Decreased Bun And Creatine

[AMBERRN2B]

Doing my care plan, 8 month old patient in with gastroenteritis and dehydration. Patients BUN was decreased at under 4. All of the information anywhere I search states BUN would be increased during dehydration. Any ideas why it is decreased?

[EricJRN, MSN, RN]

Had this kid already been on IV fluids for a while? I wonder if they just overshot and he was too well hydrated. Low protein intake and liver problems can also cause a decrease in BUN.

[canoehead, BSN, RN]

Kid's fine, the older you get, the higher a normal BUN would be. The BUN goes up with decreasing ability of the kidneys to excrete, so a lower number is not of concern. Although the overhydration issue is interesting I've never encountered a BUN that was of clinical significance because it was too low.

Remember that kids tend to have O2 sats 98-100% normally, while healthy adults max out at 96-98% just because their systems are older- this is a similar situation. A better number may be outside usual limits, but not necessarily something you need to address in a care plan.

[AMBERRN2B]

He had been on IV fluids for 6 hours. That was my first thought, maybe they over hydrated them. I turned in my paper with that guess on there. Thanks for the help! :)