Edit: this development looks very promising for 'sub-intensive' cases -- adapting decathlon masks to provide positive air pressure (to help reinflate lungs) without intubation or leaking contaminated exhaust: https://www.isinnova.it/easy-covid19-eng/. Some emerging theories of pathology suggest that lung function can be increased by reinflating collapsed alveoli with constant pressure: https://emcrit.org/pulmcrit/cpap-covid/
Non Hail-Mary Ventilators have only a 30% survival rate at 1 year mark:
https://www.ncbi.nlm.nih.gov/pubmed/8404197
Incidentally, that's exactly why medical systems to not stockpile ventilators. Under reasonable condition, the number of ventilators closely mirrors the expected number of Hail Mary procedures done at a given time and some spare units.
https://www.thelancet.com/journals/lancet/article/PIIS0140-6...
Plus you need nurses and doctors to intubate the patient and setup and monitor the actual ventilator. The machine itself is a small part of the equation.
I think the focus on ventilators is somewhat misleading. If you need mechanical ventilation, you're a goner anyway, and your bed and healthcare staff could be better used on someone else. The 'lack' of a machine is just a very visible component.
The complications of ventilators and whatever lasting damage is caused by the disease itself; will be killing a significant portion of the recovered population, will it not?
If they do, then less hospitalization, and less ICU / ventilator needs.
If Chloroquine doesn't end up working, basically we need to find something that does, because that is the only feasible way to get us out of this mess. We have shuttered the economy because the healthcare system can't handle so many people needing hospitalization. The only scalable way around that is to find a treatment that significantly lowers the need for hospitalization.
No, building a ventilator is like building an engine because you need to go to the store - you're missing so much of the solution to the problem. I've also posted before [1] on why they are a terrible idea to waste time on "designing".
That said, ventilators I believe are already a solved problem for COVID. We have tens of thousands in the strategic stockpile, and production capacity is being ramped up hopefully to meet demand. This is exactly how these stockpiles were intended to work.
I don't think anyone views them quite as starkly as that.
In the 1930s polio epidemic there was a shortage of "iron lung" respirators, which were expensive to produce. Edward Both invented a plywood version, which was cheap and easy to produce. A re-purposed car factory then churned them out by the thousand.
Is a negative pressure ventilator relevant for COVID-19 treatment? (Any knowledgeable medicos here who can offer a critique?) If so, couldn't they be churned out by the thousand in a short space of time (ie. days)? My understanding is that the tooling is comparable to that used to produce a kitchen cabinet. They can even be manually operated in the absence of a motor or control system.
> While the standard for a conventional ventilator uses a mask or nose tubes and follows current guidelines, the pandemic ventilator is at a standard from the 1970s and requires a patient be intubated, the medical word used to describe putting a tube through someone's mouth and into their airway.
Do intubated patients need more attention from nurses/doctors? It certainly sounds harder then putting on the mask.
How it compares to managing a mask day to day? I honestly don't know, that's something an ICU nurse/respiratory therapist would know.
Source: my sister is a nurse at a hospital treating dozens of COVID-19 patients.
"We're talking about a device that we want to
have available in the worst case conditions and strangely
enough, COVID-19 is not the worst case envisioned," he
said.
Perhaps in 3, or 5, or 20 years....
Maybe we'll be thankful that COVID-19 was sort of a "training wheels" pandemic... something that helped to prepare us for the even worse pandemics that are sure to follow.
Deaths due to COVID-19 will be staggering, but it's somewhat mild as far as possible pandemic scenarios go. Imagine if it had mortality rates comparable to ebola, TB, etc.
When this blows over, the world should be better prepared for the next one, with better procedures.... emergency stockpiles of ventilators, masks, etc.
(Or at least we will be... until we go ten years without a pandemic... and all those stockpiles get liquidated in order to help some politician to balance a budget or whatever...)
No one goes to work with a mild case of Ebola.
HIV/AIDS, several hepatitis variants, and tuberculosis approach thiS, as might syphilis in earlier times.
Kyle Harper's The Fate of Rome explores the notion that new diseases don't simply emerge, but co-evolve with their host populations and environments. The implications are disturbing.
https://lareviewofbooks.org/article/how-the-environment-topp...
This is the first world pandemic in a hundred year, why should it become common ?
(I'm not a doctor and my only source of knowledge on this is other hacker news comments)
IANAD, but it's not just a problem of matching people in the current pool. You also have to plan for incoming patients. Having the parameters of the ventilator not perfectly match the patient likely affects the probability of survival in a smooth way (with in some bounds).
So now the problem becomes minimizing the total death by maximizing the average likelihood of survival. You have to take the patient ventilator parameters into account (tidal volume, lung-compliance, weaning, etc) , as well as information about the distribution of those likely to be sick at the same time (which will change over time based on behavior).
For example, if one could hypothetically spray alcohol everywhere inside someone's lungs, would that kill the infection?
If so, could a liquid/gas mixture be developed to deliver the right virus-killer substance directly to the lungs?
Does anyone here know about PFCs-breathing treatments?[0]
0: https://www.realclearscience.com/blog/2019/08/15/can_humans_...
Thank you to the people that took the time to answer the question and explain why these ideas are not currently feasible.
In a diffuse infection a patient begins to lose both lung area (due to shunting) and the thickness of the diffusion barrier increases (due to inflammation). To help overcome this you want to increase pressure and oxygen concentration.
An iron lung helps ease the work of breathing by reducing thoracic pressure and thus creates a larger pressure gradient for inspiration. However, it does not cause an absolute partial pressure of oxygen change compared to the atmosphere.
Unfortunately, to bind haemoglobin in physiological lung conditions we need partial pressure of oxygen around 100mmHg. My guess is that an iron lung does not help increase the partial pressure of oxygen so it will do little but ease the work of breathing (which is better than nothing!).
Would that accomplish the same goal as a ventilator?
I think people who are actually working on ventilators should seriously consider going for a simpler design .. it might be this or might be something else. The person in this article also said he is happy to give the design away.
I think if the Malaria Med+Antibiotics treatment from the French study don't work (we'll know in about a week I think), we need to move to a war footing and start producing ventilators. My back of the envelope math has scared the crap out of me (best case 500K Canadians dead, worse case 3 million).
I really hope someone who can make a difference sees this.
I've left some comments here on the possibility of doing lung clearance in the absence of sufficient numbers of ventilators:
https://news.ycombinator.com/item?id=22640905
I don't really care to argue it with anyone. Please go find somewhere else to vent your spleen about how stressful this is. My recommendation is and has always been: If you have no other option and you are going to die because of it, you can try this.
That's it. That's my entire point. All the accusations that I'm up to something nefarious and dangerous are completely unfounded.
Take care. Try to not stress too much. Thank you for trying to be part of the solution.
We should assume they won't work. War footing time is now.
10 "in stock," $3,124.01 each.
There's also another model MCV200, 10 "in stock," $5,091.71 each.
Anyone got $95 grand lying around?
Edit: btw, in 2006/2008, the AARC recommended to the White House and/or HHS to buy 10k additional ventilators for the SNS, but the govt failed to do so. Now, the US, is for lack of better adjectives, royally-proper fucked.
https://www.aarc.org/wp-content/uploads/2018/08/issue-paper-...
Also put that in context with the fact that Italy reported that the majority of death is with people which have preexisting conditions/other illnesses.
War time devices must be simpler (easy to make and do field repairs on). We just need the first one.
We are all rooting for your sister.
If we get way more machines but those machines require a lot of intensive monitoring we could wind up with plenty of machines but not making any progress on the fatality rate.
1.Montreal offers $200k prize for cheap and easy to build ventilator design - https://news.ycombinator.com/item?id=22637540
2. https://app.handelsblatt.com/unternehmen/industrie/medizinte...
3.https://www.srf.ch/news/schweiz/knappheit-wegen-coronavirus-...
The struggle to ramp up production is a desperate one, and this is one case where IP is killing people - there are several consortia in the UK that are ready to manufacture, but need a certified design they could build.
I think we probably agree that industrial production is the way forward, but the numbers are not particularly comfortable.
There are only 96,596 ICU hospital beds in the United States according to the AHA. As I said, ventilators are already solved to the point that something else is the bottleneck.
Supply chains take a long time to spin up.
Why not both?
More prosaically, I think I've reduced durations of basic colds by deliberately coughing early on. Needs more experiments, but as you said side effects are minimal, so you may as well try. I'm starting to think this is a family of life hacks that should be much more widely known.
It was a brief reference without enough details to be sure that he was referring to clearance methods similar to our the same as what you reference, but it sounds as if this may be part of therapy already. So well in line with what you have described.
The interviewer suggested this is a different policy from what is happening in the UK/English-speaking world where they/we are basically begging for more ventilator capacity.
Best wishes to you and your family in these trying times.
This isn't quite true.
Taiwan, Singapore and S. Korea have not 'shut-down' their economy, and they have tamed the problem.
Massive and widespread testing, assertive isolation and tracking of individuals who test positive can work on some level.
Combined with some other things like maybe keeping 'big gatherings' or 'social gatherings down', requiring people to wear masks on trains, busses, airplanes - we may be able to reasonably suppress Corona without a medical discovery.
I bet you could find five or more recent peer reviewed studies on it working quite well.
You realize most science isn’t double blind, right? I’ll grant you thats it a gold standard for long term drug use but saying “totally unclear it will work” is absurd.
And we still do useful work relying on simple correlations, r values, peer review. We have all that now supporting some of these drugs. In a crisis and last resort that seems like plenty.
Here's a recent review: https://www.sciencedirect.com/science/article/pii/S088394412...
They find hundreds of relevant-sounding papers, registered trials, and guidelines, but almost no data beyond one in vitro study to back it up. That one study is promising--and it'll be great to see what the trials show--but the road from "works in a dish" to "drugs for all" is a long, bumpy one at the best of times.
We need to do this right so that if it works, we know that it works, and if it doesn't, we can make informed decisions to do something else.
That's nice, but most science isn't reproducible at scale. We need to do a drug trial for SARS-CoV-2 because we need to 1)establish efficacy and 2) establish safety for this drug in this disease. There are a significant amount of adverse drug effects in individual infectious diseases. Jarisch–Herxheimer reaction when treating syphilis, epstein-Barr mononucleosis and penicillin; Reye syndrome with Aspirin and influenza. The list is long here. We want the most vetted research possible because even if the chance of death is less than half a percent, half a percent of what seems like is going to be over a million is going to be in the tens of thousands here.
Furthermore, there is a difference between observations of aggregate numbers, like the number of people on ventilators and their survival rate, and small numbers of uncontrolled drug interventions where there are obvious ways for the data to be deceiving. Not all observed data has the same reliability.
So standard pressure at sea level is 29.92inHg, a 737 MAX can sustain 39k ft altitude indefinitely I suppose, where the exterior air pressure would be 7.66inHg. The cabin is normally pressurized to the equivalent of 8k ft, giving 26.63inHg. The fuselage could withstand a pressure differential of 26.63inHg - 7.66inHg = 18.97inHg (at least, possibly more).
That’s 63% higher than regular pressure at sea level. Not bad.
If you gave each patient a full economy row, that’s about 60 patients per plane, so 48k patients across 800 grounded 737 MAXs.
If the latter, how does it work on airplanes with needless engines?
There are cabin pressurization test carts for use on the ground, as well as start carts to provide bleed air for starting engines, and bleed air in turn can supply cabin pressurization in flight, although this probably requires some rigging on the ground.
Interestingly, they switched to electric compressors for the 787 [0] because those no longer provide bleed air from/to each engine to simplify the plumbing.
That said, you’re describing a bariatric chamber, and they do exist (they perform surgeries in some).
If your whole body is inside, there is no pressure diferential to inflate your lungs.
Am I missing something?
Novel thought...
Theoretically, yes. The Environmental Control Systems on all our commercial airplanes positively charge the airflow at a nominal Delta P of 9.8 psi and have HEPA filtration down to 10µm, but at $100M+ per 737 MAX, delivery customers highly frowning upon such a practice and not being able to deliver them as a "New" airplanes after contamination, highly unlikely.
The A380 fleet is starting to retire prematurely only after 10 short years of service due to lack of profitability and demand due to COVID-19. Those huge retired Behemoths could serve very well as a quarantine base in remote locations.
Your lungs operate on the principle of differential pressure. During normal breathing, hen the pressure inside your lungs becomes less than that of the surrounding atmosphere, air rushes in to normalize and fill it until they are again equal pressures. Gradually increasing or decreasing the pressure of the atmosphere around you (as on a plane or while diving) does not change the physical difficulty of breathing. It may slightly alter the diffusion coefficients of gasses passing through the membranes in your lungs, but this effect is mild at the pressures you could attain in an aircraft hull (and toxic at higher pressures! [0]).
For this reason, you'll notice in images of people in iron lungs, their heads are outside of the device. This allows those who cannot create negative pressure (due to damaged or paralyzed diaphragms or ribcage muscles) to follow a different path. The pressure outside of their chest becomes lower than that experienced in their lungs, forcing an expansion; in order to breath out, the pressure in the chamber is increased. In an aircraft hull a person's lungs/trachea/mouth would be exposed to the same pressure as their chests.
This of course does bring up the very valid question: What happened to all of the iron lungs after the decline of Polio?
[0] https://en.wikipedia.org/wiki/Nitrogen_narcosis
EDIT: Oh I realize I didn't fully discuss the possibility of using a plane as a hyperbaric chamber [1]. The constraints around this concept also rule it somewhere outside of what I would consider feasible. Aircraft typically use bottled oxygen (I believe the 737M does) or a chemical generator, neither of which can produce continuous oxygen or fill the entire plane with it to high levels [2]. If you were able to outfit patients with individual tanks (which would also have to accommodate for increased pressure), the gains seem mild at best compared to 100% O2 in a hospital setting. Fick's Law for the membranes in your lungs is roughly
Rate of diffusion = (Area * Solubility of gas * concentration gradient) / (membrane thickness * sqrt(molecular weight of solute))
The factor that increasing pressure would modify is the solubility of the gas, which according to Henry's Law [4] is directly proportional to pressure. At absolute best (100% O2 on the plane at 2atm), you could expect to get 2x improvement in blood oxygen saturation. Unfortunately I don't believe the breathing issues that are being described can be overcome by this strategy. It's an incredibly creative concept though!
[1] https://en.wikipedia.org/wiki/Hyperbaric_medicine
[2] https://en.wikipedia.org/wiki/Emergency_oxygen_system
[3] https://clinicalgate.com/gas-exchange-between-air-and-blood-...
Take out the seats, equip the cabin with ventilators, and when one outbreak gets under control, send the aircraft to the next outbreak zone.
They even have their own generators lol.
Not sure if this is supposed to be better. And who would fly all these people? Access to the cockpit is through the rest of the plane.
Planes are horribly cramped and if you filled every seat you would be violating social distancing while filling them with sick people.
I can think of a few other criticisms, but those are probably the most defensible concerns.
Covid19 is not the only germs they will be carrying. The people who are the sickest are the ones that most need oxygen supplementation. Reports suggest that most of the people dying from it already have other serious medical conditions.
This is exactly how antibiotic resistant infections get bred. You would be creating a melting pot of horribleness and cross-contamination and god-knows-what would come spewing out of it.
Any changes you could think of that would make it work?
Also, considering Boeing was anticipating FAA approval within weeks, it's fair to assume that the MCAS problem has been resolved. (https://www.reuters.com/article/us-boeing-737max/boeing-737-...)
If it were truly necessary, you could also set up an airtight septum to separate the contaminated part of the aircraft from the front part that includes the cockpit. There is an aft door (as well as emergency exits) that can be used to access the rear of the aircraft.
It just has to fly handful times, from Boeing park lots to a depot in a desert and back from frontline after months/years. They are supposed to be clean before deployment, and can be cleaned by medical professionals before reflying. Or maybe cracks would develop and can't be manned after anyway, either way not much there is in terms of infection risks.
