13C-Methacetin Breath Test for the Prediction of Outcome in in ALI or ALF

"The test substrate in this study, ¹³C-methacetin solution for single-use oral administration (75 mg in 150 ml purified water), is administered orally or via feeding tube, rapidly absorbed, exclusively metabolized by hepatic mixed function oxidase via O-demethylation, mainly by cytochrome P450 enzyme, subtype 1A2, into acetaminophen and formaldehyde. The formaldehyde is then transformed through two successive oxidative steps to ¹³carbon dioxide, the quantity of which is measured in exhaled breath as a ratio of 13C to 12C.~The nasal or intubated breath sampling investigational device (ID) circuit continuously transports the breath sample from the patient to the BreathID® MCS device before and following administration of the 13C-methylacetanilide test substrate."