sodium confusion

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jok200

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doing some practice questions... patients sodium is 130, but the corrected sodium is 162 because of the severe hyperglycemia, patient is being treated as if he has hyponatremia becuase the serum measurment was 120??? confused, wouldn't it be hypernatremia because his corrected sodium is 162??


thans-
 
jok200 said:
doing some practice questions... patients sodium is 130, but the corrected sodium is 162 because of the severe hyperglycemia, patient is being treated as if he has hyponatremia becuase the serum measurment was 120??? confused, wouldn't it be hypernatremia because his corrected sodium is 162??


thans-
Click to expand...

Does it involve calculating the anion gap in DKA? In that case, you use the uncorrected Na measurement, not the correct value.
 
patient with polyuria, polydipsia and altered status, physical exam = poorly responsive, poor skin turgor, bp drop 100/84 --> 80/62 on sitting with pulse increase from 92 -128. Lab: glucose 2100, sodium 130, BUN 40., osmolality - 395 (measured). when i correct his sodium is 162?? don't understand, i know that the 130 is reflective of extracellular sodium but i don' t understand how the sodium is 162 ? the books states that the 162 is what would be expected if the glucose was corrected to 100, does that mean corrected to 100 acutely or overtime?? I understand the concept of correcting the glucose and giving 1/2 normal saline now.
 
jok200 said:
doing some practice questions... patients sodium is 130, but the corrected sodium is 162 because of the severe hyperglycemia, patient is being treated as if he has hyponatremia becuase the serum measurment was 120??? confused, wouldn't it be hypernatremia because his corrected sodium is 162??


thans-
Click to expand...

Sodium went from 130 to 162?
You corrected that WAAAY too quickly.
You just gave your patient Central Pontine Myelinosis.
 
Deferoxamine said:
Sodium went from 130 to 162?
You corrected that WAAAY too quickly.
You just gave your patient Central Pontine Myelinosis.
Click to expand...

No, he means the correction formula for sodium given pseudohyponatremia 2/2 hyperglycemia.
 
jok200 said:
patient with polyuria, polydipsia and altered status, physical exam = poorly responsive, poor skin turgor, bp drop 100/84 --> 80/62 on sitting with pulse increase from 92 -128. Lab: glucose 2100, sodium 130, BUN 40., osmolality - 395 (measured). when i correct his sodium is 162?? don't understand, i know that the 130 is reflective of extracellular sodium but i don' t understand how the sodium is 162 ? the books states that the 162 is what would be expected if the glucose was corrected to 100, does that mean corrected to 100 acutely or overtime?? I understand the concept of correcting the glucose and giving 1/2 normal saline now.
Click to expand...

I'm not sure I understand your question 100%, but the idea here is that due to the increased osmolarity of serum caused by hyperglycemia, there is movement of water out of cells, which ends up diluting your serum electrolytes. The "pseudo" part of pseudohyponatremia just signifies the fact that there is no actual sodium deficit in the body, as the low reading is actually due to dilution. The formula to calculate the corrected sodium just tells you what the sodium would be if there was no movement of intracellular water. So, the question stem here actually shows a patient with hypernatremia that also has overlying hyperglycemia (likely HHNS). What is the question actually asking you?
 
yes bronx43 that is what i was thinking so this is a hyponatremic hypertonicity so i would be using a hypotonic solution like 1/2 NS to dilute the hypertonicity which would help the volume depletion problem with free water and dilute some of the hyperglycemia to slow the movement of water out of cells. the true treatment would be to correct the hyperglycemia. it states that this is a special situation of hyponatremia with hypertonicity and the only time you would use hypotonic fluids for hyponatremia. Also I don't think this is pseudohyponatremia because for that to be true the osmolality would have to be normal as well as the tonicity, both of which are elevated. You are correct in the sense that this is a dilutional hyponatremia but it is compounded with hypernatremia and hypertonicity because of the effective osmole accumulation of glucose. I was very confused when i calculated the sodium because it was 162. It asks three questions:

1-what is the cause of the hyponatremia?
2-what is the serum sodium once it has been corrected for the elevated glucose?
3-what fluid would you give?

thanks again guys-
 
jok200 said:
yes bronx43 that is what i was thinking so this is a hyponatremic hypertonicity so i would be using a hypotonic solution like 1/2 NS to dilute the hypertonicity which would help the volume depletion problem with free water and dilute some of the hyperglycemia to slow the movement of water out of cells. the true treatment would be to correct the hyperglycemia. it states that this is a special situation of hyponatremia with hypertonicity and the only time you would use hypotonic fluids for hyponatremia. Also I don't think this is pseudohyponatremia because for that to be true the osmolality would have to be normal as well as the tonicity, both of which are elevated. You are correct in the sense that this is a dilutional hyponatremia but it is compounded with hypernatremia and hypertonicity because of the effective osmole accumulation of glucose. I was very confused when i calculated the sodium because it was 162. It asks three questions:

1-what is the cause of the hyponatremia?
2-what is the serum sodium once it has been corrected for the elevated glucose?
3-what fluid would you give?

thanks again guys-
Click to expand...


you guys are making me sad...

for every 100 over 2100, you add 1.6 to the serum sodium total to get the 'actual' sodium. so 2000 X 1.6 is 32. so the 'actual' sodium in this HYPERosmolar patient is 162 then.

the cause is the glucosuria. the patient is peeing like mad and drawing water with it.

the patient is dry. you need to give insulin + D5NS.
 
I understand your confusion.....u probably wondering if you shd correct the glycemia or the natremia (corrected natremia=162). However I think it isnt a big deal becos for the fluid for both is D5W anyway. SO in an exams there is no reason to be confused...answer to your 3rd question is D5W. However I would treat it with the glucose in mind-D5W + insulin as suggested above
 
jok200 said:
yes bronx43 that is what i was thinking so this is a hyponatremic hypertonicity so i would be using a hypotonic solution like 1/2 NS to dilute the hypertonicity which would help the volume depletion problem with free water and dilute some of the hyperglycemia to slow the movement of water out of cells. the true treatment would be to correct the hyperglycemia. it states that this is a special situation of hyponatremia with hypertonicity and the only time you would use hypotonic fluids for hyponatremia. Also I don't think this is pseudohyponatremia because for that to be true the osmolality would have to be normal as well as the tonicity, both of which are elevated. You are correct in the sense that this is a dilutional hyponatremia but it is compounded with hypernatremia and hypertonicity because of the effective osmole accumulation of glucose. I was very confused when i calculated the sodium because it was 162. It asks three questions:

1-what is the cause of the hyponatremia?
2-what is the serum sodium once it has been corrected for the elevated glucose?
3-what fluid would you give?

thanks again guys-
Click to expand...

The cause of the hyponatremia is dilutional from movement of intracellular water, as we can see that the actual serum sodium is high, due to increased loss of free water during polyuria.

Given the fact that this patient is severely hyperosmolar, I would start him/her off with 1/2NS and insulin. You won't even have to add in dextrose until the glucose level is below 250-300ish.

This case seems like a HHNS due to the severity of the hyperglycemia, but we don't really know for sure unless we get the acid/base status and ketones. Remember that in HHNS, fluid deficit is the main problem, as the patient will be dehydrated 8-10 L. In DKA, the primary problem is acidosis. The initial step is both is fluids.
 
Give NS initially, no insulin needs to be administered initially. The osmolality will drop faster than you want initially with just volume resuscitation with NS. Adding insulin up front just increases the initial (too rapid) drop in osmolality.
 
You medicine guys make this way too complicated. Fluid + insulin= all better. NS, half NS, Free water, LR, D5W? Who cares? Fluid + Insulin = all better. Add a little sugar abound 250.
 
danzman said:
You medicine guys make this way too complicated. Fluid + insulin= all better. NS, half NS, Free water, LR, D5W? Who cares? Fluid + Insulin = all better. Add a little sugar abound 250.
Click to expand...

Orthopedics?
 
danzman said:
You medicine guys make this way too complicated. Fluid + insulin= all better. NS, half NS, Free water, LR, D5W? Who cares? Fluid + Insulin = all better. Add a little sugar abound 250.
Click to expand...

Yes these guys are dorks, BUT it does matter.

This patient NEEDs resuscitation first as an ER guy, I'm surprised you don/t understand this. When was the last time you resuscitated someone with D5W? Then ask yourself WHY you've never resuscitated someone with D5W.

Now to the group . . . can you animals please tell me what the pathophysiology is here . . . :smack:

You DUMP NS into this kind of patient until you've got at least 5 liters in them. Since I'm not sure if we're dealing with DKA or HHNS, I'd need more labs . . .

Plus can anyone PLEASE tell me the mEq of sodium in NS?? You're still diluting 162 people!

But the problem here is NOT the sodium. Priorities!! You fix what will kill this guys first, then you fix the underlying problem that tried to kill him and you let the sodium sort itself out (or, sometimes a sodium disturbance will manifest itself after your corrected everything else - then you tackle the sodium).
 
okay, makes more sense to me now. If I give him 1L of NS how do I know how much water is actually getting in, I understand the concept of filling the vascular space and giving him fluids because he is so hypovolemic but how can i calculate how much water from NS will get into the vasculature?
Also why do I switch to D51/2 NS around glucose of 250-300, seems that if he is still hyperglycemic why would I give dextrose, is it to prevent ketosis by administering calories??
 
Last edited:
jok200 said:
okay, makes more sense to me now. why would you give D5 instead of 1/2NS especially when he is already hyperglycemic? Also if I give him 1L of NS how do I know how much water is actually getting in?
Also why do I switch to D51/2 NS around glucose of 250-300, seems that if he is still hyperglycemic why would I give dextrose??
Click to expand...

Are you a pre-med?
 
jdh71 said:
Yes these guys are dorks, BUT it does matter.

This patient NEEDs resuscitation first as an ER guy, I'm surprised you don/t understand this. When was the last time you resuscitated someone with D5W? Then ask yourself WHY you've never resuscitated someone with D5W.

Now to the group . . . can you animals please tell me what the pathophysiology is here . . . :smack:

You DUMP NS into this kind of patient until you've got at least 5 liters in them. Since I'm not sure if we're dealing with DKA or HHNS, I'd need more labs . . .

Plus can anyone PLEASE tell me the mEq of sodium in NS?? You're still diluting 162 people!

But the problem here is NOT the sodium. Priorities!! You fix what will kill this guys first, then you fix the underlying problem that tried to kill him and you let the sodium sort itself out (or, sometimes a sodium disturbance will manifest itself after your corrected everything else - then you tackle the sodium).
Click to expand...

No, I understand quite well why you don't use d5w. That was my point. You and I are saying the same thing. Waxing philosophically about sodium levels is missing the forest for the trees.
 
no im not a premed, but judging by the confusion about fluids with this post alone it seems that some of the residents and attendings need a refresher course. Why is their always a doosh bag that comes along and post a condescending response to someone asking a question???
 
jok200 said:
no im not a premed, but judging by the confusion about fluids with this post alone it seems that some of the residents and attendings need a refresher course. Why is their always a doosh bag that comes along and post a condescending response to someone asking a question???
Click to expand...

Because you continually post M1 level questions here. I'm just trying to figure out your angle.
 
If its M1 why are so many people having trouble understanding it?? jdh71 is the only person that has actually answered it correctly from the sources I have read.... I haven't heard you comment on it yet, as a matter of fact do you even understand how fluids work. I bet you don't, I bet you think you do and still get confused on the difference between osmolality and tonicity. I am a resident but always had trouble with the fluid movement between compartment and I don't think this is easy or M1 in any way what so ever, especially when so many people seem confused on what is going on. Like for instance using hypotonic solutions to replace fluid deficit. Or the ER resident that believes all the fluids are the same, no surprise why people are getting hypernatremic and/or developing hypercholermic acidosis on the wards.. Hmmm... why don't you comment and teach me something as opposed to being a jerk.
 
jok200 said:
okay, makes more sense to me now. If I give him 1L of NS how do I know how much water is actually getting in, I understand the concept of filling the vascular space and giving him fluids because he is so hypovolemic but how can i calculate how much water from NS will get into the vasculature?
Also why do I switch to D51/2 NS around glucose of 250-300, seems that if he is still hyperglycemic why would I give dextrose, is it to prevent ketosis by administering calories??
Click to expand...

There's a way to calculate how much free water he's getting and you should look that up 😉 . . . my point, in this case is . . . it's irrelevant. If you use NS you know the fluid will stay in the vasculature - that's why we use it for resuscitation 😀.

You switch to D5 1/2 later as you've reasoned to prevent both hypoglycemia and/or a return to ketosis as you're titrating the insulin.
 
bronx43 said:
No, he means the correction formula for sodium given pseudohyponatremia 2/2 hyperglycemia.
Click to expand...

*facepalm*

You took me literally? Seriously?
Do I REALLY need to explain this?

God, this forum has become more awkward than a fart in church.
 
:laugh:I posted the answer already and everyone ignores it. quote the EM/ortho guy instead!
 
As my Indian attending would say...

Why is no one talking about the POTASHIUM!
 
Deferoxamine said:
*facepalm*

You took me literally? Seriously?
Do I REALLY need to explain this?

God, this forum has become more awkward than a fart in church.
Click to expand...

Uh... ok, what a great joke, dude. Keep 'em coming.
 
hey surge 55, sorry dude I just saw that I posted it incorrectly, but thanks for the answer and to everyone trying to help.

-laters
 
Patient comes in w/ hyperglycemia? Here's what I've learned so far:

NS first, second, and third. Insulin 4th with bridging to D5W if necessary.
 
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