Electrolyte Replacement

[LouisVRN, RN]

I am wondering if anyone knows of any additional scenarios where one electrolyte needs to be replaced before another. The only one I know of is replacing Magnesium before potassium. It is astounding to me how many nurses on my floor do not seem to know this. We do not, at this time, have electrolyte replacement protocols, but I've heard talk of one being initiated in the near future and was looking to do a presentation on it but wanted to make sure I didn't miss anything. Obviously I'm going to do some research beforehand, but just wondering if anyone else new of any.

[GilaRRT]

I am afraid it is not as simple as one before another. Clearly, one must consider the patient from a clinical perspective. If I have somebody with hypokalaemia and hyponatraemia, I may be inclined to consider replacing sodium if said patient is seizing from the hyponatraemia.

In addition, who says you cannot consider replacing multiple electrolytes?

[April, RN, BSN, RN]

I never knew you had to replete mag before potassium. Why is that? We often replete multiple electrolytes at the same time.

[LouisVRN, RN]

From what I was taught in school and confirmed by a physician when discussing this was another nurse at the nurses station is that a patient with a low magnesium can not absorb the potassium, therefore magnesium must be normal before potassium is infused.

[April, RN, BSN, RN]

Thanks for the info!

[HamsterRN, ADN, RN]

It's not really electrolyte replacement, but sodium bicarb can cause electrolyte shifts that can result in hypokalemia so it's always a good idea to check and replace potassium prior to giving sodium bicarb, particularly if the patient is prone to ventricular rhythms. The only time I have seen an intracardiac injection of potassium was to a patient in sustained torsades. The patient's initial potassium was around 4 but then dropped to around 2.5 following IV sodium bicarb. That, combined with a QTc of around 500 msec probably put them into torsades.