Assessment of Glomerular Filtration Rate and Kidney Dysfunction in Patient with Cirrhosis

It is important to accurately assess the glomerular filtration rate (GFR) of patients with liver cirrhosis to deliver care, especially in the context of intensive care unit (ICU) with adaptation of drugs' posology, and allocate organs for transplantation in a way that improves outcomes. The most commonly used methods to estimate GFR in this population are based on creatinine, which is biased by their low creatinine production and potentially by elevated serum bilirubin and decreased albumin levels. None of the creatinine-based estimated glomerular filtration rate (eGFR) equations has been specifically modified for a population with cirrhosis, and even measurement of a 24-hour creatinine clearance has limitations. In this condition, all creatinine-based estimates of GFR overestimate gold standard-measured GFR, and the degree of overestimation is the highest at lower measured GFR values. Cystatin C-based eGFR has shown promise in general population studies by demonstrating less bias than creatinine-based eGFR and improved association with clinically important outcomes, but results in the liver disease population have been mixed, and further studies are mandatory. Specific eGFR equations for liver disease or novel methods for estimating GFR may be necessary. Ultimately this point is of major importance in managing hepatorenal syndrome in the ICU, since its definition, partially based on creatinine value, is highly questionable.