BUN/Serum Creatinine Ratio Test

The bun is blood urea nitrogen. Creatinine is a natural waste that occurs at a low level in the body. Both BUN and creatinine are nitrogenous end products of metabolism, filtered by the kidney and excreted in the urine. Therefore Doctors measure the level of creatinine and BUN to check kidney and liver functions. High levels of creatinine and the BUN-creatinine ratio may indicate acute kidney injury or dehydration. Because of decreased muscle mass, elderly patients may have an elevated BUN:Cr at baseline Hypercatabolic states, high-dose glucocorticoids, and resorption of large hematomas have all been cited as causes of a disproportionate rise in BUN relative to the creatinine

Based on a few clinical indications as follows, your doctor might ask you to take up the test

• Abnormal heartbeat
• Abnormal urine production
• Altered mental status
• Fatigue
• Pale appearance
• Differentiating prerenal and postrenal azotemia from renal azotemia

No special preparation is required for the test. However, there are specific factors that could interfere with the results as follows

• Diet
• Hydration Status
• Pregnancy.
• Certain medications using herbal supplements

• Acute tubular necrosis
• Congenital deficiency of urea cycle enzymes
• Decreased urea synthesis
• Gastrointestinal hemorrhage
• Kidney disorder
• Kidney failure
• Prerenal azotemia superimposed on
• Prerenal/ Postrenal azotemia
• Rhabdomyolysis
• SIADH

The laboratory test results are NOT to be interpreted as results of a 'stand-alone' test. The test results have to be interpreted after correlating with suitable clinical findings and additional tests. Usually, a basic metabolic panel test (BMP) or comprehensive metabolic panel (CMP) is done along with BUN creatinine test

It's a simple blood test that's done by a lab technician. Only a small quantity of sample is required. The technician observes your arm for the veins visibility. Once he determines where he has to inject, he cleans the area with an antiseptic. An elastic band is wrapped around your upper arm for easy collection of blood. He slowly injects the sterile needle into the vein and draws out the blood. It shouldn't take anything more than a couple of minutes.

Slight pain is caused while drawing blood. There could be multiple punctures if the technician is not able to spot the right vein at the first attempt. The blood is immediately transferred into the blood container, which has the appropriate preservative/clot activator/anti-coagulant The syringe and the needle are disposed into the suitable 'sharps container' for safe and hygienic disposal