Presentation on theme: "Steve Bradley Chief Medical Resident, HMC Inpatient Services"— Presentation transcript:
1Steve Bradley Chief Medical Resident, HMC Inpatient Services Liver Function TestsSteve BradleyChief Medical Resident, HMC Inpatient Services
2What are “Liver Function Tests” Few are truly associated with functionAlbumin: protein synthetic functionINR: clotting factor synthesisMost are related to cell injuryPatterns point to specific cell injury
3Tests of Liver Injury AST/ALT Alkaline Phosphatase/GGT Cytoplasmic enzymes found in hepatocytesVery sensitive marker for hepatocyte injurySpecificity is poor (other sources, e.g. muscle)Mitochondrial isoenzymeAST increased by ethanol (explains 2:1 ratio)Alkaline Phosphatase/GGTCanicular enzymesGradual increase in plasma levels with obstruction of canicular flow
4Patterns of Enzyme Elevation Hepatocellular injuryAST/ALTCholestaticBilirubin/alkaline phosphataseMixedIsolated/predominant alkaline phosphatase elevatioin
5Caveats to Patterns Hepatocellular injury Cholestatic Also results in release of bilirubinAlkaline phosphatase also found in hepatocyteCholestaticBiliary obstruction can lead to hepatocellular injuryHistory and Physical guide your thinking!!
6Patient #1: Suzie DuziePresents with two days of fever, abdominal pain, yellow skin, nausea, vomiting.Labs demonstrate the following:AST 3210ALT 3060Alk phos 249TBili 6.2 (Direct 4.3)Albumin 3.1INR 1.2
7What targets the hepatocyte? ToxinsAlcoholMedicationsTylenolMushroomsViralHepatitis A/B/CEBV/HSV/CMVIschemiaSevere hypotensionVasoconstrictionSepsisAutoimmuneWilson’sAlpha-1 antitrypsin deficiency
8Degree of elevation points to etiology IschemiaToxinVirus>500 to 1000Acute biliary obstruction<300Alcoholic liver disease, cirrhosis, chronic obstructionAST/ALT>2 and each <300 suggests EtOH or cirrhosisIf >500, unlikely EtOH
9Back to our patient Transaminases in the 1000s IVDU Cocaine Suggests ischemia/toxin/viralIVDURisk of acute Hep B or acute Hep CCocaineRisk of ischemiaRecent infectionDoxycycline
10Patient #2: Ima Hurtin40 year-old overweight woman presents with right UQ abd pain, fever, chills. Previous episodes after fatty meals.Laboratory StudiesAST 67ALT 57Alk Phos 293TBili 4.1 (Direct 2)Albumin 4INR 1
11Increased Bilirubin Sources Conjugated=direct=processed by liver Increased productionHemolysis, hematoma reabsorptionImpaired uptake/conjugationDubin-Johnson, Gilbert’sImpaired excretionRenal failure, biliary obstructionConjugated=direct=processed by liverUnconjugated=indirect=not processed by liverFractionation – helpful to assess for unconjugated hyperbilirubinemia< 20% direct AND indirect >1.2
12Biliary Obstruction Canicular cell injury Alkaline phosphatase GGT Liver and bone major sourcesIncreased synthesis and release in liver diseaseUp to 3x normal in variety of liver diseaseGGTSensitive indicator of canicular cell injuryParallels alkaline phosphatase increase when of liver origin
13Causes of Biliary Obstruction ExtrahepaticCholedocholithiasisMalignancyCholangiocarcinomaPancreatic cancerGallbladder cancerAmpullary cancerPrimary sclerosing cholangitisAIDS CholangiopathyIntrahepaticTPNSepsisPrimary sclerosing cholangitisPrimary biliary cirrhosisIntrahepatic mass
14How would you like to approach this patient? Finding the source of obstructionUltrasound: good for extrahepatic causeCT/MRI/ERCP: for both intra or extrahepatic causeIn our patient?
15Patient #3: Biggie Smalls 46 yo man with history of IVDU and long-standing alcohol use following up in clinic.LaboratoryAST 68ALT 37Alk phos 194TBili 1.3Albumin 2.9
16Mixed Patterns of Elevated Liver Function Chronic Liver diseaseHepatitis B, Hepatitis CNASHAlcoholic liver diseaseHemochromatosisAutoimmune hepatitis
17Patient#4: Iva Fallen 72 yo man fell in bathroom. Found the next day. LaboratoryAST 167ALT 58Alk phos 127TBili 1.8Albumin 3.9
18What else do you want to know? Where else is AST and ALT found?How can you look for evidence of muscle injury?
19Additional Laboratory CK 7260Myoglobin 23390UA – 2+ blood, microscopic no RBCDiagnosis?