cliot (version 1.0.0)

bun_creatinine_ratio: BUN/Creatinine Ratio

Description

Calculates the Blood Urea Nitrogen (BUN) to Creatinine ratio. This ratio helps differentiate between prerenal, intrinsic renal, and postrenal causes of acute kidney injury (AKI). The calculation standardizes inputs to mg/dL before computing the ratio to ensure consistent application of the 10:1 and 20:1 clinical thresholds.

Usage

bun_creatinine_ratio(bun, creatinine, bun_units = "mg/dL", creatinine_units = "mg/dL")

Value

A list containing:

BUN_Creatinine_Ratio

The calculated dimensionless ratio (based on mg/dL values).

Interpretation

Clinical classification (Prerenal, Normal/Postrenal, Intrarenal).

Possible_Causes

List of potential etiologies associated with the ratio range.

Arguments

bun

Numeric. Blood Urea Nitrogen level.

creatinine

Numeric. Serum Creatinine level.

bun_units

String. Units for BUN input. Options: "mg/dL" (default) or "mmol/L" (Urea).

creatinine_units

String. Units for Creatinine input. Options: "mg/dL" (default), "umol/L", or "mmol/L".

References

Dossetor JB. Creatininemia versus uremia. The relative significance of blood urea nitrogen and serum creatinine concentrations in azotemia. Ann Intern Med. 1966;65(6):1287-1299. doi:10.7326/0003-4819-65-6-1287

Examples

# Example 1: Prerenal Azotemia (Dehydration)
# BUN 40 mg/dL, Cr 1.0 mg/dL
# Ratio = 40 (>20)
bun_creatinine_ratio(40, 1.0)

# Example 2: Intrinsic Renal Disease (ATN)
# Urea 10 mmol/L, Cr 300 umol/L
# BUN = 10 * 2.8 = 28 mg/dL
# Cr = 300 / 88.4 = 3.39 mg/dL
# Ratio = 28 / 3.39 = 8.2 (<10)
bun_creatinine_ratio(10, 300, "mmol/L", "umol/L")