How to determine dehydration

[motherinlaw]

How do I determine that the patient is dehyrated by looking at the lab values. I know this shows in the BUN & creatinine levels, but I can't remember. Is the BUN elevated and the creatinine low???

[BBRANRN2013, ASN, RN]

Aren't they both elevated in dehydration?:confused:

[motherinlaw]

I'm not sure that's why I'm asking

[xtxrn, ASN, RN]

Electrolytes, urine specific gravity, CBC....chem panel....all can give indications of dehydration; do you have your lab manual/handbook?

[SweetseRN]

In dehydration BUN is elevated while creatinine remains normal. If both BUN and Creat are elevated, then you most likely have some type of renal failure.

[Anna Flaxis, BSN, RN]

In dehydration BUN is elevated while creatinine remains normal. If both BUN and Creat are elevated, then you most likely have some type of renal failure.

Creatinine can most certainly be elevated in dehydration, and both BUN and Cr can be in their normal range even with a significant amount of kidney dysfunction.

A more useful indicator is the BUN/Cr ratio.

Elevated values with a ratio of >20:1 indicate some form of prerenal cause such as dehydration. Elevated values with a ratio of =10:1 indicate an intrarenal cause.

[chulada77, ADN, BSN, MSN, APRN]

In dehydration BUN is elevated while creatinine remains normal. If both BUN and Creat are elevated, then you most likely have some type of renal failure.

I second this answer!

[BBRANRN2013, ASN, RN]

Urea

Reference range

2.0 - 8.2 mmol/L

Increased in

Prerenal factors

hypovolemia

dehydration

hemorrhage

loss of fluids (renal, gastrointestinal tract)

congestive heart failure

sepsis

drug-induced

catabolic state (eg, trauma, burns, fever)

high protein diet

[BBRANRN2013, ASN, RN]

Creatinine

Reference range

Male:60-115 μmol/L

Female:40-95 μmol/L

Increased in

Prerenal factors

hypovolemia

dehydration

hemorrhage

loss of fluids (renal, gastrointestinal tract)

congestive heart failure

sepsis

drug-induced

consumption of cooked meat

I found this stuff in my Lab stuff on my iPad. Don't know if it's correct or not!

[Chisca, RN]

Sodium level. Elevated, dehydration. Decreased, fluid overload.

And if you really want to impress your friends calculate the serum osmolality using the measured sodium, glucose, and BUN.

http://www-users.med.cornell.edu/~spon/picu/calc/osmolal.htm

[Christy1019, ASN, RN]

Sodium, BUN and Creat can definitely be elevated in dehydration, or may be completely normal. The way I remembered it was to think of those values being "concentrated" due to decreased fluid volume (blood is made up of mostly water, dehydration reduces the total volume of the circulating blood)

another assessment tool for dehydration is orthostatic vital signs, if the patient is dehydrated their blood pressure should decrease and heart rate increase when changing from flat to upright. Tachycardia at rest can also indicate dehydration/fluid volume deficit because your heart is pumping harder to try and circulate less volume throughout the body.

hope that helped..

[Isitpossible, LPN, LVN]

elevated hematocrit also indicates dehydration