Rectal Breathing with Perfluorocarbons
cell.com
cell.com
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.
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.
"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."
>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".
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).
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.
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.