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by DoreenMichele 2254 days ago
This is the pertinent detail as to why some doctors are concerned:

Generally speaking, 40% to 50% of patients with severe respiratory distress die while on ventilators, experts say. But 80% or more of coronavirus patients placed on the machines in New York City have died, state and city officials say.

1 comments

Could that not be because of shortages? If there's a shortage of ventilators then only the very sickest patients will get them. Don't see how it's valid to compare numbers against disease in "peacetime".
I don't know.

But another concern is that ventilators are known to cause lung damage (because of the high pressure involved) and are typically only used for a day or two with most conditions. With this, people are being kept on them for a week or two in many cases.

So it's not unreasonable to assume that unusually long-term use of a protocol known to harm the lungs is actively creating problems for patients.

>ventilators are known to cause lung damage (because of the high pressure involved) //

I only know a little from my reading in the last month or so, but ventilators (used with intubated patients) seem very adjustable: you can alter the pressure, the Oxygen percentage, the tidal flow, breathing rate and such. I can see that in order to increase blood Oxygen uptake you might use higher pressures, but surely that's necessary to ensure patients get sufficient oxygen to avoid brain damage or other deleterious effects?

Won't the patients suffer in other ways if the Oxygen delivery is lower pressure?

When multiple patients share a single ventilator I see there are issues of balancing the supply, but I don't think that's what we're considering here.

Someone linked me to this a few days back:

https://www.youtube.com/watch?v=okg7uq_HrhQ

It explains how they pressurize the lungs to try to keep the alveoli open and why that's very problematic, even when it is only short term. It is so problematic, they sedate people on ventilators so they won't pull the tubing out.

It sounds just really gruesome and like a brute force method that can't help but cause serious problems for delicate tissues if you use it for more than a fairly short period of time, which is the norm but is not how it is being used for Coronavirus cases.

Oxygen delivery is a complicated thing and I think taking a mechanical approach when mechanics may not be the actual problem is likely misguided.

That's a fair point: another angle to the same issue is that not all ventilators are equal. Under normal circumstances a patient gets intubated and goes on the presumptively most reliable machine the hospital has and is cared for by the people who have the most experience managing these cases and devices. When the hospital fills up, you get whatever junk the hospital can get working and are attended by nurses and techs pulled in from other departments.

That's a reasonable hypothesis, I think. But yeah, we just don't know. And it may be years before we do. No one has the ability to do a controlled study right now.

(Edit: it's absolutely infuriating to see the comment to which I'm replying here grayed out from downvotes. It's a completely reasonable notion phrased as a question, yet HN... doesn't want to hear the answer?)

(Edit: it's absolutely infuriating to see the comment to which I'm replying here grayed out from downvotes. It's a completely reasonable notion phrased as a question, yet HN... doesn't want to hear the answer?)

You're right and I've given it a corrective upvote. For a time, I had a PSA in my profile indicating that I think downvotes will be weirder and more hair trigger during a global pandemic. I'm trying to be more thick skinned about weirdness happening in votes on my own comments, but, yes, it's just adding sand in the gears at a time when we don't need more noise.

It could also be that too many people not requiring ventilators are put on it. Ventilators are machines that can do significant damage. It's a machine of last resort.

There is a reason why 80 to 90% of doctors would refuse ventilators for themselves.

https://io9.gizmodo.com/your-doctor-probably-has-a-dnr-heres...

It could simply be an outlier or maybe defective machines or anything really. We don't know and we'll have to wait until the dust settles and we get more data.