How to evaluate renal function in stable cirrhotic patients

Chronic kidney disease (CKD) is a disorder frequently suffered by cirrhotic patients, and therefore it is crucial to perform an accurate renal assessment in this population. This assessment should be based on the integral evaluation of the clinical exam, glomerular filtration rate (GFR), serum electrolytes, hemoglobin, and parathyroid hormone values, as well as urinalyses and renal imaging. GFR assessment can be performed by different methods, such as serum creatinine, serum cystatin C, GFR equations (based on creatinine, cystatin C or both), endogenous and exogenous markers clearance, and renal functional imaging. All these evaluating methods have their particular characteristics, advantages and disadvantages. Even though Cr-51 EDTA clearance seems to be the best gold standard method, creatinine-based equation (RFH cirrhosis) and cystatin C based-equations (CKD-EPI and Stevens) seem to be the most inexpensive and accurate equations, respectively, for evaluating GFR in this population. In conclusion, renal assessment in cirrhotic patients is a complex task that should not be based on a single renal functional marker.