IV fluid question

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Ok, I just took my first test on F and E and this is not my first attempt at Med Surg II. I studied my butt off for this test and after taking it I do not feel as though I did any better on it than I did the first time I took the course (last spring)

Any who, I am stumped on the first question on the test which read:

Your patient is admitted to the hospital, upon review of her lab values you find Cl- 88 Na+ 160 K+ 4. Which of the following IV solutions would you administer?

A Lactated Ringers

B D5W

C D10W

D .45NS with Potassium

I do not know the answer to this question, or why I should know the answer, as EVERYTHING I have been assigned to read has only what to do for high or low sodium or high or low chloride, and how they go together and mimic each other, and treating one will treat the other....So how am I supposed to know which one of these to give? Obviously, the potassium is normal so I'm not giving D. I would think that giving D10W would completely flush out the sodium taking chloride with it, but I dont know about A or B. I chose A because I thought D5W would also give free water and flush out sodium with chloride, but I guess A is wrong too since it contains sodium. What is the answer. And Why?? I have been back through all of my material and still can not come up with the answer. Please, please! help me! :uhoh3:

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Specializes in Med Surg - Renal.

I loaned my FnE made EZ to a nursing student. A quick search on hypernatremia indicates D5W is the answer. D10 might bring the sodium level down too fast.

In cases of hypovolemia, volume is replaced with LR or NS before giving the D5W, but your question doesn't mention that.

WRT the low chloride, in cases of acid base imbalances, chloride moves opposite of bicarb, which could account for the sodium and chloride not moving together in your example.

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Specializes in being a Credible Source.

I chose D5W. Here was my thinking:

The patient is hypernatremic and normokalemic.

LR: It has K which the patient doesn't need (but can tolerate in LR concentration) but still has lots of Na (though less than NS). Pass on LR.

1/2NS c K: The K-rider will drive the K value up and the 154 mEq/L of Na is still working against the patient's underlying condition. They need to lose Na, not gain it.

D5W vs. D10W: The dextrose solution quickly gets metabolized leaving hypotonic solutions which will bring the Na concentration down. The 10% solution will end up even more hypotonic and could lead to an overshoot. Also, the more concentrated the sugar water, the harder it is on the veins so go with the 5% solution.

D5 for me.

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I forgot to add that the patient was npo with ng tube...so d5w to reduce the sodium..so I just don't worry about the low chloride?

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There's so much that can be read into the question....hypernatremia combined with hypochloremia...the opposite of what you would with expect sodium and chloride which usually parallel each other...is usually indicative of an acid-base imbalance and most likely metabolic alkalosis as a result of gastric suctioning.

But, if you just look at the information given and the answers given, you can knock out three and come up with the most likely correct answer. You have a normal K level, so you can eliminate LR and .45 NS+K since they both contain K and you don't want to increase the K level. D10W is a hypertonic solution...which will move fluid from the cells to the ECF. You already have a high Na level, which causes the fluid in cells to deplete and the last thing you want is to remove even more fluid from the cells. The biggest concern with hypernatremia is brain cell dehydration. That leaves you with D5W, which is isotonic/hypotonic and can be used to rehydrate the cells.

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On second thought, the metab alk may be due to excessive vomiting due to the patient being npo and ng tube in place. Yes, I woke up this morning thinking about this question...:) Just an FYI for anyone else reading this.

In any event, I've learned with nursing test questions, it's best to go with the information given and not to read too much into it. But the low chloride and high sodium was an interesting question. Has your instructor given you the correct answer and why?

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...But, if you just look at the information given and the answers given, you can knock out three and come up with the most likely correct answer. You have a normal K level, so you can eliminate LR and .45 NS+K since they both contain K and you don't want to increase the K level. D10W is a hypertonic solution...which will move fluid from the cells to the ECF. You already have a high Na level, which causes the fluid in cells to deplete and the last thing you want is to remove even more fluid from the cells. The biggest concern with hypernatremia is brain cell dehydration. That leaves you with D5W, which is isotonic/hypotonic and can be used to rehydrate the cells.

Regarding this part above: D10W is technically hypertonic, but as a previous poster stated, it becomes metabolized very quickly and then become hypotonic. Same as with D5W, starts out isotonic, but then metabolizes and becomes hypotonic. You have to be careful with D10W because you can overload the person too quickly and then you have a whole set of new problems on your hands. So D5W is your best bet.

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Yes that does make more sense...thank you! Always learning. :)

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You're welcome. Your post was on the right track, and it shows you're thinking, which is a good thing.

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Thank you for your replies. I do not get my test back until Monday so I will let you all know then. I am sure it is D5W but I did read into the question only because the questions they give us are all critical thinking. I would not assume a patient has something going on...but...if I can conclude it with the information given, well then I had better be able to do it! I am frustrated because this is my second time in the course which has a 22% pass rate and I really just want to pass this time. Last spring I was only 1 of 40 who made it to the final exam out of 164 to start. Only 15 of those passed the course. I am just trying to figure out where I went wrong and not repeat the same mistakes this time around! Thanks again:yeah:

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