{"type":"rich","version":"1.0","provider_name":"Transistor","provider_url":"https://transistor.fm","author_name":"Board Pearls","title":"Chapter 17, Ep 1 of 2: The R Ratio and the Two Workup Tracks","html":"","width":"100%","height":180,"duration":958,"description":"Episode one of the Liver Test Interpretation chapter turns abnormal liver enzymes into a workup by computing the R ratio and committing to a track before ordering another test. The organizing idea: which enzyme dominates and by how many multiples of normal it sits at frames the entire differential, because hepatocellular and cholestatic patterns share almost nothing. The hepatocellular track runs five layers in order (viral, autoimmune, metabolic, ischemic, drug); the cholestatic track branches on a single ultrasound finding, dilated tree or not. Thresholds, magnitude anchors, and reflex panels throughout.\n \nTopics covered\n\nThe R ratio and sorting hepatocellular from cholestatic\nHepatocellular injury and magnitude-based differential\nAST-to-ALT ratio and the redefined normal range\nHepatocellular workup: viral, autoimmune, metabolic layers\nIschemic (shock liver) and drug-induced injury with Hy's Law\nCholestatic workup and the ultrasound branch point\nIntrahepatic cholestasis: PBC, PSC, and IgG4 disease\nThe mixed pattern and the synthesis\n \n \nKey decisions\n\nCompute the R ratio first on any liver vignette: R over five is hepatocellular, R under two is cholestatic, and two to five is mixed, and commit to that track before ordering another test.\nAcetaminophen and ischemic hepatitis are the two causes that cross an ALT of five thousand; ischemia carries an LDH-to-ALT ratio over one and a half with a hypotensive precedent, while an AST-to-ALT ratio over two with AST under four hundred in a drinker is alcoholic hepatitis until proven otherwise.\nUse the current normal ALT of under twenty-five for women and under thirty-three for men, because the old range was inflated by undiagnosed fatty liver and hepatitis C.\nRun the hepatocellular workup in order: viral first (hepatitis B surface antigen and hepatitis C antibody with reflex RNA), autoimmune second (ANA, smooth-muscle, anti-LKM-one, quantitative IgG), metabolic third (transferrin saturation over forty-five percent before...","thumbnail_url":"https://img.transistorcdn.com/-FuAdDBcPDLhEoUmroZKtOBRvuBn_FHPpYlh41hOnU4/rs:fill:0:0:1/w:400/h:400/q:60/mb:500000/aHR0cHM6Ly9pbWct/dXBsb2FkLXByb2R1/Y3Rpb24udHJhbnNp/c3Rvci5mbS9iNzlh/ZTU4Y2MzNWExMjQ5/MjA5OWMwMmI3ZTk5/NGFiZS5wbmc.webp","thumbnail_width":300,"thumbnail_height":300}