BUN/Creatinine Ratio

The BUN/Creatinine Ratio is a clinical calculator used in the field of nephrology and internal medicine. BUN stands for Blood Urea Nitrogen, a waste product generated in the liver and excreted by the kidneys, while Creatinine is a waste product produced by muscle metabolism and also excreted by the kidneys. This ratio is primarily used to differentiate between prerenal and renal causes of acute kidney injury (AKI). A high BUN/Creatinine ratio (>20:1) is typically suggestive of a prerenal cause such as dehydration or decreased blood flow to the kidneys, while a low ratio (<10:1) is more indicative of intrinsic renal disease or postrenal obstruction. The BUN/Creatinine Ratio is applicable to patients with suspected kidney disease or injury, or those with known renal conditions where monitoring of renal function is necessary. It is also used in the evaluation of patients with altered mental status or suspected metabolic disorders. There are no specific exclusion criteria for the use of the BUN/Creatinine ratio, but it should be interpreted with caution in patients with liver disease, malnutrition, or those on certain medications that can affect BUN or creatinine levels. It is also important to note that this ratio is

Reference

Kidney Disease: Improving Global Outcomes (KDIGO) CKD Work Group. KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney Int. 2024 Apr;105(4S):S117-S314.