Blood

Adult: 15-45 µg/dl Child: 29-70 µg/dl Infant: 90-150 µg/dl

To evaluate or monitor severe liver failure, hepatoencephalopathy To monitor the effects of impaired portal vein circulation

Liver failure Cirrhosis Hepatoencephalopathy Portal Hypertension Aminoaciduria Reye's Syndrome

Tobacco smoke High protein intake Gastrointestinal hemorrhage Hyperalimentation