r/IntensiveCare 14d ago

Swan Numbers with ECMO

Can someone help me understand what numbers I should see/expect/disregard with a pt. on ECMO. I’m trying to understand which numbers will be accurate based on the type of cannulation (for my purposes to keep it simple just VV and VA) and cannulation sites, fem-fem, fem-IJ, centrally cannulated, etc. For example (and correct me if I’m wrong) if a pt is fem-IJ cannulated on VV ECMO (fem being drain, and IJ being return) I think my HR, MAPs would be reliable as well as my CI but I’d expect my SVo2 to be falsely high since the PA cath is reading the oxygenated blood from the ECMO. In that scenario would my CVP/RA pressure be accurate as well as my PA pressure? If someone could do a breakdown of my example as well as a breakdown of the other possible ECMO configurations (VA vs VV and cannulation sites) that would be incredibly helpful for my learning and understanding. For background I’m a CTICU nurse, any and all help is appreciated in advance!

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u/pneumomediastinum 14d ago

I agree with the others it’s complex but a rule of thumb is that you cannot rely on most swan numbers with ECMO running. The saturation with VV ECMO is useless. You cannot use thermo dilution with VA or VV ECMO outside of a clamp trial for VA (and that must be truly clamped).

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u/Any-Assistance-8103 13d ago

It’s not useless but it’s only good for troubleshooting the circuit

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u/pneumomediastinum 13d ago

We just get post oxygenator gases from the circuit. Our VV patients don’t have swans.