The Hydrogen GAS Clearance Method for Liver Blood Flow Examination: Inhalation or Local Application of Hydrogen?

Abstract

The liver, the largest gland of the body, with its many important functions such as bile production, carbohydrate storage, ketone body formation, etc., undergoes immediate changes upon lowering of oxygen supply and hepatic blood flow (HBF). SO far, reliable data characterizing the hepatic macro- and microcirculation are difficult to obtain because of methodological difficulties. Large HBF differences have been described in the literature which need further clarification especially with regard to ischemia and hemorrhage. 0f course, hydrogen gas clearance in response to hydrogen inhalation has been well-established as a method for organ blood flow determination, but in the case of liver blood flow it has certain limitation: during the washout period hydrogen molecules may flow from the gastro-intestinal tract into the portal vein. Furthermore, mean tissue and venous concentration might not always be in equilibrium during the washout process as postulated by the theory.