Jaundice and hepatomegaly.docx

Jaundice and hepatomegaly.docx

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Jaundiceandhepatomegaly

Jaundiceandhepatomegaly

3.6Jaundiceandhepatomegaly3.6.1Distinguishbetweenprehepatic,hepaticandpost-hepaticjaundiceonclinicalandbiochemicalgroundsThebasiccauseofjaundiceisproductionofbilirubinataratefasterthathelivercanconjugateit.PrehepaticFree（unconjugated）bilirubinispresentinthebloodatmuchhigherconcentrations.Theliverworksmuchharderthannormalbutcannotkeepupenoughtofullyconjugateallthebilirubintheamountofunconjugatedbilirubinremainhigh.Theexcess（abovenormal）amountsofconjugatedbilirubinpassalongthebilecanaliculiandendsupasurobiligeninthegut.Fromhereitischangedintowatersolubleurobilinogen（bybacteria）whichisreabsorbedintotheplasmaandpassedthroughthekidnetandintourine.Urobilinogenhasnocolour.Unconjugatedbilirubinisnotwatersolubleandsocannotbeexcretedinurine.Post-hepaticthereisafaultorblockagesomewheredownstreamofconjugation.Conjugatedbilirubinfromthelivercan’tgettothegut（forexample,becausethebileductisblocked）,sospillsoverintothebloodstream.Conjugatedbilirubiniswatersoluble,andcanhencepassviatheglomerulusintotheurine,givingitacharacteristicdarkcolour.Meanwhile,thedropingutbilirubinleaveslesssubstrateforbacteriasolittleornourobilinogencanbeformed;consequentlynoneisfoundintheurine,andlittlestercobilincanbemade.Cholestasisthereforeleadstopalestoolsanddarkurine.HepaticDamagetothehepatocytesthemselvesresultsinamixedpicture.Earlyoninthediseasebothtypesofbilirubincontributetothejaundice,butasthediseaseprogressescholestasisoftensupervenesandconjugatedhyperbilirubinaemiabecomesthedominatingfeature.InsummaryPre-hepatic（Haemolytic）DarkStoolHaemoglobinReticulocytosisNNNNoneN/Hepatic（toxins,infections）Post-hepatic（Cholestatic）DarkurinePalestoolNN//NoneClinicalFBCLFTUnconjugatedbilirubinConjugatedbilirubinALPALTUrineBilirubinUrobiligenTests:

urine,FBC,UE,LFT,Serology（HAV,HBV,HCV,EBV,CMV）,clotting,bloodfilm,reticulocytecount,Coombstest（usedintheinvestigationofhaemolyticanaemia.ApositiveCoombs’testisfoundincasesofautoimmunehaemolysisduetothepresenceofIgG,complementorboth,onthesurfaceofthepatient’sredcells）.Specifictests:

serumcopperceruloplasmin（inWilsons）,serum1antitrypsin,serumironandTIBC（inhaemochromatosis）Imaging:

USS,ERCP,MRCP,CT,Liverbiopsy/N/N/N3.6.2Distinguishbetweeninfectiousandmechanicalcausesofbiliaryobstruction;3.6.3InitiateappropriateinvestigationsforbiliaryobstructionMechanicalGallstonesCancerheadofpancreasCancerhepaticCancercholecysticStricturesPSCStricturesPBSInfectiousCirrhosis-viralCT/MRI3.6.4DistinguishthecommoncausesofhepatomegalyonclinicalgroundsCirrhosisCardiacfailureEarlyGenerallyregularsurfaceNojaundiceLateGenerallyirregularsurfaceWithjaundiceOthercauses:

hepatitis,otherinfection,sarcoid,haemochromatosis,fattyliver,Riedelslobe,biliarytractdisease3.6.5InitiateappropriateinvestigationsforhepatomegalyCT/MRIFBC（withbloodfilm）CXR/AXRESR,UE,LFT,Ca2+InvestigationsLFTs:

ALPinPSCCRP/ESR:

inPSC/PBHWCC:

ininfectionSerology:

HAV,HBV,HCV,EBV,CMVUSS:

gallstones,cancer,cirrhosisERCP/MRCP:

stricturesSecondarymetastasesGenerallyirregularNojaundiceGenerallyregularNojaundiceTense,tenderliverPeripheraloedemaIncreasedJVPBiopsy3.6.6RecognisethemanifestationsofchronicliverdiseaseincludingencephalopathyandportalhypertensionLiverFunctionalbumincoagulationproteinsBileComplementoestrogenAmmoniaureaGluconeogenesis（aminoacidsglucose）StorageofglucoseasglycogenGlycogenolysisPortalhypertensionAriseinpressurewithintheportalveinanditstributaries.Resultantfromincreasedresistancetoportalbloodflowcausedbycirrhosis:

perisinusoidalcollagendeposition,perivenularfibrosis,expansionofnodules.Consequencesincludeporto-sytemicshuntinginwhichsomebloodbypassestheliverthroughanastomoseswithsystemiccirculationvesselsthisoccursatthreesites:

Betweensystemicandportalveinsoesophagealveinandleftgastricveinrectal/inferiorrectalveinsandsuperiorrectalveinsmallepigastricvofanteriorabdowallandparaumbilical*Bleedingfromthissitemayoccurthroughtheruptureofdelicateengorgedvesselsbyeatingthismayresultinhaematemesis,melaenaordeath.Otherresultsofportalhypertension:

Ascites（canalsobecausedbycongestiveheartfailure,malignancyortrauma）TransudatevsExudate:

Atransudateisafluidcontaining25mgofproteinpermlofwater.Anexudatecontainsmorethanthis.Transudatesaretypicallycausedby