Triple H therapy

[Epona]

Ok. I understand this helps patient's who have had a subarachnoid hemmorhage. I understand we want to keep the vessels open...hypervolemia and hemodilution. Can you explain the hypertension part? We don't want them to vasospasm. By increasing the BP (hypertension) isn't that putting them at risk for vasospasm?? Can you please explain the hypertesnion part??

Thanks very much! Have a quiz on this Monday!! Epona

[kbkrogmann]

The patients are only kept hypertensive after the anuersym has been clipped or coiled--not before. Keeping an un-repaired anuersymal patient hypertensive will put them at risk for re-bleeding. Hypertensive post-op helps keep those vessels open. Hope that helps!

[Epona]

Oh... and how does Mannitol come into play here?? I know it decreases ICP.

Thanks again! E

[meandragonbrett]

Oh... and how does Mannitol come into play here?? I know it decreases ICP.

Thanks again! E

Mannitol is an osmotic diuretic that is typically used to manage acute elevations in ICP. It decreases extracellular volume by promoting water and Na excretion.

[labcat01, BSN, RN]

I'm not a Neuro nurse but I thought that hypertension had to do with maintaining an cerebral perfusion pressure- am I wrong? Correct me if I'm wrong :)

[bellehill, RN]

You want to keep your CPP>60, ideally >70. The hypertension in a SAH pt has more to do with perfusion of the repaired vessels. A higher blood pressure will "force" the blood through a potential vasospasm and prevent ischemia. Lately we have had SAH patients where we are not monitoring ICP at all; depends on the patient.

[angel1966]

Hi Epona,

Yes, we do the Triple H Therapy for the patients with SAH/Cerebral Aneurysm, but we need to keep them hypertensive if the Aneurysm is already protected (clipped or coiled). We increase the blood pressure to improve cerebral perfusion of the brain and to prevent ischaemia or vasospasm. The doctor usually sets a BP or MAP parameters to maintain and we nurses, should not be hesistant to ask the doctors about parameters. And I think the Triple H therapy plays a very important role in treating SAH.

[fins]

Where I work we will at times keep MAPs as high as 110, assuming the aneurysm is well secured. The stroke that you're trying to prevent is an ischemic stroke due to the vasospasm clamping down the arteries. So you're willing to risk a high blood pressure for a short period to prevent that.

Think of it this way: if you're trying to push more liquid (blood) through a tube (a cerebral artery) there are three things that you can do.

You can load up the tube with more liquid - that's hypervolemia.

You can make the liquid less viscous so it slides through more easily - that's hemodilution.

And finally, you can push harder - that's hypertension.

All three have their risks. Hypervolemia risks wet lungs - up to and including pulmonary edema. Hemodilution risks depriving tissue of oxygen, if the H/H is low enough. And you're right, hypertension risks hemorrhagic stroke. It's always a trade-off on the risk/reward graph.

[aeauooo]

Oh... and how does Mannitol come into play here?? I know it decreases ICP.

Thanks again! E

In the most recent issue of the Journal of Neuroscience Nursing there is a review article comparing mannitol to hypertonic saline. One of the studies reviewed found that mannitol increases MAP - that, combined with decreased ICP significantly raises CPP.

Infanti, J. L. (2008). Challenging the gold standard: should mannitol remain our first-line defense against intracranial hypertension. Journal of Neuroscience Nursing, 40(6), 362-368.

Incidentally, does anyone remember the old definition of triple H? Hint: it had to do with the caudal end of the patient.

[FLCheerChic86]

Ok I'm still pretty new to neuro nursing but this is how I conceptualize "Triple H" therapy in my mind. After someone has been clipped or coiled they are at risk for going into vasospasm (we are becoming pretty conservative with this form of therapy at are hospital and are only implementing it if someone is actively in vasospasm). So if someone is in vasospasm, somewhere in there cerebral vasculature has clamped down and is not being perfused. I compare this with a a garden hose watering some plants.With a water spicket that is only slightly opened, with water just trickeling out of the hose are my plants going to get much water this way? No, they are going to die. So in order to get as much water to my plants as possible, we want to open that spicket up to have as much force as possible, pushing that water out with max force and max volume (Hypertensionand hypervolemia). Ha yeah the hemodilution part doesnt really work into this but I think that is kind of an easy one. Of course you want thinner blood as opposed to really think viscous blood if you are squeezing through something that is already clamped down.

[Beentheredonethat]

The mannitol is used to reduce cerebral edema. If the brain is swollen then it pushes in on the arteries. That reduces CBF. You are trying to increase CBF. Back to the garden hose. If you squeeze the hose you restrict the flow.