Correcting low sodium too quickly

Advanced Practice Columnist / Guide · Apr 8, 2015

I'd be curious to see what the Nephrologist says. But this being not my patient where I see the whole picture, I will weigh in with random thoughts.

One of the steps in evaluating hyponatremia is to assess for other factors that artificially lower the serum sodium. Hyperglycemia (serum glucose greater than 100) can artificially lower the serum sodium so you must calculate the corrected serum sodium. Going by that link, her corrected serum sodium is 115.

There is an algorithm for hyponatremia that providers follow in terms of determining the cause. Based on what you wrote on your patient's case, nausea and vomiting (GI losses) appear to be the culprit. However, what confuses me is that the Nephrologist also gave Lasix which makes me think that the assessment is that the patient has hypervolemic hyponatremia. Typically, you don't see that in a patient with nausea and vomiting.

The other important consideration in hyponatremia is the speed of sodium correction. Maximum rate of correction should not be more than 8-10 mmol/day in a patient without neurologic compromise (as is your patient). That is probably why the Nephrologist says call if serum sodium is 125 (remember corrected serum sodium is 115).

I feel that the rate of correction was quick as well like you did but I don't know what the glucose was if it's still high. So that's why I'm curious what happened next. I would in that case stop the hypertonic saline.

Anna Flaxis, BSN, RN · Apr 8, 2015

Well I got yet another patient with a critical sodium and potassium. K was 3 and sodium 113 when she came to me from the ER. She was alert and oriented, BP at 189/102. She also had gastroperesis and had been vomiting a small amount the days before admission, but only nausea at the hospital. She was a diabetic. Her blood sugar was 318 when she got to my floor. I gave her 6 units of Humalog and she was 199 a couple of hours later.
The nephrologist had ordered her ns @ 125 and labs. I called him with the critical sodium and was told to change to 3% saline for 300 Mls and to run @50. Also told me to give Lasix with that and call if sodiums 125.

Based on the above, to me it sounds like this person had hypertonic hyponatremia r/t the high CBG. A serum osmolality of >295 would confirm this.

If she was hyponatremic for 48 hours or less (which sounds likely), then more rapid correction is safe, however, if she was asymptomatic, treatment should be aimed at correcting the underlying cause, which in this case would be the hyperglycemia.

MunoRN, RN · Apr 8, 2015

The initial corrected sodium level was a little better than it appeared, 115 corrected instead of 113 uncorrected, but that is still a significant hyponatremia and won't be fixed by just treating the BG.

While acute hyponatremia can be corrected a bit faster (

Hyponatremia shouldn't be considered comparable to other electrolyte imbalances where errors in treatment can cause serious problems but those problems are still relatively fixable. I've personally seen two patients die from correcting sodium too fast. One went into respiratory arrest on the floor, the other was found unarousable but still alive. Both had normal neuro exams prior to that. The one that survived initially appeared brain dead, although an EEG suggested locked-in-syndrome. That patient died a few weeks later as they had not wanted any life support in the case of severe neurological dysfunction.

jadelpn, LPN, EMT-B · Apr 25, 2015

Not knowing the entire picture, here's just a few random thoughts. Very interesting information regarding sodium by pp--I learned a lot from the information!!

Just to add to the above, I would question watching the patient's potassium as well. 3 is not horribly low, but enough that if you are giving Lasix it would warrant attention as well, and part of the serial labs. As well as cardiac monitoring/seizure precautions.

I would also be curious as to what the patient's BUN and Creatinine levels were. A change secondary to DM? As well as untreated HTN that has lead to some kidney malfunction. Or acute kidney failure.

Additionally, I would also wonder if the patient has sepsis, however, just a thought process--not enough information to assume that.

I am also curious if the MD will have the patient dialyzed....

Keep us updated, this is a really interesting case.

Anna Flaxis, BSN, RN · Apr 25, 2015

If the person is older and on diuretics or has other comorbidities, it's safe to assume the hyponatremia is chronic and to treat it as such. Sometimes, however, it can be assumed that it is acute, as in water intoxication in an otherwise healthy 23 year old, or DKA in a younger Type 1 diabetic, who is a repeat customer, who occasionally stops taking their insulin for a few days because they're doing meth, and so you do have baseline sodium levels on them from previous visits.

It's really important to look at the entire clinical picture. Of course, in the event of unknowns, it's always safer to err on the side of caution.

Dranger · Apr 25, 2015

Severe hyponatremia is a nephrologists nightmare. Also annoying to deal with in DKA patients because of corrected sodium

nurseprnRN, BSN, RN · Apr 25, 2015

Hyponatremia can also CAUSE N&V if there's a little cerebral edema going on from it.Of course her gastroparesis would make her nauseated, but it's always possible to have more than one thing wrong with you.

Develop slowly, fix slowly; develop rapidly, fix rapidly. Agree c Dranger about how annoying it is to get it right. Seeing Na+ seesawing from 115 to 150 and back again isn't good, either.

Chisca, RN · May 4, 2015

Rule of 6's.

The recommend correction of no faster than 6mEq/day for patients with severe chronic hyponatremia, with 6mEq in 6 hours on the first day if symptoms are severe. This has led to the rule of 6s.

6 a day makes sense for safety
6 in 6 hours for severe symptoms and stop (no more correction that first 24 hours)

Renal Fellow Network: Hyponatremia correction; rule of 6s