4 ms·

dumb question -- is it not possible to just directly oxygenate blood? like what stops having a special IV that takes blood out, oxygenates it, and puts it back

dumb question -- is it not possible to just directly oxygenate blood? like what stops having a special IV that takes blood out, oxygenates it, and puts it back in?

deleted 4y ago
[deleted]
ceejayoz 4y ago
Yes, it's entirely possible; it's called ECMO. https://en.wikipedia.org/wiki/Extracorporeal_membrane_oxygenation https://en.wikipedia.org/wiki/Extracorporeal_membrane_oxygen... It's very risky and requires a nurse at the bedside 24/7, so it's a last-ditch sort of intervention.
- buryat 4y ago
  why is it risky?
  - PeterisP 4y ago
    You need to treat lots of blood continuously, so you have to cut a bypass into the largest, irreplaceable blood vessels, unlike smaller operations like kidney dialysis where you can just "plug into" an arm. Mechanical pumping of blood is a problem as it damages blood cells. Infection is a severe risk. Any break in the operation or a temporary "plumbing issue" where the machine connects with the body can be fatal. So you need 24/7 monitoring capable of really rapid response.
  - tibbydudeza 4y ago
    Red blood cells are meant to travel into capillaries so must deform but will shear easily when subjected to stress which activates clotting action - mechanical pumps still cannot replicate the pumping action of heart.
    - gxt 4y ago
      How has medical science never heard of bellows? https://en.m.wikipedia.org/wiki/Bellows https://en.m.wikipedia.org/wiki/Bellows
      - tibbydudeza 4y ago
        Heart is truely an amazing organ - don't think we will get close to a mechanical replacement. Has multiple chambers, Has chambers that pump sequentially with different pressures and volumes, Never needs to stop for additional lubrication, Never needs to be "charged", Never stops for maintenance, Is powered by oxygen delivered by the red blood cells it is pumping, Is controlled by the body's "proprietary" electro-chemical control system, Is not rejected by the body's internal bio-chemical defense mechanisms, Produces only carbon dioxide as waste, delivers that waste to red blood cells, Doesn't have a single rough or chemically reactive surface, Forms perfect in-line seals around each chamber without crushing red blood cells, Never leaks a single drop, Doesn't retain any fluid in the chambers, Doesn't allow "backward" flow, Has a pump action and pressure that are strong enough to circulate blood up from your toes, but delicate enough to prevent damaging any red blood cells or capillaries
        gxt 4y ago
        I don't care how amazing the body is (it is), blood flow needs constant flow with a pulse. Put two bellows in parallel, use a linear motor to push out quickly and pull in slowly on each, and voilà mechanical heart without shear. MIT licensed, go save lives you f'ers.
        ceejayoz 4y ago
        People with a LVAD don't have a pulse, actually; it's not required. https://en.wikipedia.org/wiki/Ventricular_assist_device https://en.wikipedia.org/wiki/Ventricular_assist_device
        tibbydudeza 4y ago
        In a suitcase ???.
jcims 4y ago
It is and they do: https://en.wikipedia.org/wiki/Extracorporeal_membrane_oxygenation https://en.wikipedia.org/wiki/Extracorporeal_membrane_oxygen...
deleted 4y ago
[deleted]
ephextom 4y ago
I'm not advocating it, but intravenous ozone is a treatment offered by some alternative medical practitioners, as is rectal ozone.
- hibernator149 4y ago
  After some research, it seems like ozone is a last resort treatment in non-evidence-based medicine when vitamins and magical crystals can not cure the cancer or HIV. At least, that is what the first page of Google results tells me. So I would also not advocate it.
- LargoLasskhyfv 4y ago
  Could be used for anal bleaching as well, I guess.
azalemeth 4y ago
Not a dumb question. What you've just described is an ECMO machine ("extracorporeal membrane oxygenation", related to the surgical machines oft known as a heart-and-lung machine). The act of putting the patient on it is called putting them "on bypass" and involves cutting through some of the most major blood vessels in the body, administration of large doses of heparin as a blood thinner, and a team of about ten to twenty people to ensure that they don't die. It's a major operation. After a while the mechanical stress of the pump causes blood cells to be sheared and lyse, causing haemolysis, which would otherwise be fatal if not replaced.
- darkerside 4y ago
  Is the heart that much better of a pump than the ECMO? I didn't realize there was mechanical stress on the blood itself from the ECMO machine.
  - azalemeth 4y ago
    "Yes", is the short answer. Every ECMO machine I've ever seen uses a [1] peristaltic pump and, despite the use of tubes coated with anticoagulants and with various proprietary bits of chemistry [2] to reduce the size of the inviscid layer and hence shear stresses, the maximum length of time you can spend on them is limited. It's always a downhill battle and typically a "metric shitton" of heparin is infused in order to reduce the risk of thrombus, despite the hemorrhagic risk [3]. All of these things are fine balancing acts but you do not want to be on ECMO for a long time. Similar technologies, such as cardiac LVADs are only licensed in the UK as a bridge to transplant, for example, where a well-defined end-date already exists before putting the patient on them. [1] https://en.wikipedia.org/wiki/Peristaltic_pump https://en.wikipedia.org/wiki/Peristaltic_pump [2] https://www.terumo-europe.com/en-emea/products/tubing-set-perfusion-circuit https://www.terumo-europe.com/en-emea/products/tubing-set-pe... [3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5457945/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5457945/

dumb question -- is it not possible to just directly oxygenate blood? like what stops having a special IV that takes blood out, oxygenates it, and puts it back in?

deleted 4y ago

[deleted]

ceejayoz 4y ago

Yes, it's entirely possible; it's called ECMO. https://en.wikipedia.org/wiki/Extracorporeal_membrane_oxygenation https://en.wikipedia.org/wiki/Extracorporeal_membrane_oxygen... It's very risky and requires a nurse at the bedside 24/7, so it's a last-ditch sort of intervention.

buryat 4y ago
why is it risky?
- PeterisP 4y ago
  You need to treat lots of blood continuously, so you have to cut a bypass into the largest, irreplaceable blood vessels, unlike smaller operations like kidney dialysis where you can just "plug into" an arm. Mechanical pumping of blood is a problem as it damages blood cells. Infection is a severe risk. Any break in the operation or a temporary "plumbing issue" where the machine connects with the body can be fatal. So you need 24/7 monitoring capable of really rapid response.
- tibbydudeza 4y ago
  Red blood cells are meant to travel into capillaries so must deform but will shear easily when subjected to stress which activates clotting action - mechanical pumps still cannot replicate the pumping action of heart.
  - gxt 4y ago
    How has medical science never heard of bellows? https://en.m.wikipedia.org/wiki/Bellows https://en.m.wikipedia.org/wiki/Bellows
    - tibbydudeza 4y ago
      Heart is truely an amazing organ - don't think we will get close to a mechanical replacement. Has multiple chambers, Has chambers that pump sequentially with different pressures and volumes, Never needs to stop for additional lubrication, Never needs to be "charged", Never stops for maintenance, Is powered by oxygen delivered by the red blood cells it is pumping, Is controlled by the body's "proprietary" electro-chemical control system, Is not rejected by the body's internal bio-chemical defense mechanisms, Produces only carbon dioxide as waste, delivers that waste to red blood cells, Doesn't have a single rough or chemically reactive surface, Forms perfect in-line seals around each chamber without crushing red blood cells, Never leaks a single drop, Doesn't retain any fluid in the chambers, Doesn't allow "backward" flow, Has a pump action and pressure that are strong enough to circulate blood up from your toes, but delicate enough to prevent damaging any red blood cells or capillaries
      - gxt 4y ago
        I don't care how amazing the body is (it is), blood flow needs constant flow with a pulse. Put two bellows in parallel, use a linear motor to push out quickly and pull in slowly on each, and voilà mechanical heart without shear. MIT licensed, go save lives you f'ers.
        ceejayoz 4y ago
        People with a LVAD don't have a pulse, actually; it's not required. https://en.wikipedia.org/wiki/Ventricular_assist_device https://en.wikipedia.org/wiki/Ventricular_assist_device
        tibbydudeza 4y ago
        In a suitcase ???.

jcims 4y ago

It is and they do: https://en.wikipedia.org/wiki/Extracorporeal_membrane_oxygenation https://en.wikipedia.org/wiki/Extracorporeal_membrane_oxygen...

deleted 4y ago

[deleted]

ephextom 4y ago

I'm not advocating it, but intravenous ozone is a treatment offered by some alternative medical practitioners, as is rectal ozone.

hibernator149 4y ago
After some research, it seems like ozone is a last resort treatment in non-evidence-based medicine when vitamins and magical crystals can not cure the cancer or HIV. At least, that is what the first page of Google results tells me. So I would also not advocate it.
LargoLasskhyfv 4y ago
Could be used for anal bleaching as well, I guess.

azalemeth 4y ago

Not a dumb question. What you've just described is an ECMO machine ("extracorporeal membrane oxygenation", related to the surgical machines oft known as a heart-and-lung machine). The act of putting the patient on it is called putting them "on bypass" and involves cutting through some of the most major blood vessels in the body, administration of large doses of heparin as a blood thinner, and a team of about ten to twenty people to ensure that they don't die. It's a major operation. After a while the mechanical stress of the pump causes blood cells to be sheared and lyse, causing haemolysis, which would otherwise be fatal if not replaced.

darkerside 4y ago
Is the heart that much better of a pump than the ECMO? I didn't realize there was mechanical stress on the blood itself from the ECMO machine.
- azalemeth 4y ago
  "Yes", is the short answer. Every ECMO machine I've ever seen uses a [1] peristaltic pump and, despite the use of tubes coated with anticoagulants and with various proprietary bits of chemistry [2] to reduce the size of the inviscid layer and hence shear stresses, the maximum length of time you can spend on them is limited. It's always a downhill battle and typically a "metric shitton" of heparin is infused in order to reduce the risk of thrombus, despite the hemorrhagic risk [3]. All of these things are fine balancing acts but you do not want to be on ECMO for a long time. Similar technologies, such as cardiac LVADs are only licensed in the UK as a bridge to transplant, for example, where a well-defined end-date already exists before putting the patient on them. [1] https://en.wikipedia.org/wiki/Peristaltic_pump https://en.wikipedia.org/wiki/Peristaltic_pump [2] https://www.terumo-europe.com/en-emea/products/tubing-set-perfusion-circuit https://www.terumo-europe.com/en-emea/products/tubing-set-pe... [3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5457945/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5457945/