How is progressive kidney failure identified?
Progressive kidney failure is recognized by an increasing serum creatinine over time.
However, some patients may have a normal creatinine early in the course of their chronic kidney disease (CKD). Individuals with an abnormal urinary sediment (e.g., proteinuria or hematuria) or abnormal pathology on a kidney biopsy are at risk for progressive kidney failure.
Because serum creatinine is a reflection of muscle mass, a person with low muscle mass can have CKD despite a creatinine in the normal range.
Conversely, patients with larger muscle mass may have an abnormally elevated creatinine despite normal kidney function.
For these reasons, calculating an estimated glomerular filtration rate (eGFR) is the recommended way to assess kidney function (see chapter on Glomerular Filtration Rate).
These equations should not be used in acute kidney injury because the calculations assume a stable serum creatinine.
