>Intra-rectal delivery of a liquid form of O2 known as conjugated perfluorocarbon, a compound historically used in clinics for liquid ventilation through airway administration, is highly tolerable and efficacious in ameliorating severe respiratory failure. Thus, by repurposing the distal gut as an accessary breathing organ, enteral ventilation therapy offers an alternative paradigm as an adjunctive means to patients who are in critical need of respiratory support.
Nitpick (on TFA): perfluorocarbons are not "a liquid form of O2". The thing about these liquids is that they can dissolve a huge amount of both O2 and CO2, compared to normal liquids. It's kinda crucial that they can carry lots of CO2 out of the body as well.
Calling PFCs "a liquid form of O2" is like saying carbonated water is "a liquid form of CO2".
I wonder what it would take to get us to the point where we can oxygenate sufficiently without needing to use our lungs at all. Tons of applications there.
As seen in The Abyss (1989), where a real rat was submerged in a similar liquid. Of course, its respiration was not rectal, but normal – or as normal as "breathing via liquid" can be.
The joke here is "Man next year's scuba gear is going to be really interesting."
That said, the paper using the liquid EVA (L-EVA) technique can keep rodents survivably oxygenated. (~ 95% oxygen levels if I am reading the graph in figure 2C correctly) so it is an interesting result to watch.
It looks like this works for oxygenation, but does it work to remove carbon dioxide? I didn't see anything about that in the paper, but it's just as important unless it's super short-term.
"Interestingly, the arterial pressure of CO2 tended to be decreased in the l-EVA group, presumably due to the excellent O2 - and CO2-carrying capacity of perfluorochemicals (50 mL O2/dL and 160–210 mL CO2/dL, respectively), while the arterial pH did not change in our experiment. These results indicate that perfluorochemicals also act as an adsorbent for elevated CO2, indicating a need for future follow-up studies of gas exchange mechanisms."
David Blaine claimed that when he was preparing for his underwater breath holding record attempt, he bought some of this stuff online thinking he might be able to just cheese it.
So he filled his sink with it, stuck his face in and tried to breathe.
He found it so difficult and unpleasant he decided to just break the record for real instead (he got 17 minutes and 4 seconds).
This is a fascinating discovery, but I do want to spare a moment's thought for the lab animals in the study. Asphyxiation is a deeply unpleasant way to die, which is what happened to all of the control group, all of the group without intestinal abrasion, and 25% of the mice who were given the full treatment.
That latter is just one animal; the groups were very small. But that sounds especially horrible, getting almost enough oxygen to live. Every single animal underwent "agonal respiration", which is merely medical Latin for "gasping for breath", but nonetheless suggests that these mice were suffering substantially.
I'm glad that the groups were small. I'm well aware that animal models are necessary for medicine, and that these deaths may well one day save many human lives; presumably the Institutional Review Board decided it was worth it on balance. I hope that future experiments can continue to be done with an eye to minimizing the suffering that goes into them.
It's good that you brought this up in a tactful way. I share your concerns about animal suffering, and your hope for the future.
It sounds like you are willing to concede that the suffering in this particular case is potentially worthwhile, and I too am willing to make this concession. Millions of people have died, and we have to do what we have to do. I hope we can be smarter in the future.
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[ 0.21 ms ] story [ 104 ms ] thread>Intra-rectal delivery of a liquid form of O2 known as conjugated perfluorocarbon, a compound historically used in clinics for liquid ventilation through airway administration, is highly tolerable and efficacious in ameliorating severe respiratory failure. Thus, by repurposing the distal gut as an accessary breathing organ, enteral ventilation therapy offers an alternative paradigm as an adjunctive means to patients who are in critical need of respiratory support.
Calling PFCs "a liquid form of O2" is like saying carbonated water is "a liquid form of CO2".
https://en.m.wikipedia.org/wiki/Electric_bacteria
Imagine using a battery and a small wire to directly enable respiration at the cellular level rather than using oxygen at all.
I can see this greatly facilitating a host of activities on other planets or in space.
https://www.youtube.com/watch?v=oFFpMqs9kbI
https://youtu.be/TIGCdA2YLyY
That said, the paper using the liquid EVA (L-EVA) technique can keep rodents survivably oxygenated. (~ 95% oxygen levels if I am reading the graph in figure 2C correctly) so it is an interesting result to watch.
Once there was a hedgehog who had learned to breathe with his butt. One day he sat down onto a tree stump and died of suffocation.
But seriously, if my lungs had to go and I had an option, I would totally grab at any tech to breathe with my whatever else.
"Interestingly, the arterial pressure of CO2 tended to be decreased in the l-EVA group, presumably due to the excellent O2 - and CO2-carrying capacity of perfluorochemicals (50 mL O2/dL and 160–210 mL CO2/dL, respectively), while the arterial pH did not change in our experiment. These results indicate that perfluorochemicals also act as an adsorbent for elevated CO2, indicating a need for future follow-up studies of gas exchange mechanisms."
So he filled his sink with it, stuck his face in and tried to breathe.
He found it so difficult and unpleasant he decided to just break the record for real instead (he got 17 minutes and 4 seconds).
https://youtu.be/XFnGhrC_3Gs?t=297
That latter is just one animal; the groups were very small. But that sounds especially horrible, getting almost enough oxygen to live. Every single animal underwent "agonal respiration", which is merely medical Latin for "gasping for breath", but nonetheless suggests that these mice were suffering substantially.
I'm glad that the groups were small. I'm well aware that animal models are necessary for medicine, and that these deaths may well one day save many human lives; presumably the Institutional Review Board decided it was worth it on balance. I hope that future experiments can continue to be done with an eye to minimizing the suffering that goes into them.
It sounds like you are willing to concede that the suffering in this particular case is potentially worthwhile, and I too am willing to make this concession. Millions of people have died, and we have to do what we have to do. I hope we can be smarter in the future.