Low BUN and Creatinine....WHY??

[juniorminty]

Okay I'm doing my clinical paperwork from this week and I am stuck on one little part...my pt has acute pancreatitis. We were resting her pancreas, started NPO on NGT, moved to clear liquid then was switched to 1800 cal ADA diet Wednesday at lunch. She still wasn't eating much, complaining of nausea despite getting Zofran. Anywho, I'm looking over her labs (she didn't have many) and her amylase/lipase are under control, calcium/magnesium are low (normal in pancreatitis) but her BUN and creatinine are low...and I can't figure out why. There is nothing in her medication that I see that would alter those values and the only reason I can find would be malnutrition. I guess malnutrition is possible since she was NPO then clear liquid and pretty much only ate her jello on the clear liquid. I just want to make sure I am not missing anything here!

[Always_Learning, BSN, RN]

BUN (Blood Urea Nitrogen or Urea Nitrogen). This is the concentration of nitrogen(within urea) in the serum(but not in red blood cells). A waste product, derived from protein breakdown, produced in the liver and excreted by way of the kidneys. High values may mean that the kidneys are not working as well as they should. BUN is also elevated by blood loss, dehydration, high protein diets and/or strenuous exercise which may temporarily and artificially raise levels. A low BUN level may be the result of liver disease, a low protein diet, pregnancy, or drinking an extreme amount of water (dilution).

Creatinine. A waste product largely from muscle metabolism (breakdown). Concentration of creatinine in the blood depends upon the amount of muscle that you have and the ability of your kidneys to excrete creatinine. High values, especially with high BUN levels, may indicate problems with the kidneys. Low values are generally not considered significant.

from http://www.hrpca.org/index.htm

[nurseprnRN, BSN, RN]

there's a wonderful book called laboratory and diagnostic tests with nursing implications, by joyce lefever kee, that i used to assign to my students, and it's on my shelf for my own reference. it has every lab test under the sun listed alphabetically, with prep, precautions, results, rationales, and references. you will love it. it's even faster than going online, and you can sit outside on a park bench away from wifi and, like, read it.

remember that nursing implications and preps are something you'll be responsible for and they are on the nclex. great book.

[LadyinScrubs, ASN, RN]

Grn Tea, thank you for the info. You have consistently been helpful, and your advice is greatfully accepted.