doffing procedures should be followed and monitored.