Question about cardiogenic shock

[studylol]

I'm trying to understand why uptodate has a different approach than case files.

Case files critical care says to treat cardiogenic shock with fluids if there is no pulmonary edema, then pharm (positive inotrope with vasopressor effect like norepi), then IABP (balloon). This is in order of elevating severity.

Uptodate says to treat acute decompensated heart failure with fluid restriction +- vasodilator therapy.

Is the difference that cardiogenic shock may be due to the R heart and therefore we rule it out with a fluid challenge? If so, why isn't it fluid challenge --> diuresis?

Do you guys see why i'm confused? Why are these two different!

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[Melchizedek]

From working in a Cardiac ICU here's the reasoning that I can give you (at least from clinical practice).

Acute heart failure and cardiogenic shock are two seperate states. CHF can cause the shock state.

Acute decompensation in heart failure shows signs of fluid overload, causing dyspnea, edema (not necessarily pulmonary if its not bad enough), etc.
If we don't know the patient's EF the safer bet is to fluid restrict because in 3 out of 4 situations, adding fluid will cause further decompensation (flash pulm edema). In severe/mild Left sided failure the patient's EF is too low to handle additional fluid. In severe RSF the fluid has built up systemically producing pulmonary symptoms.
Typically we'll fluid restrict and start inotrope (Dobut/Dopa/Milrinone) therapy to cover the first three cases, do an echo, right heart cath, and adjust.

Cardiogenic shock is a different state in which your organs are hypoperfusing so you want intrope support as well but mostly vasoconstriction which is why you go levo/epi/norepi. The IABP is supposed to reduce cardiac workload, facilitate recovery of the heart, and again improve perfusion.


:sidenote: Problem with Fluid challenge and then diuresis is that this could damage the kidneys, which in most CHF patients are already suffering. lasix->BUN/Cr rise -> CRRT just not a road you want to go down, but unfortunately sometimes you have to prioritize heart over kidneys. :/

 

[Levo]

:sidenote: Problem with Fluid challenge and then diuresis is that this could damage the kidneys, which in most CHF patients are already suffering. lasix->BUN/Cr rise -> CRRT just not a road you want to go down, but unfortunately sometimes you have to prioritize heart over kidneys. :/

The act of diuresis itself doesn't hurt the kidneys. It's the hypoperfusion that comes with overdiuresis. If you've given fluid and are taking it off with Lasix and the patient never becomes dehydrated, it won't damage the kidneys. There will obviously be patients with crappy creatinine who are not Lasix responsive because of acute cardiorenal syndrome, that's a different story. It's not the Lasix's fault though.

 

[Melchizedek]

The act of diuresis itself doesn't hurt the kidneys. It's the hypoperfusion that comes with overdiuresis. If you've given fluid and are taking it off with Lasix and the patient never becomes dehydrated, it won't damage the kidneys. There will obviously be patients with crappy creatinine who are not Lasix responsive because of acute cardiorenal syndrome, that's a different story. It's not the Lasix's fault though.

I'm not directly blaming the lasix, I'm aware of cardiorenal insufficiency, the issue is when physicians see edema and think "lets diurese" when the patient is most likely third-spaced and intravascularly dry, causing the pseudo-dehydration

 

[studylol]

The act of diuresis itself doesn't hurt the kidneys. It's the hypoperfusion that comes with overdiuresis. If you've given fluid and are taking it off with Lasix and the patient never becomes dehydrated, it won't damage the kidneys. There will obviously be patients with crappy creatinine who are not Lasix responsive because of acute cardiorenal syndrome, that's a different story. It's not the Lasix's fault though.

Thanks a ton for the great reply. How are the two differentiated clinically, then? Am I wrong to say that if somebody has cardiogenic shock, then they probably have LVF?

 

[Melchizedek]

Thanks a ton for the great reply. How are the two differentiated clinically, then? Am I wrong to say that if somebody has cardiogenic shock, then they probably have LVF?

Depressed EF + elevated lactate levels points to cardiogenic shock.
Depressed EF alone means CHF.
No you're not wrong but it's a squares are rectangles but not all rectangles are squares thing. Cardiogenic shock has a severe LVF and RSF as components but not all LVF aid cardiogenic shock.