Mannitol vs Hypertonic Saline in reducing Intracranial Pressure

[Kaustikos]

So,
I'm trying to get an idea for something I was taught in my EM class recently regarding reducing ICP. They discussed ventricular catheters, raising bed, etc etc but they also mentioned using mannitol as a way to reduce ICP, too. I raised an eyebrow and did some research because I'm not particularly a fan of mannitol from what I've heard and I find out that there's some controversy regarding its use.

Firstly,
Compare it to hypertonic saline.

Second, there isn't much literature supporting the idea that you should use mannitol over hypertonic saline. And some saying that it worsens patient condition.


Third, I know that mannitol is a great vehicle to deliver drugs through the BBB, but that's the only condition I could see the use of mannitol: treatment of ICP while simultaneously delivering a drug through the BBB.


So, what gives? If you're in the ER dealing with high ICP, do you actually use mannitol? Or are you going to use hypertonic saline >>>>>>>>> mannitol?

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[jdh71]

So,
I'm trying to get an idea for something I was taught in my EM class recently regarding reducing ICP. They discussed ventricular catheters, raising bed, etc etc but they also mentioned using mannitol as a way to reduce ICP, too. I raised an eyebrow and did some research because I'm not particularly a fan of mannitol from what I've heard and I find out that there's some controversy regarding its use.

Firstly,
Compare it to hypertonic saline.

Second, there isn't much literature supporting the idea that you should use mannitol over hypertonic saline. And some saying that it worsens patient condition.


Third, I know that mannitol is a great vehicle to deliver drugs through the BBB, but that's the only condition I could see the use of mannitol: treatment of ICP while simultaneously delivering a drug through the BBB.


So, what gives? If you're in the ER dealing with high ICP, do you actually use mannitol? Or are you going to use hypertonic saline >>>>>>>>> mannitol?

Bottom line? Both are effective at lowering ICP. One has not presented itself as better or worse, though properly powered trials still haven't been done. If you've got a peripheral line, then use the mannitol, if you've got central venous access then use either or. I prefer the hyperotnic saline because there is less monitoring involved.

Though the truth is that is most cases (outside of the neurosurgical side of things, where their use is more specialty specific) where you're starting to think about using it, the patient is already dead, or heading there very fast. So pick something. No one will fault you later for trying.

 

[45408]

Bottom line? Both are effective at lowering ICP. One has not presented itself as better or worse, though properly powered trials still haven't been done. If you've got a peripheral line, then use the mannitol, if you've got central venous access then use either or. I prefer the hyperotnic saline because there is less monitoring involved.

Though the truth is that is most cases (outside of the neurosurgical side of things, where their use is more specialty specific) where you're starting to think about using it, the patient is already dead, or heading there very fast. So pick something. No one will fault you later for trying.

Exactly. I did a presentation on this a few years ago, and I did a pretty thorough lit search. There's not great evidence out there, other than the fact that steroids are no longer used because they don't help (the CRASH trial).

Mannitol is safe to give peripherally. Hypertonic saline can sclerose a peripheral vein. The correct answer? Give whatever the neurosurgeon wants...

 

[adenocard]

Scott Weingart over at the EMCrit Podcast had an interesting talk about this about a month back

http://emcrit.org/podcasts/high-icp-herniation/

 

[swamprat]

One thing about manitol I am aware of is that you should not give it more than 48 hours because it will equilibriate with the brain and will do the opposite of what you want at that point.. draw water in.

 

[Laryngophed]

One thing about manitol I am aware of is that you should not give it more than 48 hours because it will equilibriate with the brain and will do the opposite of what you want at that point.. draw water in.

It also has a nasty habit of causing pulmonary edema in those with compromised cardiac function.

 

[neusu]

We use both. In the acute setting e.g. new blown pupil in the ED mannitol is referred. Trauma surgery hates mannitol because it can lower systemic blood pressure but it seems to work better and faster. Also, hypertonic saline comes in flavors from 3% to 23% NaCl and isn't always readily/immediately available (has to be made in central pharmacy).

 

[Rendar5]

I don't like either too much honestly, despite the fact that both have saved my patient's butts in the past. Mannitol has a near-immediate effect and I'm honestly not sure if it's purely just an osmotic effect since it happens so fast, but it's a temorizing measure, just like hyperventilating a patient. Great to get them to the OR, but not great if your'e treating them non-operatively. Hypertonic saline can be a drip unlike mannitol, but generally requires a central line to be placed if you want to use it n such a manner

 

[J ROD]

I would prefer hypersaline 3% over mannitol. We used it more at my hospital as well.

Also, as a note, we have premix bags in 500ml so it can be ready fast. We just made sure it was ordered over a specific time or rate.

 

[jdh71]

You can probably get away with 3% through a peripheral initiall buying you time for CVC if that what you have, but after that, the 23% is what I like best as the volumes are much, much smaller.

 

[Kaustikos]

I really appreciate all the input. As I've already mentioned to jdh, I'm just a medical student, so a lot of what I'm learning is from a sheet of paper. It's easier to get an answer to these questions by asking those who actually play the field.

I'm kinda relieved to know that this isn't a stupid question. Or if it is, I'd rather get it out of the way now instead of later.


Follow up Q; is the reason why you can use mannitol in venous thrombosis (hemorrhagic, right?) is that it only shrinks capillary endothelial cells and has no effect on cells lining the veins and won't exacerbate the issue?

 

[Kaustikos]

Disregard what I just said...

The notes said Venous Thrombosis is a hemorrhagic stroke. That can't be right.

 

[neusu]

Disregard what I just said...

The notes said Venous Thrombosis is a hemorrhagic stroke. That can't be right.

Cerebral venous thrombosis results in venous congestion and hemorrhagic conversion. Mannitol is used for its rheological effects to increase blood flow and decrease congestion.

 

[redpanda]

Also, FYI, there are guidelines (adults, peds, surgical, etc.) put out by the Brain Trauma Foundation that detail the evidence and current level recommendations for treatment of traumatic brain injury. The peds guidelines were just updated this year.

https://www.braintrauma.org/coma-guidelines/

 

[QuickChange]

Also, FYI, there are guidelines (adults, peds, surgical, etc.) put out by the Brain Trauma Foundation that detail the evidence and current level recommendations for treatment of traumatic brain injury. The peds guidelines were just updated this year.

https://www.braintrauma.org/coma-guidelines/

I am Anesthesiology and Critical Care resident. Our critical care service coverages all NSGY ICU patients. I can just say what we are taught and our practices in the unit between mannitol vs Hypertonic. Mannitol is only given within 48 hours of initial Intracranial incident. It is more effective and can be given more easily. However it gradually becomes less effective after each subsequent dose and can be detrimental if given two frequently.

So our common practice is to given mannitol prior to having any ICP monitoring. Rarely have i seen it given after 24 hours. Similar to hyperventilation, it lowers ICP, but its never used on vent or any time after surgery. We are only taught to hyperventilate pts going OR emergently where we are bagging the patient prior to surgery and at induction. We really never hyperventilate pts 6 hours after the inciting injury.

Hypertonic saline either 3% or 1.8 % percent is given continuously. Goal to keep Na between 150-160 because osmolarity, drives water in the brain, not oncotic and interstitial pressures in other body locations. This reduces brain volume (brain volume, intravasculature volume, and CSF) one of three items contributing to ICP. Important to understand that pts on Hypertonic saline may not have any issues with ICP as in NeuroICU pts they are often salt wasting and hypertonic saline is given to replace sodium and maintaining plasma serum.

The question is as simple as which is better? But rather which tx is more appropriate.

 

[jdh71]

I've also used CRRT in acute livers to keep the serum sodium ~160, even pushed past 160 to 165-170.

I cool them as well

 

[dpmd]

Also, hypertonic saline comes in flavors from 3% to 23% NaCl and isn't always readily/immediately available (has to be made in central pharmacy).

Mannitol is in the ED pyxis and hypertonic saline you have to place an order for, have said order flagged, argue with the pharmacist about the appropriateness of the med, wait for it to get mixed after persuading pharmacist that you are correct (or getting them to ask one of the clinical pharmacists who have a clue), then hope the nurse notices it has arrived. Not exactly an emergency option at many institutions (I'm guessing mine isn't the only one)

 

[danielpreciad]

Scott Weingart over at the EMCrit Podcast had an interesting talk about this about a month back

 

[joeDO2]

there was a recent article about this in NEJM talking about this you might want to check out.....maybe a few weeks ago now

 

[Siverhideo1985]

You can probably get away with 3% through a peripheral initiall buying you time for CVC if that what you have, but after that, the 23% is what I like best as the volumes are much, much smaller.

Any problems when you go to 23% for longer times? Precipitation or salting out proteins around the catheter?

 

[jdh71]

Any problems when you go to 23% for longer times? Precipitation or salting out proteins around the catheter?

Good question. And one I'm not sure about. Everyone we've busted out the 23% on in the past 4 years hasn't made it.