Hyponatremia case

[24858]

60yo male with cirrhosis, ascites, alcholism, with a sodium of 117, presents with a strangulated umbilical hernia. He has a history of hyponatremia, when you look at blood work over the past few years his sodium ranges from 115 to 130. He has no neurologic symptoms- no visual changes no confusion, no clonus. INR is normal, platelets are normal but there are numerous ecchymoses on his arms. Surgeon says he can do the case under local.
Any thoughts?

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[pd4emergence]

Does local to this surgeon mean IV ga on your part or does it really mean local?

 

[Idiopathic]

does it matter? what would you correct his Na to and how quickly? I dont think id have a problem doing the case you describe.

 

[sevoflurane]

117 is very low... but in the context of chronic hyponatremia AND strangulated hernia I would consider doing it if the surgeon told me it was an emergency and could not wait: I would document it as such and give a slow infusion of hypertonic NS to get him above 125. I would not raise the NA> than .5-1meq/hr.

117 without proper documentation may be undefensible in court.

 

[pd4emergence]

does it matter? what would you correct his Na to and how quickly? I dont think id have a problem doing the case you describe.

One of the worst things we could do to this guy is correcting his Na too fast. A local with minimal hemodynamic changes would keep us from having to give him large fluid boluses in a short time. By the way, assuming 100kg, and a target of 130 the rate for normal saline is about 195 cc's/hr for 0.5meq/hr correction rate. As long as you keep it to 400cc's/hr for the duration of the case, it doesn't really matter how you do the case from a Na standpoint. 3% saline would be a better choice for this guy over the next day or so (75cc/hr). I would probably start it at 40 or so at first just to see how quickly it changes. I would try to get him into the 120's and hopefully by then somebody else would be looking at him with regards to fluid restriction/vasopressin receptor antagonists/demeclocyline.

 

[Sergio99]

117 is very low... but in the context of chronic hyponatremia AND strangulated hernia I would consider doing it if the surgeon told me it was an emergency and could not wait: I would document it as such and give a slow infusion of hypertonic NS to get him above 125. I would not raise the NA> than .5-1meq/hr.

117 without proper documentation may be undefensible in court.

Not only it is a context of "chronic hyponatremia AND strangulated hernia," but it is also a context of asymptomatic chronic hyponatremia:

...He has a history of hyponatremia, when you look at blood work over the past few years his sodium ranges from 115 to 130. He has no neurologic symptoms- no visual changes no confusion, no clonus...

I think it would be worse to try to correct it preoperatively and cause more harm by doing so. Pontine and extrapontine myelinolysis is not a benign thing. Even though I have never seen one, I have read that 8 mMol/day is the maximum rate of correction considered acceptable in the setting of chronic hyponatremia. I would be more aggressive in an acute hyponatremia situation, but not in this case. Here, I think I would proceed cautiously with surgery, giving sodium only to the extent of preventing further hyponatremia and monitoring carefully to avoid sudden overcorrection.

 

[fakin' the funk]

Why is anyone here trying to correct his sodium?

 

[Idiopathic]

Why is anyone here trying to correct his sodium?

my point also. i understand the implications of a rapid correction as well as the implications of acute hyponatremia. neither need apply here

 

[pd4emergence]

Why is anyone here trying to correct his sodium?

I think his Na should be corrected but not preop. There is not really any question that this guy needs to get done. He is asymptomatic from his hyponatremia, do the case, limit fluids the best you can, follow his Na's closely. They are probably gonna go up during the operation due to fluid administration. Post op is what I was addressing in my previous post.

 

[sevoflurane]

So... when would you correct the [na]? 110, 105, 95, 65?

Sure he is asymptomatic now. Must we wait until he develops symptoms to treat it? I don't think so.

I see no harm in slowly correcting his sodium to 125 over many hours...

Why wait post-operatively when you can begin a slow infusion now?

The qustion is why is his Na so low? The differential is wide.

 

[pd4emergence]

So... when would you correct the [na]? 110, 105, 95, 65?

Sure he is asymptomatic now. Must we wait until he develops symptoms to treat it? I don't think so.

I see no harm in slowly correcting his sodium to 125 over many hours...

Why wait post-operatively when you can begin a slow infusion now?

The qustion is why is his Na so low? The differential is wide.

His Na is gonna go up intraop with the fluids you end up having to give him. I think starting 3% ns preop may put you over the ideal correction rate and cause problems. If you look at the replacement formula 800cc of NS is going to correct him about .5 meq/hr (just guessing his wt is 100kg). He is gonna get that in the OR. Adding a 3% infusion to that doesn't leave much room for error. If it really was gonna be a quick true local case, he may not need more than that 800ccs. My guess is that this was not a quick local type of case. I agree that the differential is wide but this guy has hepatic insuffiency with ascities and with a history of chronic hyponatremia, that is the most likely culprit. Either that or he has been on a weeklong bender, drinking nothing but Milwaukee's best. If he has been throwing up for 7 days because of his strangulated hernia there may be a different story here but my guess is that it is his cirrhosis.

 

[pgg]

I would not delay the case to correct (or begin correcting) this patient's Na. Chronic, documented asymptomatic hyponatremia doesn't put him at risk for sudden brainstem herniation; rapid correction is unnecessary and likely more risky.

As I understand it, central pontine myelinolysis is a far greater risk with rapid correction of chronic hyponatremia than it is when correcting acute hyponatremia. This is the last patient who should get abruptly corrected.

3% saline would be a better choice for this guy over the next day or so (75cc/hr).

Does 3% vs NS matter? 3% is definitely indicated for initial rapid correction of 4-6 mEq/L in a symptomatic patient, but I don't see any advantage when it comes to the gradual correction to more normal levels.

Also, he doesn't need a central line for his surgery. While you don't HAVE to give 3% through a central line, nurse/floor protocols everywhere I've been would put a halt to 3% through a peripheral IV. Just using NS avoids the central line issue altogether.

So... when would you correct the [na]? 110, 105, 95, 65?

Sure he is asymptomatic now. Must we wait until he develops symptoms to treat it? I don't think so.

I would begin an emergency case in any asymptomatic chronically hyponatremic patient regardless of level, of course with a mind toward probable root causes, careful fluid management, and slow correction.

What's the risk we're afraid of here? Herniation or seizures - not going to happen, he's been <120 forever. In a chronic, asymptomatic patient, I don't see an advantage to preop correction that outweighs whatever makes the case an emergency.

I see no harm in slowly correcting his sodium to 125 over many hours...

Why wait post-operatively when you can begin a slow infusion now?

The qustion is why is his Na so low? The differential is wide.

I agree with all of this.

 

[pd4emergence]

I would not delay the case to correct (or begin correcting) this patient's Na. Chronic, documented asymptomatic hyponatremia doesn't put him at risk for sudden brainstem herniation; rapid correction is unnecessary and likely more risky.

As I understand it, central pontine myelinolysis is a far greater risk with rapid correction of chronic hyponatremia than it is when correcting acute hyponatremia. This is the last patient who should get abruptly corrected.




Does 3% vs NS matter? 3% is definitely indicated for initial rapid correction of 4-6 mEq/L in a symptomatic patient, but I don't see any advantage when it comes to the gradual correction to more normal levels.

Also, he doesn't need a central line for his surgery. While you don't HAVE to give 3% through a central line, nurse/floor protocols everywhere I've been would put a halt to 3% through a peripheral IV. Just using NS avoids the central line issue altogether.




I would begin an emergency case in any asymptomatic chronically hyponatremic patient regardless of level, of course with a mind toward probable root causes, careful fluid management, and slow correction.

What's the risk we're afraid of here? Herniation or seizures - not going to happen, he's been <120 forever. In a chronic, asymptomatic patient, I don't see an advantage to preop correction that outweighs whatever makes the case an emergency.




I agree with all of this.

I think in most patients .9% ns would be preferable. Problem is for this patient, it's gonna take a pretty high infusion rate to correct him when what he probably needs is fluid restriction (I am betting this hyponatremia is in the euvolemic/hypervolemic arena in the face of hepatic insuffiency). Post op, if I was continuing to manage him and his hyponatremia turned out to be truly due to his cirrhosis, I think getting him into the 120's with some extra Na is reasonable. To me it doesn't make sense to pound him with a ton of normal saline. His calculated rate for NS would be 195cc/h over 16 hrs to get him to 125 if he weighed 100kgs. That's more than 3 liters. Just seems like alot to me in a patient who probably already has increased total body water.

As far as the case goes, I agree there is no reason to postpone this case for sodium correction.