Acute hyponatremia - 3% saline yes/no?

[tkim]

18 y/o F taking "Molly" before a rave. Kept mumbling about 'keep drinking water' throughout the night. Found with ALOC, GCS 9. Na 115. No seizures. 3% or hang tight?

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[alreadylernd]

Acute hyponatremia with altered level of consciousness (seizures or no seizures) is definitely an indication for 3% saline.

 

[RPedigo]

She most likely has hypotonic euvolemic hyponatremia from polydipsia, and although she does not have seizures, she does have altered mental status that is out of proportion to what is expected for MDMA ingestion (unless of course she has co-ingestions). Given that this is likely an acute ingestion from the history, the brain hasn't had time to make idiogenic osmoles to balance out the osmotic forces and therefore central pontine mylinolysis is less of a concern with correction (but of course still a serious concern). I think 3% NS to raise the sodium no more than 0.5 to 1 mEq/L/hr until her sodium is >120 mEq/L is reasonable as altered mental status even without seizures is an indication for hypertonic saline; if at that time she is more coherent, I think free water restriction to get her the rest of the way there is the way to go, again with serial sodium checks.

On the other hand, I do certainly see the merit of just free water restricting and letting her void out her extra water intake...

 

[glorfindel]

No seizures, no 3%.

Have the 3% ready to go just in case. (In case of what? Seizures!)

 

[tkim]

interesting. poll indicates most/more people would give than not. i was trained not to give unless there were seizures, and fluid restrict +/- diuretics.

 

[Rendar5]

I used to be taught as above, but the teaching's changed in the last couple years in my institute. The way we're taught to think of it now is: the patient has cerebral dysfunction due to an electrolyte imbalance. Why wait for specific tonic-clonic movements to treat her cerebral dysfunction? ****'s already hitting the fan in her brain.

It's like not pushing calcium in a hyperkalemic who's bradying down simply because there's no QRS prolongation on EKG.

Just a single push of 3% should correct it without harm. Could even do it through a peripheral since it's a single push, not like you need to set up a drip (requiring a central line).

 

[future_dr_house]

Stuart Swadron and Billy Mallon mention using sodium bicarb instead of 3% NS for ICP and hyponatremia since it is 50 cc of 8.4% NS and arrives much more quickly than having pharmacy bring it down, or in some hospital policies, having renal pre-approve the order and delaying treatment in the AMS pt or actively seizing pt. I would be worried about correcting the sodium too quickly (> 0.5 mEq / hr) though.

Has anyone done this or have some perspective on this approach? Would you just mix it with 50 cc of D5 to cut the tonicity in half or just give it as is?

 

[sanityonleave]

Stuart Swadron and Billy Mallon mention using sodium bicarb instead of 3% NS for ICP and hyponatremia since it is 50 cc of 8.4% NS and arrives much more quickly than having pharmacy bring it down, or in some hospital policies, having renal pre-approve the order and delaying treatment in the AMS pt or actively seizing pt. I would be worried about correcting the sodium too quickly (> 0.5 mEq / hr) though.

Has anyone done this or have some perspective on this approach? Would you just mix it with 50 cc of D5 to cut the tonicity in half or just give it as is?

Forgive me for the dumb question as a med student, but I thought that you only had to worry about how fast you corrected their sodium if it was a chronic problem (due to worries about CPM). Is it necessary to correct this patient's sodium slowly as well?

Again, sorry for the dumb question -- trying to learn. FWIW, we were taught that it was only appropriate to infuse 3% if the patient was seizing, and then to only raise it until above seizure threshold and stop. For an acute problem like this, diuretics / fluid restriction should bring her sodium back close to normal fairly quickly since she has good renal function and all that, correct?

 

[Rendar5]

Forgive me for the dumb question as a med student, but I thought that you only had to worry about how fast you corrected their sodium if it was a chronic problem (due to worries about CPM). Is it necessary to correct this patient's sodium slowly as well?

Again, sorry for the dumb question -- trying to learn. FWIW, we were taught that it was only appropriate to infuse 3% if the patient was seizing, and then to only raise it until above seizure threshold and stop. For an acute problem like this, diuretics / fluid restriction should bring her sodium back close to normal fairly quickly since she has good renal function and all that, correct?

The patient is already symptomatic. How long is "fairly quickly"? To me "fairly quickly" means the same thing as "a significantly longer time".

 

[xaelia]

3% saline comes from pharmacy where I work. In a seizing patient I would give NaHCO3.

In a non-seizing patient, I don't think it is mandatory to give 3% until 120meq, but certainly not incorrect. I would be averse to 3% in part due to the necessity of central access for administration and the summation of risks vs. benefits in an otherwise not-deteriorating patient.

 

[tkim]

So this was a recent case of mine. "Molly" - pure MDMA usage with assumed water intoxication. GCS initially 9 - but dropping so intubated for airway protection. Forty of lasix given in the ED. Serum/u-tox neg.

CT head looked like mild cerebral edema to my non-radiologist eyes, with obliteration of cerebral sulci, but rads says negative ghostrider.

Admit to unit, briefly discussed giving 3% saline with intensivist. Decided they wanted to wait until she got to the unit.

They gave 200cc of 3%, with slow increase in Na. Extubated HD #2, find out later that she was hippy-flipping with 'shrooms, which is neither here nor there but interesting all the same.

Repeat CT head showed more clearly-defined sulci. Hmmmm.

Still a little wacky today but definitely someone in there.

I thought about giving 8.4 bicarb as well, I guess we listen to the same podcasts - emcrit mentioned bicarb as well, but let the unit decide on correcting in the unit.

It was the most clear-cut acute hyponatremia I've seen in my short time practicing. Not the garden variety chronic hypoNa that isn't altered and no one wants to correct rapidly. Probably won't encounter another one for several years.

But then again, I'm in a college town ...

 

[jethro136]

Hypertonic saline (whether pharmacy-blessed 3% or sodium bicarb push) is clearly indicated for any profound CNS depression in hyponatremia. In this pt with a GCS of 9, definitely the right thing to do. I would probably go with bicarb myself, because an amp is going to be equivalent to roughly 120 ccs of 3% (depending on which prep of bicarb you have in your dept). I don't want to wait for her to get worse, and I'd rather not intubate so the exam is easier to follow.

Regarding correction, the goal here IS to correct her sodium quickly by a few points because she is so profoundly symptomatic. Not correct all the way, of course, but a few points. If her symptoms are truly acute then she **should** improve a fair amount with a modest increase in sodium.

 

[Tiger26]

Given that she had a GCS of 9 requiring intubation for airway protection, I'd probably give either 3% or 1.5% slowly. In addition, since she's now intubated and sedated, she may have subsequent sub-clinical seizures unless you have continuous EEG monitoring in your joint.

FWIW, I'm in the neuro ICU this month and I have three patients on hypertonic saline drips (two with 3% and one with 1.5%).

 

[Hernandez]

So this was a recent case of mine. "Molly" - pure MDMA usage with assumed water intoxication. GCS initially 9 - but dropping so intubated for airway protection. Forty of lasix given in the ED. Serum/u-tox neg.

CT head looked like mild cerebral edema to my non-radiologist eyes, with obliteration of cerebral sulci, but rads says negative ghostrider.

Admit to unit, briefly discussed giving 3% saline with intensivist. Decided they wanted to wait until she got to the unit.

They gave 200cc of 3%, with slow increase in Na. Extubated HD #2, find out later that she was hippy-flipping with 'shrooms, which is neither here nor there but interesting all the same.

Repeat CT head showed more clearly-defined sulci. Hmmmm.

Still a little wacky today but definitely someone in there.

I thought about giving 8.4 bicarb as well, I guess we listen to the same podcasts - emcrit mentioned bicarb as well, but let the unit decide on correcting in the unit.

It was the most clear-cut acute hyponatremia I've seen in my short time practicing. Not the garden variety chronic hypoNa that isn't altered and no one wants to correct rapidly. Probably won't encounter another one for several years.

But then again, I'm in a college town ...

what I don't see is what was her UOP? if she's pissing like crazy, then no, if she ain't and still have deteriorating MS, yes.

I don't give 3% outside of neuro cases much at all. unless they've are or had siezure, or getting worse, you can treat with other modalities. I've seen colleagues who were way to giddy about starting drop 3% on top of a psychogenic polyd pt who was pissing out Liters/hr, and raised the sodium from.100-130 in ~8 hours. thank god they didn't develop CPM