Jacked Up Sodium

[OutlawNurse86]

I've only been a nurse for a year, so maybe some of y'all with more experience can help me out here.

I had a patient this weekend with a jacked up sodium level, and I can't figure out what caused it.

This elderly lady was at a party and fell face flat. They rushed her to the ED, did CT scans, X-rays, all that good stuff. She fine (in pain, but no fractures, etc). They could find no reason to admit her, so as they were discharging her, she became dizzy and dang near fainted. Just then they got the results back from her BMP and said, "Oh looky here, her sodium is 120, lets go ahead and admit her.". So they give her a 500cc NS bolus and sent her up to my med-surg floor with an IV of NS going at 100ml/hr.

Her BMP was rechecked in the AM, roughly 6 hours later..... Her Sodium was 119. My only response was "What the ----?, How the heck can that happen?". (Strangely enough, with the low sodium, she was still alert and oriented, no confusion at all).

I called her doc and got the following orders: Recheck BMP in 8 hrs, place on 900cc/24hrs fluid restriction, stop the NS and start 3% NS in 100ml bags at 33ml/hr.

Over the next day and a half her sodium came up to 128, the 3% NS was decreased to 15ml/hr. Then it was 131. Her IV was hep locked and she was kept on the fluid restriction. The last day I worked it was 132. The doc didn't want it to go up too fast. I left work to start my days off so I don't know what ever happened to her.

My question is....How the heck could her sodium get lower after a bolus and being on regular fluids for 6-7 hours? At first I thought the lab screwed up, especially since she wasn't confused (She was 85). This has been naggin me all weekend.

[cookienay]

I am soooo not smart enough to be reading this thread.

:)

[Whispera, MSN, RN]

Avocado's number = the number of avocados on a tree?

Thank you Gila, you really helped me understand the basics behind what was going on with this patient. I knew NS wouldn't have much impact in changing Na level, but you got it into the details for me!

[OutlawNurse86, BSN, RN]

Thanks y'all. My old instructor would kill me if she knew I forgot that. Amazing what you can forget in a year *smacks forehead*.

This was a remarkably healthy 85 yr old. Not a CHFer, no kidney probs, she lived in independent living at a local retirement community. I don't even think her doc knew what caused the sodium to drop.

As far as the people who are shocked that she was about to be released..... My place of employment (which has been very good to me, I love working here) does odd things. That's all I can say. Personally, even without knowing her sodium was that low, I would have at least admitted her for 23 hour obs, but oh well.....

[blondy2061h, MSN, RN]

I've always seen fluid restriction used to try and raise sodium (plus 3% sodium or PO sodium). It seems odd to me that they'd give her so much fluid (the 500cc bolus + 100cc/hr). Can anyone explain the rational to me of giving a fluid bolus (even if that does have some sodium in it?).

[GilaRRT]

I've always seen fluid restriction used to try and raise sodium (plus 3% sodium or PO sodium). It seems odd to me that they'd give her so much fluid (the 500cc bolus + 100cc/hr). Can anyone explain the rational to me of giving a fluid bolus (even if that does have some sodium in it?).

Volume depletion with concomittant hyponatremia. Hyponatremia is associated with several types of pathologies, not just the the hypervolemic dilutional hyponatremia we often associate as the definitive cause of this particular electrolyte imbalance.

[Lab Scientist]

Just a comment from a Lab Scientist point of view:

The value may not have dropped, but could have been the same or actually risen.

I know this sounds like a crazy statement, but if you understand how our instruments work and basic statistics, you can reasonably conclude that 120 and 119 are essentially the same number. You can run a specimen 20 or 30 times on an instrument and get 20 or 30 similar or slightly different values. There is an acceptable range (within Gaussian distribution or 1-2 standard deviations from the mean of a set of values) for any assay.

For example: if that 120 had been repeated, it may have been 119 or 122 or 121, etc.

You can't conclude that the patient's condition is worsening based on two lab values so close together within the assay's range of acceptability.

In our lab, a sodium (control value) of 123 can acceptably be reported as 120, 121, 122, 123, 124, 125 or 126 since all these values are within 2 standard deviations of the mean=123.

Hope this helps and doesn't just muddy the waters.

[turnforthenurse, MSN, NP]

With hypernatremia, think dehydration. Lots of solute, but not a lot of circulating volume.

With hyponatremia, think too much fluid. Normal saline, as previous posters have mentioned, doesn't contain a whole lot sodium. With that bolus, you're expecting the sodium level to become even lower - and it did. Typically with hyponatremia, you put the patient on a strict fluid restriction. The doc may order some hypertonic saline, which should be given very, very slowly. I will still never forget the Grey's Anatomy episode where Dr. Karev told the RN to give hypertonic saline at 500cc/hr and his patient died.

Hyponatremia in general needs to be collected very slowly because corrected too rapidly could cause central pontine myelinolysis which is very, very bad. Basically what happened to Dr. Karev's patient!