Measuring Creatinine Plasma Levels

By Ashley | December 16, 2009

Plasma creatinine is essentially a byproduct of the creatinine phosphate content present in muscle. Due to a chemical reaction, creatinine is an impulsively formed cyclic offshoot of creatine. The creatinine is filtered out of the blood by the kidneys, although a small amount of it is secreted by the kidneys into the urine as well. In instances where there is a malfunction with the way the kidneys filter the blood levels rise. As such, the plasma creatinine levels in the blood are generally used to calculate the creatinine clearance, which reflects the glomerular filtration rate or GFR, which is serves in gauging renal function. An informed diagnosis of renal function can be made when comparing blood plasma creatnine concentration along with that of the urea. Studies have shown that men tend to have higher levels of creatinine as a result of their higher skeletal mass than when compared to women.

Reasons For Conducting Urine and Plasma Creatinine Tests

Besides gauging renal function, testing one’s plasma creatinine levels serves to also indicate pre renal problems such as volume depletion. The urine and plasma creatinine tests are both used to gauge kidney function and are frequently ordered as part of a basic or comprehensive metabolic panel of tests that help to evaluate the body’s overall functioning. Most symptoms that indicate kidney dysfunction such as fatigue, a lack of concentration, swelling or puffiness around the ankles, and bloody or foamy urine may all prompt the examining doctor to order the test.

Procedure

The test used to measure normal plasma creatinine and its levels is a rather simple one. First, a blood pressure cuff will be placed on the upper arm while some amount of blood is collected from a vein. The skin at the area where the blood is collected from will be cleaned and sterilized before the procedure. Once the blood has been collected and stored in a sterilized tube, it will be treated with an anti coagulant chemical to prevent clotting.

Preparation

The patient will be asked by his or her doctor to abstain from any food or drink for at least 12 hours prior to the test. In case the patient is under the administration of any kind of medication, it should be informed to the attending doctor as a number of medicines have the ability to significantly interfere with tests for plasma creatinine level. Please discuss any other ailments that you may be facing as these could also affect your test results.