Hyperdynamic circulation

Specialties CCU

Published

Specializes in CVICU.

When you have an open heart patient who is hyperdynamic with a cardiac index in the 4+ range, do you care? My CABG patient the other day had a cardiac index in the mid 4 range, SVR in the 400-500s, BP 90s systolic, good UO, good SvO2. I was thinking.. If i were to just treat the numbers I could turn on some phenylephrine and get the BP up to a more "normal" number and bring the CI down a bit to a more "normal number", but why would I do that if all signs of organ perfusion are A-OK? The only benefit I can think of is that being in such a vasodilated state and causing a hyperdynamic cardiac output like that may be unnecessary worlkload on the heart. On the flip side, I could see the benefit of not treating it and just letting things be since all my other signs point to an adequate O2 delivery. So, in a situation like I mentioned, is a high cardiac index anything to worry about?

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Specializes in Nurse Anesthesiology.

Short answer, NO. The only way I would be worried about it would be if I thought the patient was developing sepsis. But the patient you are mentioning only has that great CO because his SVR is so low. This happens a lot of times mainly because the bypass causes the body to go into a SIRS response and drops the SVR.

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Specializes in CTICU.

No, treat the patient and not the numbers - they are a guide. I would only treat if I had the patient on inotropes and I could wean some off; and watch in case pt gets too vasodilated.

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Specializes in multispecialty ICU, SICU including CV.

Agree with the above. I think one of the hardest things you have to overcome as a new ICU nurse is to learn what to treat and what not to treat. We all have the "normal" hemodynamic ranges and what drugs treat what number pounded into our head in orientation, but the reality is if fixing these numbers isn't going to do anything to improve your patient outcome, why run drugs with ugly side effects? You need to keep in mind that none of our pressors are benign. Yes, they might increase your MAP (a "number") but they also do ugly things, like decrease tissue perfusion, which from what you stated, looks beautiful right now (good SvO2, good UO). My motto always has been --- if it ain't broke, DON'T FIX IT. So, good call on your part.

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My thoughts:

-LVH may require a higher MAP for adequate coronary perfusion.

-Brisk UOP may be post-CPB phase or from mannitol (commonly used in the bypass prime).

-Your description sounds like a good snapshot in time, but you are correct about hyperdynamic myocardial stress. If the LV is banging and you seem loose post-pump, there is nothing wrong with some pharmacologic tone for the periphery.

-Another issue is that as your postop bleeds/pees/third spaces, those subtle declines in intravascular volume will manifest with profound BP dips. Adequate volume resuscitation AND drug support is wise.

-alpha agonists do affect tissue perfusion, but at high doses or if the tank is underfilled. Keep the filling pressures adequate, and low-mod doses of neo (10-50 mcg) are totally safe.

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Specializes in CVICU.

Good stuff everyone, thanks! I learned a few things here.

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Specializes in CVICU.

Was this patient on pump for his surgery? It sounds kind of like vasoplegia. http://www.anest.ufl.edu/pdfs/vasoplegia.pdf

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