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Risky hack could double access to ventilators

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Re: Risky hack could double access to ventilators

#11

Post by liquidify »

They kept giving reasons why this might not work...

  * not tested in humans
  * cross infection potential
  * different sized people mess it up
... but I see no reason why any of these things would stop me from using this in the real world. If things are bad enough that we need to do this, then we should be able to find relatively similar sized people. Cross contamination is not a concern when someone is dying here and now and likely has the same disease as the guy next to him who is also dying. Priority 1 is save them. Make their next of kin sign a waver or something, but save them. Lastly, who cares if it hasn't been "tested"? It was used in the real world, in a real life and death scenario, and it worked. I'd absolutely take my chances with it given that the failed option is to pull people off and set it back to single person mode. At least try.

Lastly, I would imagine that some common pressure regulation values could be used to compensate for different sized people.

Re: Risky hack could double access to ventilators

#14

Post by tathougies »

liquidify wrote: post #11

They kept giving reasons why this might not work... * not tested in humans * cross infection potential * different sized people mess it up ... but I see no reason why any of these things would stop me from using this in the real world. If things are bad enough that we need to do this, then we should be able to find relatively similar sized people. Cross contamination is not a concern when someone is dying here and no…

> Cross contamination is not a concern when someone is dying here and now and likely has the same disease as the guy next to him who is also dying

If COVID evolves into multiple strains, then there is a real risk of cross-infection that would make the immune system forced to work harder? Moreover, a lot of the pneumonia deaths are not due to covid itself but rather due to opportunistic infections (often bacterial) that end up causing the pneumonia that causes death. Letting two COVID patients share a ventilator could mean that now one is exposed to a novel bacteria in the other that causes them to develop pneumonia.

Re: Risky hack could double access to ventilators

#15

Post by nathanlied »

Polylactic_acid wrote: post #10
grej wrote: post #7

Earlier quoted context omitted.

Depends on whether you flatten out the growth rate. It won't/can't keep growing like that when everyone is sheltering in place.

Seems likely. Italy is currently seeing a 13% increase per day while the US is now very close to a 50% increase per day. There are news reports showing beaches and bars in the US are still fully packed. It probably relates the US culture of disregarding expert advice and doing the opposite to "own the scientists"

It's not just the US. This happened across countries in Europe as well; Italy had it happen, Germany had "Coronavirus Parties", even. It happens because some people are idiots, and others aren't quite aware of how serious the situation is.

Once reality sets in, only the absolute idiots that don't care for being socially ostracized (or in some cases even legal consequences) will continue that behaviour. And luckily those are normally a minority.

Re: Risky hack could double access to ventilators

#16

Post by mlyle »

liquidify wrote: post #11

They kept giving reasons why this might not work... * not tested in humans * cross infection potential * different sized people mess it up ... but I see no reason why any of these things would stop me from using this in the real world. If things are bad enough that we need to do this, then we should be able to find relatively similar sized people. Cross contamination is not a concern when someone is dying here and no…

It's not exactly "different sized people mess it up". It's not just different lung capacities, but different lung compliance-- which also changes over the course of disease.

Most simple pressure regulators will not fare well in the environment, either, because of the bidirectional flow, etc.

The "Y" hack definitely has use, but finding matches and keeping patients matched definitely means we will only be able to use it sparingly.

Re: Risky hack could double access to ventilators

#17

Post by russdill »

liquidify wrote: post #11

They kept giving reasons why this might not work... * not tested in humans * cross infection potential * different sized people mess it up ... but I see no reason why any of these things would stop me from using this in the real world. If things are bad enough that we need to do this, then we should be able to find relatively similar sized people. Cross contamination is not a concern when someone is dying here and no…

Coronavirus destroys lung tissue and weakens the immune system. Then bacteria move in. It's the bacteria that cause the pneumonia. Different people will likely have different bacteria in their lungs.

Re: Risky hack could double access to ventilators

#18

Post by pzlarsson »

609venezia wrote: post #6

I thought I remembered reading somewhere recently that 2:1 is already in use in some cases (maybe in Italy?), but I can't find a source. Is there increased risk of ventilator failure with this approach? That seems like it could be an additional terrible factor to weigh, because parts have become so scarce.

The 2:1 setup was used to save lives after a mass shootings in Las Vegas a few years ago. They paired patiets of similar size, put them on the same ventilator and double the flow rate.

It was mentioned in a blog post by an ER physician linked from hn back then.

Re: Risky hack could double access to ventilators

#19

Post by theturingnerd »

bitexploder wrote: post #3

This is really neat. It seems a lot of the risk is how specific lung capacities and conditions interact with the ventilator and how much oxygen someone needs. My question to any MDs reading this: how often do you have to tweak ventilator volume for patients using one? What is the feedback loop? Blood oxygen levels?

(physician here) Vents can be quite tricky to get right; primarily because as disease progression continues on many things change. We are always trying to balance the deleterious effects of the intervention (in this case, the vent) with the goals of care.

What most people don't know is that vents cause a lot of injuries on their own. (See ARDS). Hypoxemic respiratory failure is serious stuff, and it's almost always not the only insult we're dealing with. So, it's about balance.

In the feedback loop is a lot of things. Certainly, oxygen saturation is a core measure, but we are also thinking about things like hypercapnia (and acidosis); overall perfusion status (blood circulation); infection management; etc.

Gas exchange is important, but there are a lot of things that have to go right for the lungs to take oxygen in, get it into the right transport, and get carbon dioxide back out. You can over-optimize for any of those at the expense of the other (see: hypercapnia).

In short, it's complex and there isn't a solid formula that will work for every patient. It's actually the subject of a lot of debate on details (some of it quite passionate in our Critical care / pulmonology community). This is why we call it PRACTICING medicine ;)

Re: Risky hack could double access to ventilators

#20

Post by djsumdog »

theturingnerd wrote: post #19
bitexploder wrote: post #3

This is really neat. It seems a lot of the risk is how specific lung capacities and conditions interact with the ventilator and how much oxygen someone needs. My question to any MDs reading this: how often do you have to tweak ventilator volume for patients using one? What is the feedback loop? Blood oxygen levels?

(physician here) Vents can be quite tricky to get right; primarily because as disease progression continues on many things change. We are always trying to balance the deleterious effects of the intervention (in this case, the vent) with the goals of care. What most people don't know is that vents cause a lot of injuries on their own. (See ARDS). Hypoxemic respiratory failure is serious stuff, and it's almost always n…

What do you think are the risks of cross contamination in this setup (let's say, just for 2 people sharing one unit)? She mentions how, in a situation where you'd have to use this, they'd have the same infection. What if they have different secondary infections or different types of pneumonia?

The example of the Vegas disaster is different because they were all gunshot victims; they were healthy, but wounded. I hope we would never need to see if these would be effective.

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