Intrinsic hepatic clearance and Child-Turcotte classification for assessment of liver function in cirrhosis

Abstract

Child-Turcotte classification (CTC) is an empirical but widely accepted approach for assessment of severity of cirrhosis. However, it is not known to what extent CTC reflects accurately the degree of impairment of hepatic function. In this study we compared CTC, standard liver tests and intrinsic hepatic clearance (IHC) of indocyanine green as means of assessing hepatic function in 63 cirrhotic patients. As compared to 10 control patients, IHC was significantly decreased in the cirrhotic group: (mean +/- SD) 0.270 +/- 0.141 l/min vs 1.227 +/- 0.312 l/min (P less than 0.001). Serum bilirubin (SB), prothrombin time (PT) and serum albumin were significantly correlated with the degree of IHC impairment while alkaline phosphatase, ALAT and clinical criteria of CTC were not. Multivariate analysis showed that SB and PT were the only 2 variables that significantly explained the impairment of IHC. The model which best explained IHC impairment was Z = 21.77 + 4.78 PT - 1.25 SB. The rate of IHC variance explained by this model, as determined by multiple correlation coefficient square (R2), was 42.6%. These results suggest that CTC provides only gross information about the degree of impairment of liver function in cirrhosis. To evaluate the role of liver function in the prognosis or in the response to treatments, it should therefore be preferable to employ direct measurement of liver function using a clearance technique.