Interpretation
| BMP/ELECTROLYTES: | |||
| Na+ = 140 | Cl− = 100 | BUN = 20 | / |
| Glu = 150 | |||
| K+ = 4 | CO2 = 22 | PCr = 1.0 | \ |
| ARTERIAL BLOOD GAS: | |||
| HCO3- = 24 | paCO2 = 40 | paO2 = 95 | pH = 7.40 |
| ALVEOLAR GAS: | |||
| pACO2 = 36 | pAO2 = 105 | A-a g = 10 | |
| OTHER: | |||
| Ca = 9.5 | Mg2+ = 2.0 | PO4 = 1 | |
| CK = 55 | BE = −0.36 | AG = 16 | |
| SERUM OSMOLARITY/RENAL: | |||
| PMO = 300 | PCO = 295 | POG = 5 | BUN:Cr = 20 |
| URINALYSIS: | |||
| UNa+ = 80 | UCl− = 100 | UAG = 5 | FENa = 0.95 |
| UK+ = 25 | USG = 1.01 | UCr = 60 | UO = 800 |
| PROTEIN/GI/LIVER FUNCTION TESTS: | |||
| LDH = 100 | TP = 7.6 | AST = 25 | TBIL = 0.7 |
| ALP = 71 | Alb = 4.0 | ALT = 40 | BC = 0.5 |
| AST/ALT = 0.6 | BU = 0.2 | ||
| AF alb = 3.0 | SAAG = 1.0 | SOG = 60 | |
| CSF: | |||
| CSF alb = 30 | CSF glu = 60 | CSF/S alb = 7.5 | CSF/S glu = 0.4 |
Normal serum values
| Test | SI units | US units |
|---|---|---|
| BUN (Urea) | 7–20 mg/dL | |
| Urea | 2.5-10.7 mmol/L | |
| Creatinine | 62-106 μmol/L | 0.7-1.2 mg/dL |
Serum Ratios
| BUN:Cr | UNa | Location | Mechanism |
|---|---|---|---|
| >20:1 | >100:1 | Prerenal (before the kidney) | BUN reabsorption is increased. BUN is disproportionately elevated relative to creatinine in serum. Dehydration is suspected. |
| 10-20:1 | 40-100:1 | Normal or Postrenal (after the kidney) | Normal range. Can also be postrenal disease. BUN reabsorption is within normal limits. |
| <10:1 | <40:1 | Intrarenal (within kidney) | Renal damage causes reduced reabsorption of BUN, therefore lowering the BUN:Cr ratio. |
An elevated BUN:Cr due to a low or low-normal creatinine and a BUN within the reference range is unlikely to be of clinical significance.
Read more about this topic: BUN-to-creatinine Ratio