Diabetes mellitus question, why electrolyte composition change?

[scilearner]

Hello everyone,

 

A 20 year old insulin dependent diabetic female was admitted to casuality in a semiconscious state. Her plasma values are as follows. a) on admission, b)eight hour after therapy with insulin,saline etc.

 

Na+ a) 127, b)134, normal- 132-144 mmol/l

K+ a) 7.0, b)3.1, normal- 3.2-4.8 mmol/l

Urea a) 10.1, b)6.0, normal- 3.0-8.0 mmol/l

Creatinine a) 0.18, b)0.07, normal- 0.06-0.12 mmol/l

Phosphate a) 1.85, b)0.30, normal- 0.6-1.3 mmol/l

 

This is what I think why these values have changed. Please add and correct me if I'm wrong.

 

Na+ = Sodium has decreased initially. Due to osmotic diuresis. Large amount of sodium is lost in urine. I'm also thinking lack of insulin depresses the ativity of sodium potassium atpase pump, so more sodium enters cells not sure about this.

K+ = Sodium potassium pump depression, creating efflux of Potassium. Also due to osmotic diuresis, water is lost so this increases plasma K+ concentration. Also after insulin treatment K+ moves into cells due to increased activity of sodium pottasium pump.

Urea, creatinine, phosphte= Are they increased due to water loss or is diabetic nephropahy involved in this. If Diabetic nephropathy is involved how can they become normal after treatment.

 

Your help is much appreciated. Thanks

[ewmon]

From my very basic knowledge, and disregarding the diabetes due to my lack of knowledge of that condition:

 

The creatinine concentration is a key indicator of hydration, and it is inversely proportional to the water content of the urine: less water → higher conc, more water → lower conc. Muscles produce creatinine, and its average concentration is roughly proportional to the patient's muscle mass. It normally does not vary whether the patient exercises or not; however, the concentration will increase due to muscle and tissue trauma.

 

The elevated values for most of the concentrations (specifically creatinine) at admission looks like she was dehydrated.

 

The drop in creatinine (to 39% of its original value) tells me that the second sample was taken after rehydration, and that the other concentrations that showed significant drops (K+ 44%, Urea 59%, and Phos 16%) of their initial values did so due to the rehydration. The Na+ concentration didn't drop due to the patient receiving saline and the body highly regulates sodium (which would also be why its initial value was so close to its normal range).

 

I cannot talk to how diabetes affects these results.

Edited January 29, 2011 by ewmon