ECMO pumps blood out of the body, oxygenates it and returns it to the body

Re:ECMO pumps blood out of the body, oxygenates it and retur... by Scoundreller on Thursday June 20, 2019 @06:03PM (#20237841)

But if you're going to have 1 machine, you need to build it big enough to get enough flow for recovery. And once you install that hosepipe, why bother changing.

The amount of flow needed to only sustain someone that hasn't been severely deoxygenated must be a lot less.

A smaller system might be able to initially infuse an oxygen-carrying booster (as Tour de France cyclists do) to get away with lower flow rates.

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Re:ECMO pumps blood out of the body, oxygenates it and retur... by rscho on Thursday June 20, 2019 @06:55PM (#20238231)

Actually, reducing it much while keeping the current functioning principle would be difficult.

ECMO not only oxygenates, but pumps to assist the heart. Red blood cells would not resist infusion through small cannulas at high speed. Hemolysis already is a problem with the current size femoral cannulas.

So if what you're after is flow, size is a severe limitation.

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Re:ECMO pumps blood out of the body, oxygenates it and retur... by mikecsh on Friday June 21, 2019 @03:37AM (#20240658)

Indeed - see Poiseuilles equation [https://www.openanesthesia.org/poiseuilles_law_iv_fluids/]

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Re:ECMO pumps blood out of the body, oxygenates it and retur... by rscho on Friday June 21, 2019 @04:57AM (#20240960)

Blood is non Newtonian. Poiseuilles doesn't really apply.

I'm aware that's what's taught in med school, though. At the maroscopic level, it works ok.

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Re:ECMO pumps blood out of the body, oxygenates it and retur... by robocat on Friday June 21, 2019 @05:26PM (#20246430)

Remember that the system also needs to remove CO2.

Severe hypercapnia symptoms are bad.

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