Patent ID: 8920334

Claim:
An analysis method for determining a functional parameter of a liver of a human or animal individual by measuring the 13 CO 2 content in the air exhaled by the individual to whom or to which a substrate has been administered, the reaction of which in the body of the individual results in the air exhaled by the individual containing 13 CO 2 , the method being carried out using a measurement device, wherein the substrate is 13 C-labeled methacetin, administered intravenously as a bolus in an amount of at least 2 mg per kg bodyweight of the individual, wherein the measurement device continuously analyzes the 13 CO 2 content in the air exhaled by the individual, the analysis being carried out as a continuous online measurement and analysis, wherein the functional parameter of the liver is selected from the group consisting of the liver function capacity and the microcirculation in the liver, wherein the liver function capacity is quantifiably determined from the maximum reaction rate of the substrate in the body of the individual, wherein the microcirculation in the liver is quantifiably determined from the inundation time, wherein the inundation time is the time needed to reach the maximum reaction rate of the substrate in the body of the individual after administration of the substrate, wherein the maximum reaction rate is determined by means of zero-order enzyme kinetics via a change over the measurement time of the measured 13 CO 2 content of the air exhaled by the individual, wherein if liver function capacity is quantifiably determined, then the maximum reaction rate is standardized by a division by the bodyweight of the individual; and if the microcirculation in the liver is quantifiably determined, then at least one of the inundation time and the maximum reaction rate is standardized by a division by the bodyweight of the individual, wherein the 13 CO 2 content is determined relative to the 12 CO 2 content in the air exhaled by the individual, and wherein the maximum reaction rate of the substrate in the body of the individual is determined by means of the following formula: LiMAx = ( δ 13 ⁢ C tmax - δ 13 ⁢ C t ⁢ ⁢ 0 ) · R PDB · P · M KG , where δ 13 C is the difference between the 13 CO 2 / 12 CO 2 ratio in the air exhaled by the individual and that of the Pee Dee Belmnite standard in delta per mil, R PDB is the 13 CO 2 / 12 CO 2 ratio of the Pee Dee Belmnite standard, P is the CO 2 production rate of the individual, M is the molecular weight of the substrate, and KG is the bodyweight of the individual.