Student trying to understand DKA and Dehydration

[ghurricane]

Ok, I'm trying to understand the underlying pathophysiology behind why dehydration happens with DKA patients. I understand that there is an increase of glucose in the urine, and an increase in urine production, so obviously the need to urinate is substantial. Is this what is causing the bulk of the dehydration?!

Thanks

[jlr820]

Yes it is. The bloodstream is absolutely full of glucose (since it isn't entering cells and being metabolized). This glucose load makes the blood HYPERosmolar and the kidneys respond by trying to remove glucose through urination. They cannot effectively deal with the large glucose load, and that's why glucose "spills" into the urine. The process of excessive urine output secondary to the large glucose load is called osmotic diuresis, and the client loses a HUGE amount of fluid through this diuretic effect, leading to profound dehydration.

[NRSKarenRN, BSN, RN]

check out these prior posts:

question about dka - nursing for nurses

nursing interventions - nursing for nurses

clincal articles:

diabetic ketoacidosis: emedicine pediatrics: cardiac disease and

diabetic ketoacidosis: emedicine endocrinology

how do i care for a patient with diabetic ketoacidosis

dka nursing care plan

acccn's critical care nursing - google books result

[ghurricane]

Thanks so much!! Here is another oddity that makes no sense. I know there is potassium depletion due to frequent urination, but why do labs usually indicate hyperkalemia?

[Mike R, ADN, BSN, RN]

Thanks so much!! Here is another oddity that makes no sense. I know there is potassium depletion due to frequent urination, but why do labs usually indicate hyperkalemia?

Severely acidotic states bring K+ out of the cell and into the blood.

[llltapp]

And if you have someone with DKA, make SURE they have that high potassium level before you start dumping them with insulin. Because Insulin puts potassium back INTO the cell and lowers the serum K level. Keep monitoring that potassium level as you bring the sugar down, or you can make them hypOkalemic :)

[jjtkk33]

This one took me awhile too when I first started trying to understand it. Basically hydrogen ions move the potassium out of the cells which results in lab values indicating hyperkalemia, however as things are corrected with the acidosis the potassium goes back into the cells where it came from. This is why it is important to understand that they may not actually be hyperkalemic but just appear so due to the acidosis. As the acidosis is corrected and potassium returns to the cells from the blood stream the labs will show the potassium level lowering in the blood. Since potassium is excreted in the urine during osmotic diuresis and also possibly lost with emesis it is important to watch the potassium levels during treatment to make sure that they do not become hypokalemic.

This article is very helpful in understanding this http://intensivecare.hsnet.nsw.gov.au/five/doc/education_packages/nepean/nepean_guide_DKA_2007.pdf