Clearance tests of liver function.

Measurement of the clearance of substances removed from the circulation primarily by the liver, which depends on the uptake, storage, and excretory capacity of the liver, provides the most sensitive, specific, and reliable test for hepatic function. Since serum enzymes and other tests of liver function do not permit detection of early phase injury or provide information on progress, and since the use of sulfobromophthalein has been discontinued because of occasional fatal reactions, substitutes are necessary. Clearance of indocyanine green, bile acid, and exogenous metabolites such as galactose, protein, and aminopyrine are reviewed.