Rapid estimation of creatinine clearances in patients with liver dysfunction.

Different methods are available for rapid assessment of renal function using the patient's serum creatinine concentration and body weight without obtaining urine collection over 24 hr. However, the reliability of these methods in patients with liver diseases has not been established. The purpose of this study was to determine the accuracy and precision of the estimated creatinine clearances obtained by the methods of Cockcroft-Gault, Jelliffe, Mawer, and Siersbaek-Nielsen in patients with liver diseases who have different degrees of renal function. Creatinine clearances obtained from 24-hr urine collection were used as the standard. The different methods for rapid renal function estimation had limited accuracy and reliability in patients with severe liver dysfunction (Child-Pugh class C) and also in those with creatinine clearances of less than 60 ml/min. Creatinine clearances were overestimated by about 40-100%. Using lean body weights, instead of total body weights, reduced the prediction errors. In patients with mild liver dysfunction (Child-Pugh class A), all four estimation methods provided reasonable estimation of the creatinine clearances.