Rapid estimation of creatinine clearances in patients with liver dysfunction

Different methods are available for rapid assessment of renal function usin g the patient's serum creatinine concentration and body weight without obta ining urine collection over 24 hr. However, the reliability of these method s in patients with liver diseases has not been established. The purpose of this study was to determine the accuracy and precision of the estimated cre atinine clearances obtained by the methods of Cockcroft-Gault, Jelliffe, Ma wer, and Siersbaek-Nielsen in patients with liver diseases who have differe nt degrees of renal function. Creatinine clearances obtained from 24-hr uri ne collection were used as the standard. The different methods for rapid re nal function estimation had limited accuracy and reliability in patients wi th severe liver dysfunction (Child-Pugh class C) and also in those with cre atinine clearances of less than 60 ml/min. Creatinine clearances were overe stimated by about 40-100%. Using lean body weights, instead of total body w eights, reduced the prediction errors. In patients with mild liver dysfunct ion (Child-Pugh class A), all four estimation methods provided reasonable e stimation of the creatinine clearances.