From the Guidelines
A BUN level of 18 mg/dL in a 20-month-old child is within the normal range and does not indicate uremia, as the threshold for uremia is a BUN level greater than 20 mg/dL 1. This value is at the upper limit of normal but not concerning in isolation. No medications or treatments are needed for this laboratory finding alone.
- Normal BUN values for toddlers generally range from 5-18 mg/dL
- BUN should be interpreted in the context of other laboratory values, particularly creatinine, and the child's overall clinical picture
- BUN reflects kidney function and protein metabolism, and can be influenced by hydration status, protein intake, and various medical conditions If the child has symptoms of dehydration, kidney disease, or other medical concerns, further evaluation may be warranted despite the normal value.
- Regular well-child visits should continue as scheduled to monitor overall growth and development
- If there are specific concerns about kidney function, a follow-up BUN measurement along with other renal function tests might be appropriate, but this single value alone is not a cause for alarm.
From the Research
Blood Urea Nitrogen (BUN) Levels in Children
- The BUN level of 18 in a 20-month-old child can be evaluated based on reference intervals for pediatric populations.
- According to a study published in 2009 2, the reference interval for BUN in children is 8.7-18.0 mg/L, which suggests that a BUN level of 18 is within the normal range for this age group.
Factors Affecting BUN Levels
- BUN levels can be influenced by various factors, including age, sex, and protein intake 2.
- The BUN/creatinine ratio, which is higher in children than in adults, may also be an important consideration in evaluating kidney function in pediatric patients 2.
Assessment of Kidney Function in Children
- Urinalysis is a commonly used test for screening purposes in ambulatory settings, and can provide valuable information about kidney function in children 3, 4.
- Further assessment of kidney function may involve tests such as urine protein excretion, estimated glomerular filtration rate, and kidney biopsy, depending on the individual patient's needs 3.