If the intrinsic control of the liver is responsible for these changes it would be important to show that the liver is more metabolic as the changes occur. An intervention to lower the metabolic demand on the liver is difficult and may not be ethical given that the normal response to injury or infection is an acute phase response. One area where this could be said to have been performed is the tight control of blood glucose in intensive care medicine which reduces the demand on the liver to perform gluconeogenesis. While there are other benefits of lower serum glucose levels this may contribute to the reported improved outcome in such patients. Clinically, measurement of hepatic arterial and portal venous blood flow has been shown to be feasible in the critically ill patient and may be used as a non-invasive measurement of the liver response to a drug or therapy.