/sci/ - Science & Math

SKUNKWORKS, COME BACK AND RAM YOUR PENIS UP MY ASS. HARD.

>>1569326
Just stop, man. It isn't funny. "Oh look at me, I can use a trip code someone else spent 3 days trying to break"
Fuck you, its not funny

>>1569326
>>1569338
Holy crap, both of you got my trip wrong.

Are you even trying, fucking 0/10 trolls?!

>>1569338
Actually it took about 15 minutes.

>>1569338
>>1569326
Speaking of that, it would be fascinating to keep limbs alive on ECMO away from their body. Damn I'd love to test it on you douches :-P

Anyway serious thread, give serious answers.

You guys sure are slow readers...

Hurry it up and I'll post some poontang for serious responses.

Ok, I will admit a Flesch Reading Ease of 27.75 is probably above most of you, let alone the contents, but /sci/ is supposed to be smarter than this.

>>1569400
I hate to break it to you, but people with enough intelligence to comprehend your idea are few and far between on /sci/. I suggest you take a look at "SciChan" if you would like to engage in actual discussions. That being said, this sounds rather plausible.

Bumpin'

So what you're saying is that we should amputate limbs with gangrene, artificially move blood and oxygen through the limb, then reattach it once the infection has cleared up, because the leading cause of death due to gangrene is a lack of blood flow and oxygen?

If that is what you're saying, you might be on to something.

>>1569833
No, no, no, no and no.

I'm saying you should disconnect the major veins and arteries in the limb from the body, and use ECMO to keep the limb alive BEFORE it becomes ischemic enough for gangrene to set in.

>>1569851
And in the case of multiple limbs, simply run shunts from limb to limb that all hook up to a single ECMO, probably in parallel.

>perfuse blood
>ischemic

Perhaps I'm out of my waters here. Let me get this straight: we disconnect the arm, keep it artifically "alive" in another way, and wait for the gangrene to go away? In any case, when does gangrene just get up and walk away?

Ah, okay. Makes sense to me. Which is a miracle, because I'm not even in college.

If that is the case, it could very well work. Congratulations, now go share your idea with the world!

>>1569875

What he is saying is that the major cause of gangrene from meningitis is that blood can not reach the limbs in an adequate amount because the heart is not strong enough. By amputating the limbs before gangrene sets in, the blood can be moved in them artificially until the meningitis clears up and the heart is able to pump blood through the limbs as normal.

>>1569881
Yeah, gangrene only sets in after tissue has died.

That's why it is so critical in my idea to study bloodflow with doppler ultrasound, and find the correct time to intervene when it is apparent that the body is no longer perfusing enough blood to the limbs to keep them viable, and then operate to disconnect the blood vessels and switch to ECMO at that point.

There is really no need to amputate the limbs, and replantation brings in a whole new set of complications and functional downgrades. The limbs would be left in place and simply isolated from the rest of the body's circulatory system.

Still looking for more opinions from /sci/'s few medfags

>>1569901
Although the idea isn't to amputate the limbs, see >>1569917

The idea is just to leave them in place, but isolate them from the rest of the circulatory system and keep them alive with ECMO.

Well, it sounds like an incredibly invasive treatment, specially with regards to the brachial artery, and the chances of fucking up are through the roof, but since at that point it's "try this or get gangrene"...

Hmmm. I'm liking your idea, brosephus. I have to give it some more thought. What about nutrition to the now "isolated" tissues? Since you're proposing ligating some main veins and arteries.

What the fuck is this post doing sliding off the first page. /sci/, I am disappoint.

>>1570013
I don't know that much about keeping tissue alive "in situ", but I'd think it's possible with a specialized IV mixture.

>>1569311
In technical writing, sometimes we hyphenate tedious adjectives to increase readability. Example

>>So gangrene due to bacterial meningitis is, to my knowledge, the leading cause of non-traumatic, bilateral, upper-extremity amputation, which is obviously a fairly devastating disability. Because the cause of gangrene in this case is prolonged poor perfusion of soft tissue in the limbs (ischemia)....

bumpin'

Well it sounds invasive as fuck but as a last resort I suppose it makes sense.

Also, bumping for actual /sci/ on /sci/.

>>1570366

>>1570086

Oh man, all my practical experience with keeping disconnected tissues alive has been in petri dishes, what with my field of research going in a completely different direction.

What I can tell you is that it's not so difficult to mantain human cells happy for a little while, but the slightest of changes will fuck their shit up right away, so you want to make sure the mixture you're feeding them is closely watched at all times. I don't think it'd be as easy as plunging in an IV drip and then letting the body do its job, because the limbs are heavily dependant on the torso (duh) and if disconnected you're gonna have to do everything the body does for them yourself. That means mantaining the right chemical enviroment, the right temperature, handling nutrient distributions and waste disposal. Oxygenating is a big part of it, yes, but not the only one. I don't think its impossible, though. You might be onto something.

>>1570702

Instead of severing the limb and doing all that, couldn't you just bypass the non-functioning blood vessels with a H-L specc'd to just pump blood? You could tap an artery with one end and run the other end into an artery in the limb, letting fresh blood get through.

This is less invasive, less expensive and much less dangerous than your idea.

>>1569311
it sounds like they already do this, or if they don't then it would probably work:
from wikipedia:
>The best treatment for gangrene is revascularization (i.e., restoration of blood flow) of the affected organ, which can reverse some of the effects of necrosis and allow healing. Other treatments include debridement and surgical amputation. The method of treatment is, in general, determined depending on location of affected tissue and extent of tissue loss.

<<pic also from wiki. first time i have seen a pic on wiki worthy of being in a gore thread on /b/,

>>1570865
I think that limb is beyond recovery. And is likely filling him full of nasty toxins. He'd be better off hacking it off with a dirty cleaver in the mud.

>>1570836
Again the idea is not to severe the limbs, just to severe the blood vessels.

>>1570865
Yeah. And eww.

>>1570871
Or at least damn close.

Normal Person: Sounds like a good idea.

Doctor: Sounds like a good idea.

Consultant: Sounds expensive.

>>1570871
>>1570906
Is that painful at all? I mean I think it would be, yet he's standing and shit...

>sound interesting
>go to Wiki to read up on subject
>read about Fournier gangrene
>my fucking visage

>>1569311

yes, yes, we're all very impressed with your knowledge of anatomy and ability to spell.

>>1569400
>Flesch Reading Ease

here's where it's made obvious that you want to impress.

i'd say fuck off, but i do believe that /sci/ is the only place sufficiently layman to somewhat-grasp what you're saying and not completely ignore you.

>>1571040

I'd much rather have /sci/ flooded with threads like this one instead of "PROVE GOD DOENST''' EXIST U CNAT' FAIL!"

And come one, nothing they wrote was hard to understand and it's an interesting topic.

>>1570865

On an unrelated topic, Jesus fuck I'm glad I only work with little cells and microscopes.

bumpin'

>>1569311
The fuck you need something so drastic so early in your diagnosis?
IF you detected extended poor perfusion to the limbs wouldn't it be simpler to treat these cases with pharmaceuticals? I am not a specialist in the circulatory system, but seems much more realistic to design suitable vasodilation drugs and couple these with localized delivered oxygen. Prehaps something as easy as NO inducer doped oxygenated blood transfusion delivered locally to the affected limb...

Just a thought.

>>1572880
I think the problem with vasodilation is that cardiac output is too poor, you may end up killing the person due to hypotension.

Perhaps hyperbaric oxygen therapy would be a good treatment to try before moving to something more drastic like ECMO. The idea would be to only put the person's limbs onto ECMO when their getting so poorly perfused that there's no doubt that they'll start to run into tissue death in short order.

>>1573130
>cardiac output is poor
>>1569311
>disconnect the arteries and veins, cauterize them together

This sounds like it will be full of fail... if the cardiac output is poor surely a cocktail of pharmaceuticals (include some adrenaline or some other shit to increase output) would still be preferred. I am just thinking that if I had a major infection and was asked to try experimental drugs or high-risk experimental surgery involving the severing of major arterial networks I wouldn't need long.

However, I do give your idea merit as a last ditch, "oh-fuck-we've-tried-everything-lets-cut-it-off" alternative. But realistically, I doubt this will ever be seriously considered as an option.

>>1573485
Well I'm just figuring that if pharmaceutical management were feasible when limb ischemia were severe, there wouldn't be too many people still losing limbs to bacterial meningitis. (pic related)

I would agree my idea is pretty much a last ditch thing, but it would only be used in cases where gangrene is a certainty with any other treatment.

And again, the idea is only to disconnect the arteries and veins, not the entire limb.

bumpin

>>1573517
could you imagine a hand job from her?

>>1574667
lol'd

Comments like this in a thread like this are why I love 4chan.

holy shit bump

Surgeonfag here -

The reason your idea wouldn't work is as follows:

1/ The primary pathology is disseminated intravascular coagulation (DIC) which leads to multiple small clots forming throughout the circulation which then embolise into one-way vascular beds (the skin, digits, retina)

2/ The time required for surgery to isolate each limb would be in the region of 1-2 hours, with a reasonable amount of blood loss at surgery

3/ Anaesthetic drugs themselves can cause blood pressure to drop, resulting in decreased perfusion to already-compromised organs

4/ Gangrene is the indicator of irreversible tissue damage, and amputation is the only cure

5/ Cases of bacterial meningitis that get to this point in the developed world are incredibly rare (simple penicillins kill most causative agents, and we have widespread vaccinations against meningococcus A,C and W135 as well as haemophilus influenza B) and therefore the developed world is where these severe cases occur. And they can't afford ECMOs for premature babies, let alone adults who can be 'cured' by amputation.

Sorry dude, not going to work.

-surgeonfag

>>1575019
>>1574974
I think he said the idea was to start ECMO *before* the limbs were gangreneous!

>>1575041
if they are not gangrenous, then how would you know to start it?

>>1575041

surgeonfag again

Once DIC has set in, there's little you can do save for supportive measures and short-term anticoagulants. Besides, penicillins stop the vast majority of cases (there are only around 2,000 cases of full-blown meningococcal septicaemia in the UK per year).

Anyhoo, just checked out pubmed.org and found http://www.ncbi.nlm.nih.gov/pubmed/15026862 - doesn't sound too great...

>>1574974
>>1575019
Very interesting.

I have thought up a couple counterpoints though, if you're still around tell me what you think of them...

1. Would starting ECMO early enough and using enough heprin prevent very severe clotting?

2. I suppose if you have a team for each limb, this would feasible, if but very expensive?

3.What about using Xenon or some other (what?) niche anesthetic that doesn't cause much hypotension?

4. Again, start ECMO before gangrene or severe clotting, only when it becomes evident that this is where things are heading.

5. True about the rare part (what a few per 100k afaik?), but on the cost point of view, well, fuck. I suppose compared to the cost of rehab, prosthesis, counciling and lost productivity due to permanent disability, this could be worth it though?

I'm aware these five points are rather large flaws, but hear me out! Thanks for the answers.

>>1575041
Yeah, exactly.

I'll try to answer a couple of your points -

There are some anaesthetic combinations that cause little in the way of blood pressure drops, but we're talking surgery on small people here as they're the ones who get this (babies and children <5 or the very elderly). A baby has about 100mL of blood IN TOTAL.

Even 4 skilled teams performing the limb surgery could easily spill that much. And still take 1-2 hours.

The intravascular coagulation is triggered by widespread activation of the 'complement' system of innate immune proteins and I think the heparin only prevents clot enlargement, not their initial formation... :(

Unfortunately, the best treatment is a combination of vaccination and constant vigilence. Even if you're an adult now, you can still be vaccinated against the most common types BTW - I was just a few years ago.

Sorry to burst your bubble :(

However, if medical ideas are your thing - have you considered a career in BioMedical Engineering?

>>1575050
I'd think a combination of some of the following: visual analysis, skin temperature, pulsoximeter, ultrasonic doppler bloodflow and (maybe?) arterial radiography?

Regardless, the idea would to establish when the limbs are most likely "terminal", but still salvageable, and start ECMO at this point.

>>1575085
Eh... yeah.

Could adding hyperbaric oxygen therapy and perfluorocarbon artificial blood product help reverse some of the effects in addition?

>>1575143
Hmm... yeah...

Still a couple more though, what about my idea of starting when limb perfusion is declining seemingly irreversibly, but clotting has not become severe?

And what about perfluorocarbon blood product and hyperbaric oxygen? I'd think both of them would greatly help limb perfusion even if some clotting had already occurred when the limbs were placed on ECMO.

And what about transfusing blood while the person is in surgery to attach ECMO?

And even if this is impractical for newborns and the elderly, what about the rare cases of healthy adults getting meningitis? Could this help them?

>>1575143
Oh yeah also I'm quite interested in Biomed.eng, but I'm an EE major. Thinking of maybe picking it up as a minor.

>>1575207
>>1575162
medschoolfag here, I think your onto something if you do indeed catch it early enough, before disseminated intravascular coagulation has begun

trouble is you sure as fuck don't want to disconnect the blood vessels from a limb for ECMO when there is a chance that it would remain viable anyway, the procedure itself would probably some real risk of losing the limb

>>1575260
interesting... would careful monitoring of bloodflow in the limb be able to establish a point past which all limbs without treatment will become unsalvageble?

Bumpan'

Looking a little doubtful in some scenarios, but I haven't totally given up that there may be some application for some patients...

>>1575520