DOI: 10.21276/sajp

Pages: 168-170

Serum creatinine is widely used in the assessment of renal function to detect and prognosis of conditions with impaired renal function. Serum creatinine is a convenient test, but it has several limitations to interpret renal function. Glomerular filtration rate (GFR) estimation uses serum creatinine levels along with other variables, but still it can be erroneous due to many confounding variables. Extensive efforts by scientific community improved specificity of the creatinine assays and standardized it across different laboratories. Sensitivity of serum creatinine in severe renal impairment is better in relation to poor sensitivity in detection of early damage. Diseases of the kidney will increase tubular secretion and extra-renal elimination of creatinine. Several drugs block, tubular secretion of creatinine. Changes in muscle mass and protein metabolism significantly affect serum creatinine levels. A combination of serum creatinine and serum cystatin C was found to be less erroneous as the confounding factors for both shall not be the same. Limitations of serum creatinine levels should be considered while making relevant clinical decisions in a patient with renal impairment.