Diabetes - blood serum osmolarity question

[pmabraham, BSN, RN]

Good day:

Note: this is my own research into the topic, not a homework question.

As I'm reading about diabetes impact on circulation, I know increased blood sugar increases the viscosity of blood. That when you have Hyperglyemic Hyperosmolar Nonketoic syndrome, the osmolarity of blood is >= 340 with blood sugar levels >= 600 mg/dL.

Now, my question is there a calculator, research paper, etc. that goes over a formula to determine that for every x increase in blood sugar levels above normal there is a y increase in blood osmolarity?

I.e. if normal fasting blood sugar levels runs 70 to 99, and normal blood osmolarity runs 275 to 295, how much of an increase in blood sugar is required to bump up the osmolarity by 5 points, 10 points, etc?

I did try various searches; I'm not sure if I'm putting in the search criteria correctly.

Thank you.

[KatieMI, BSN, MSN, RN]

There is an (app) formula for that:

MedCalc: Serum Osmolality

[TABLE]

[TR]

[TD=align: right]Sodium (Na):[/TD]

[TD=align: left] mmol/L[/TD]

[/TR]

[TR]

[TD=align: right](optional) Potassium (K):[/TD]

[TD=align: left] mmol/L[/TD]

[/TR]

[TR]

[TD=align: right]BUN:[/TD]

[TD=align: left] mg/dl[/TD]

[/TR]

[TR]

[TD=align: right]Glucose:[/TD]

[TD=align: left] mg/dl[/TD]

[/TR]

[TR]

[TD=colspan: 2, align: center][/TD]

[/TR]

[TR=bgcolor: #cccccc]

[TH=align: right]Serum Osmolality =[/TH]

[TD=align: left] mOsm/kg[/TD]

[/TR]

[TR=bgcolor: #cccccc]

[TD=align: right]Normal Range =[/TD]

[TD=align: left]285 - 295 mOsm/kg[/TD]

[/TR]

[/TABLE]

Serum Osmolality = (2 x (Na + K)) + (BUN / 2.8) + (glucose / 18)

The relationship will be non-linear and depending on renal function and hydration status.

[pmabraham, BSN, RN]

Thank you so much!