Can you help me understand the rationale for choosing this IV solution?

[fatrabbit]

I'm reading through a power point and don't get why this solution is the best for the following situation:

-pt NPO

-Na 128

-K 3.5

-glucose 130

answer: D5NS with 20 mEq KCl at 75 ml/hr

I get that you'd use NS since there's a low Na. But why include the dextrose, K, and Cl?

thanks for your help

[jamisaurus]

If the patient is NPO, what might happen to their blood sugar? Is their potassium within normal limits?

[quiltynurse56, LPN, LVN]

Are they on diuretics? Especially potassium depleting

[fatrabbit]

for our class, the normative values are:

Na 135-145

K 3.3-5

glucose 70-110

* question said nothing about diuretics

[fatrabbit]

Is this correct:

NS to replenish Na

K because when Na goes up, K goes down

Dextrose b/c NPO

Also, dumb question I know, but is that 20mEq KCl per liter? If it is per liter, why would that not kill the patient? (p.s. I'm first semester so we're just getting a general overview of electrolyte balance now instead of going in depth; this is why I'm so confused)

[fatrabbit]

Is this correct:

NS to replenish Na

K because when Na goes up, K goes down

Dextrose b/c NPO

Also, dumb question I know, but is that 20mEq KCl per liter? If it is per liter, why would that not kill the patient? (p.s. I'm first semester so we're just getting a general overview of electrolyte balance now instead of going in depth; this is why I'm so confused)

*is it because we're giving it at a slow rate so the kidneys have time to excrete enough of it? So if you gave 20mEq KCl too fast, you'd kill the patient, right?

[mrsboots87]

You're starting to get there and stuff will make more sense when you move into block two and dig deeper into disease processes.

The D5NS is due to being NPO. The glucose is only minimally high but the patient is at risk for it dropping due to no oral intake.

The potassium is 3.5, and while technically WNL it has potential to go low. When you think about the 20mEq in a 1000ml of fluid, that is a pretty low amount. It is meant for potassium maintenance for those at risk of going low or who only need minimal potassium supolementation. Most facilities want potassium above 4.0 for safety, even though 3.5 is normal. Also, with healthy kidneys, at such a slow infusion rate, if the potassium were to build up, the kidneys would excrete the excess.

For the NS, yes that is partially because of the low sodium, but a sodium at that level will likely be treated with salt tabs at minimum and a hypertonic solution is likely in addition to the maintenance fluid. Being NPO, this patient is at risk for dehydration. The NS is for maintenance hydration while the patient is NPO. D5 is hypotonic in the system by itself. By combining it with NS, it become isotonic. Don't want to starve the cells.

[amoLucia]

mrsboots - you explain it pretty well. Kudos!

[KelRN215, BSN, RN]

Is this correct:

NS to replenish Na

K because when Na goes up, K goes down

Dextrose b/c NPO

Also, dumb question I know, but is that 20mEq KCl per liter? If it is per liter, why would that not kill the patient? (p.s. I'm first semester so we're just getting a general overview of electrolyte balance now instead of going in depth; this is why I'm so confused)

Why do you think it would kill the patient?

It wouldn't kill the patient because you're not bolusing it. This is maintenance IVF. The liter is going to be administered over several hours. 20 mEq KCl/L is pretty standard in IVF, even the IVF we use in children.

Also, to better help you understand why this is the correct answer, we'd need to know what the other options were. Dextrose containing IVFs are standard, especially when the patient is NPO.

[Mavrick, BSN, RN]

Why do you think it would kill the patient?

I would like to hear the thinking on this one just to get an idea how the OP is processing. No insult to you. This is how you learn. Just giving someone an answer isn't near as helpful.

An answer suitable for the real world is "This surgeon always writes this for the post op orders"

[Mavrick, BSN, RN]

*is it because we're giving it at a slow rate so the kidneys have time to excrete enough of it? So if you gave 20mEq KCl too fast, you'd kill the patient, right?

Oops didn't read this part closely enough.

So, now that you know the 20 mEq of KCl is per liter, the fluid is running at 75 ml/hr, the pt will receive that 20 mEq over a 13 hour period.

How does potassium work to kill people? After all it is one of the drugs in the execution combination that is supposed to kill people. (Lethal injection dosage is 100 mEq)