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Researchers complete first human trial on viability of enteral ventilation

timerol

I really expected this to be overblown clickbait, but the article delivers on the title about as well as it could. I have seen many more breathless articles on treatments that weren't already conducting human safety trials as well as having animal effectiveness trials concluded.

And yeah, it turns out that mammals can absorb oxygen through their butts. Weird

imglorp

Some reptiles too. Painted turtles can survive under winter ice for months with cloacal respiration to extend their hibernation.

https://www.pbs.org/newshour/science/the-secret-to-turtle-hi...

xnx

> breathless

I see what you did there.

foxyv

I know that rectal rehydration is a good method when sterile IV fluids are not available. Hopefully it's much safer than current ventilator or ECMO treatments.

leoh

Not really. Said tissues are well vascularized and therefore lend themselves to oxygen exchange. It’s just that the lungs are especially efficient for this.

0cf8612b2e1e

Supposedly end stage alcoholics will give themselves alcohol enemas to more readily absorb the alcohol. More direct exposure to the veins.

Which sounds like a fake urban legend, but I would never discount want an addict is capable of doing.

agobineau

it pretty common. a lot of people in my high school did this, or froze beer and inserted it to get rapidly wasted. the other classic is the tampon soaked in vodka

most of this was just done because drinks were too expensive or hard to get for high schoolers and they had to optimise their alcohol supplies

pontifier

My mother is currently dying in the hospital with breathing problems. I mentioned this to her earlier today... I thought this would have been much farther along than it is. Hurry up with the medical tech already!

radu_floricica

I wonder:

- what's the actual oxygen carrying capacity? If they're up to human trials then I imagine they've already validated this step in animals

- can it also scrub CO2?

Without doing more research, I'm putting most of the probability mass into it being be a small but significant oxygenation aid. Not enough to let us survive without working lungs, but enough to push the odds in emergency situations, while also being harmless. Something like 5% extra survivability for a $100 cost and a sore butt. Well worth it, but not a revolution.

Tade0

CO2 dissolves really well in Perfluorodecalin.

EDIT: I mistook solubility of oxygen by volume for that by mass - very different figure and of course effectively much lower.

AnonC

The answer to the most important question is at the end of the article. They demonstrated that this is safe, not that it’s effective.

> “This is the first human data and the results are limited solely to demonstrating the safety of the procedure and not its effectiveness,” said co-author Takanori Takebe of Cincinnati Children’s Hospital and the University of Osaka in Japan. “But now that we have established tolerance, the next step will be to evaluate how effective the process is for delivering oxygen to the bloodstream.”

If it’s proven to be effective and can help avoid ventilators for (at least some) people, it would be a huge breakthrough and improvement in the quality of life for the patient and for their close ones.

polishdude20

I wonder if, given that our intestines can absorb gasses into our blood stream, if that also means we readily absorb our farts into our blood stream as well? The chemical composition of them could be having effects on your whole system maybe?

russdill

hn_throwaway_99

Worth the risky click, that was surprisingly informative.

tomcam

Thank you for your service

thornton

Agreed!

freediver

The answer is probably yes and they eventually get exhaled through the lungs or metabolized by various tissues. Gives whole new meaning to 'carrying the fart' though.

richrichardsson

"Better out than in" might hold some weight if so.

qlm

If this was enough to temporarily replace breathing I wonder how that would feel if you were otherwise healthy. I imagine not breathing would instinctively feel quite strange and even distressing.

goodells

It would be quite distressing because of the accumulation of CO2 in the blood, even with completely adequate oxygenation delivered intrarectally. The slight change in acid-base balance is what makes a person feel the need to breathe, and CO2 is an acidic byproduct of metabolism. This is why people with metabolic acidosis (e.g. in diabetic ketoacidosis or sepsis) have an increased respiratory rate.

eszed

Would CO2 still build up if someone isn't breathing at all? I'm guessing so, since you say CO2 is a byproduct of metabolism. Alternatively, could respiration exhaust enough CO2 even in a situation where the lungs are too damaged to take in sufficient oxygen?

All that apart, I'm guessing this would be used in emergency situations, where a patient is likely already unconscious and could be kept under sedation until transferred to ECMO. Is CO2 buildup dangerous on its own? If so, in what kind of time-frame? What's the upper limit on the additional minutes this therapy could buy?

dillydogg

In my thoracic surgery rotations in med school I was taught that the strongest stimulus for increasing the respiratory drive was the acidification of cerebrospinal fluid. Which, of course, correlates with the blood pH. This information comes from some studies in the 60s with goats, and the old guard are happy to hang their hat on it.

There are also chemoreceptors for oxygen concentration in the circulatory system as well.

I think everything you have said is correct, I just wanted to add a few more details for anyone who is interested.

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hifikuno

From the littlei know from a breath holding workshop I did awhile ago (for trying to get into freediving) it's the carbon dioxide build up in our blood that gives us the urge to breath, and not the lack of oxygen. If this method allowed for the removal of carbon dioxide from the blood then holding your breath might not even be discomforting.

Edit: goodells explained it better!

dillydogg

The acid base balance of the cerebrospinal fluid is the primary driver of the respiratory drive, like allude to with your comment on the CO2. I did want to add that the lack of oxygen can affect respiration, which is detected by the peripheral chemoreceptors, like in the carotid bodies.

Additionally, the thoracic stretch receptors are important for respiratory drive, where the lack of expansion of the chest will promote respiration. When a healthy young person holds their breath for short periods, say 30 seconds or so, their blood CO2 and O2 are not much different, but they still will have to fight the instinct to breathe!

not_a_bot_4sho

I'm scuba certified.

Now I'm wondering if I should get certified to dive with an anal rebreather too.

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belZaah

There was a time, where there were bellows made available along the Thames in London. Because it was believed blowing tobacco smoke up someone’s backside would be a really useful mechanism of resuscitation, in particular in case of drowning. There’s a itsy bitsy kernel of truth in everything…

qyph

I wonder if this could be used for doping in aerobic sports? Could this elevate overall oxygen intake in a healthy person?

My vague understanding is that oxygen intake is a big limiting factor in aerobic activities hence measurement of things like vo2max in sports science. ‘Blood doping’ has similar benefits though it’s also about having more blood period.

It seems unlikely that one could take a big enough suppository to help in a meaningful way in a marathon, but in a middle distance race lasting only a few minutes…

semicolon_storm

It seems unlikely, athletes are consuming liters of oxygen per minute. Plus, the impact is at least partially offset by needing to carry the extra weight with you.

Different story for apnea sports like freediving where a little bit of extra oxygen goes a long way.

o11c

A liter of liquid is a lot more than a liter of gas ...

Liftyee

Isn't liquid oxygen cryogenic (boils at -183C)? The engineering of keeping that ...there... gets interesting fast, especially when dealing with all the cold (absorbed heat from expanding gas) and containing the pressure while also releasing oxygen slowly.

stevenwoo

In a trained person, the limiting factor as I understand it is the capacity of one’s blood cells to carry oxygen to the muscles. This method does not make more blood cells unlike the common doping methods used for aerobic sports like blood doping, artificial EPO.

0cf8612b2e1e

Cyclists have been doping by taking transfusions of their own, previously donated blood. The extra blood cells can then carry more oxygen than a non-treated human.

colechristensen

The surface area of your lungs is like a tennis court, there is a significant difference.

This is being talked about in the ballpark of partial assistance during severe respiratory failure so more like delaying organ damage during a crisis than boosting peak athletic performance.

boltzmann-brain

there's a lot to air and gas within our digestive tract that we don't seem to understand.

one time when i got salmonella, i started reading up on it (believe me, i had nothing better to do) and i postulated a hypothesis: the bacteria starts out being able to (barely) survive in your normal gut biome, but creates sulfur gas in order to thrive, and then once it does, losing that atmosphere kills it.

so i started swallowing massive amounts of air, and laid down so that my head was the lowest point of my body. low tech? yes. stupid? who knows. but i was feeling better on the next day - and normally it takes a week or two to clear out.

n=1, take it with a lump of salt. hopefully sharing this helps someone in some way in the future.

smcnally

> The technical term is enteral ventilation via anus (EVA).

Anecdatally, I have encountered multiple people with congenital capabilities re enteral locution via anus.

Wishfully, training astronauts for enteral ventilation via anus during extravehicular activities that involve writing an ongoing Prince song would be called “EVA EVA 4EVA.”

p0w3n3d

It somehow resonates in me with one of the first memes I was sharing

  Do you think that's air you're breathing now?

MathMonkeyMan

For those unfamiliar with this piece of internet history: <https://www.youtube.com/watch?v=twpdnV2Yq1E>