Gastroenterology (Medical Abdo) Notes



Gastroenterology (Medical Abdo) NotesLiverPalpable liver edge:NormalHepatomegalyLung hyperexpansionFriction rubs:1Y and metastatic malignanciesPost-liver biopsyInfective and inflammatory conditionsVenous hum:Portal venous HTNArterial bruit:Liver tumoursAlcoholic hepatitisSmall liver:CirrhosisFulminant hepatic failureChronic liver diseaseHepatomegaly:Massive:Alcoholic fatty infiltrationMyeloproliferative disordersMetsHepatomaR heart failureModerate:HaemachromatosisCML / lymphomaDiabetic fatty liverTropical disease (eg. malaria, schisto)Mild:Infections (eg. EBV, CMV, hep)Hydatid diseaseSarcoid / amyloidSplenomegaly:Massive:CMLMyelofibrosisMalaria (acute)Kala azarModerate:Portal HTNLymphoma / leukaemiaThalassaemiaStorage diseaseSchistosomiasisBrucellosisTyphoidMild:Infections (eg. EBV, CMV, SBE)Haemolytic anaemiaPolycythaemia rubra veraCT disorders (eg. RA, SLE, PAN)Sarcoid / amyloidChronic liver disease: Limbs:Duputren’s contracturePalmar erythemaClubbingEasy bruisingScratch marksPeri oedemaMetabolic flapHead:JaundiceParotid enlargementXanthomata (1Y bil cirr, scelr cholang)EncephalopathyChest:GynaecomastiaSpider naevi (>5 abnormal)Abdo:Dilated superficial veinsAscitesSplenomegalyHepatomegalyPortal HTN:SplenomegalyVenous collateralsAscitesMurphy’s sign:Inability to deep inspire due to RUQ pain= acute cholecystitis: sensitivity 97%, specificity 50%Kehr’s sign:Severe L shoulder tip pain esp when lying supine= haemoperitoneumCullen’s sign:Periumbilical ecchymoses= retroperitoneal haemorrhageGrey-Turner’s sign:Flank ecchymoses= retroperitoneal haemorrhageMcBurney’s sign:Tenderness 2/3 distance from umbilicus to R ASIS= appendicitisIliopsoas sign:AP on extension of R hip= appendicitis: 16% sensitivity, 95% specificityObturator’s sign:AP on internal rotation of flexed R hip= appendicitisRovsing’s sign:RLQ pain and palpation LLQ= appendicitisHeel-drop sign:RLQ pain on dropping heels to ground when on tiptoe= appendicitis: 93% sensitivityCough test:AP after cough= appendicitis: 95% sensitivityGastroenteritis3+ abnormally loose BM’s over 24hrsSx: vomiting ++ if pre-formed toxin; prominent AP if invasiveDoses: Norfloxacin 400mg (10mg/kg) PO BD 5/7 - E coli, Campylobacter, Alternative: ciprofloxacin, cotrimoxazole, ampicillin Yersinia, salmonella, shigellaDoxycycline - Cholera Alternative: tetracyclineMetronidazole 400mg (10mg/kg) PO TID 7-10/7 - C diff, giardiaVancomycin 125-250mg PO QID 10/7 - Severe C diffErythromycin 500mg (10mg/kg) PO QID 5/7 - CampylobacterMOIncbnDOASourceSpecific symptomsAntibiotics?Pre-formed toxinBacillus cereus1-6hrs<24hrsRice, cereal, soup, veggies, meats, pastaVomiting ++May be delayed onset form At 8-18hrs, AP + D but little VNoStaph aureus1-6hrs<24hrsCold foods, sweetened dairy productsVomiting ++ diarrhoea, AP dehydrationNoPost-formed toxinE Coli (20-75%)(Most common cause of traveller’s diarrhoea)Varies (usually 1-5/7)Days-wksMany raw foods0157:H7 Shiga bloody watery stools without WBC TTP, HUSDebatableNorfloxacin if severe (but may CAUSE HUS)Clostridium perfringens(25% all bacterial)6-12hrs<24hrsMeat and poultry, soil, manure, sewageDiarrhoea, APVibrio cholera(0-30% travellers)Hrs-days2-7/7ShellfishSevere rice water diarrhoea, headache, N+VDoxycycline if in 1st 48hrsC difficileToxins A and B; secretory1-25% colonisation in hospitalized patients7-10/7 after ABxAntibiotics ClindamycinAmpicillinAmoxicillinCephalosporinSevere:Pseudomembranous enterocolitis (RF inc recent ABx, recent GI surgery, co-morbidities, chemo, old age)or any 2 of: >60yrs; T >38.4, alb <2.5mg/dL; WBC >15Fulminant (3-8%):Toxic megacolon, systemic manifestations (eg. incr WBC, hypotension, MOF, anascara)1-3% get toxic megacolon or perfRelapse in 10-25%Stop offending ABxYES NEEDS ABX: Metronidazole Vancomycin if severeEmergency colectomy if fulminantListeriaDays - wksMeat, cheeseFlu like meningitis, septicaemia, miscarriage, prem birthBad if pregnant / neonate / immunosupp / elderlyEnteroinvasiveSalmonella(0-33% travellers)12-24hrsUp to 3/52Dairy, eggs, raw meat, raw veggiesCan cause bloody diarrhoea, systemic illnessIn children can cause osteomyelitis, meningitisIf septicaemia / immunocompromised / infant / elderly / multiple co-morbidities Norfloxacin if severe IV ceftriaxone if <3/12Shigella2-30% travellers(also release cyto, neuro and enterotoxins)12-96hrs4-7/7Infected food-handler or water; poor sanitation; traveller; child care centresDysentry: Bloody mucusy stools and tenesmus, systemic illnessSeizures, perf, HUS, Reiter’s syndrome, fulminant toxic encephalopathyYES NEEDS ABX: As public health measureNorfloxacin if severe IV ceftriaxone if <3/12Campylobacter Jejuni(3-17% travellers)2-5/72-5/7Poultry, milk, pets with diarrhoeaCan cause bloody diarrhoea, systemic illness; can cause severe AP with little diarrheaCan cause reactive arthritis, GBS, seizures, Reiter’s syndrome, neonatal sepsisIf severe / prolonged / food-handlerErythromycin / norfloxacin E coli(0-6% in travellers)Varies (usually 1-5/7)Days-wksMany raw foodsBloody diarrhoea and severe AP, systemic illnessDebatableNorfloxacin / co-trimoxazole / amox if severe Vibrio parahaemolyticus12-24hrs1-7/7ShellfishMod severity gastroYersinia enterocolitica3-7/71-21/7Pork and chickenBloods and pus in stool, severe AP (may mimic appendicitis)May cause reactive arthritis, erythema nodosum, scarlatiform rash, GN, conjunctivitis, hepatic/splenic abscess, meningitis, osteomyelitisRisk of bacteriaemia and metastatic infection if immunosuppIf immunocomp / systemically unwellCotrimoxazole / ciprofloxacin Vibrio vulnificusRapid deterioration with fever, hypoT, V+D, haemorrhagic bullous rash necrotic ulcersBroad spectrum ABxViralNorovirus(most common viral cause)12-48hrs12-60hrsShellfish; maybe infected food handlerVomiting in children, diarrhoea in adultsNoRotavirus (most common cause in children)(0-36% in travellers)24-72hrsUp to 1/52Food-handler / waterGastroNoParasiticEntamoeba histiolytica2-4/52Wks – mthsFood handler / waterCan cause bloody / mucusy diarrhoea, systemic illnessBloody stools without WBCMetronidazole + iodoquinolCryptosporidium1-12/72-21/7Food handler / waterProfuse watery diarrhoeaIf severe / immunocompromisedGiardia lamblia1-3/52>1/52 diarrhoeaFood-handler / waterHistory of rural hiking; contaminated drinking waterMild; flatulence, sulphurous belching, bloating, abdo cramps; trophozoites and cysts in stoolPale, foul, greasy poo for >1/52YES NEEDS ABX: Metronidazole 2g (child: 30mg/kg) OD 3/7 Pathology Invasive cell damage and incr secretion1) Decreased intestinal absorption – healthy SI absorbs 75% of fluid, LI absorbs 90%; usually <100ml/day lost in stool; fluids absorbed passively with Na and actively with Glu; Large vol suggests SI pathology, small vol suggests LIEnterotoxins: block Na absorption, stimulate Na secretion net loss of fluid. Don’t affect Glu absorption, therefore add Glu to rehydration fluidInflammation / ischaemia – affect villi responsible for absorptionIncreased osmotic loadDraws fluid into lumenWill be associated with certain foodsIncreased intestinal secretionUnopposed crypt secretion – unaffected by inflammationPersists with fastingAbnormal intestinal motilityOccurs in IBS, short gut syndromeRF’s: achlorhydria, bowel stasis, immunodef, recent ABxTraveller’s Diarrhoea – usually don’t need ABx as usually self-limiting; treat with norfloxacin 800mg (20mg/kg in child) PO single dose, or azithromycin 1g (child 20mg/kg) PO single doseUsually due to consumption of contaminated food and drink; educate about boiling water etc…Bacteria (80%)E coli (Mexico, S America)Salmonella (S Asia)Campylobacter (S Asia)Shigella (S Asia)ProtozoaGiardia Cryptosporidium Entamoeba histolytica Viral Rotavirus, norovirusImmunocompromised causes: cryptosporidium, microsporidium, isospora, CMVReiter syndrome: arthritis + conjunctivitis + urethritis/cervicitis = Salmonella, Shigella, Campylobacter, YersiniaInvestigationsStoolMicroscopy and culture – look for bacteria; low yield; indicated if child, toxic, dehydrated, illness >3/7, blood/pus in stool, immunocompCysts, ova, parasites – if traveler, >7/7 illness; may need multiple samples, as again low yeildWright stain for fecal leucocytes – if +ive, more chance of invasive pathogenAnalysis for C. diff toxin – if recent ABx or hospitalisationElectron microscopy, PCR, ELISA or latex agglutination to look for virus or C diff toxins; may need multiple samplesColonscopy: yellow plaques in C diff pseudomembranous colitis, usually in R colon; not routinely required to make diagnosisAXRIf recent surgeryDrug levels, TFT’sNon-infectious causes of diarrhoea: IBS, mesenteric ischaemia, thyroid storm, toxins (esp. cholinergic), adrenal insufficiency, drugs (eg. erythromycin, laxatives, antacids, oral contrast, lactulose, sorbitol, NSAIDs), GI bleed, acute radiation syndromeIf fecal evidence on inflammation and rule out Shigella, Salmonella, Campylobacter, C diff and Entamoeba histolytica – then need to consider IBDTrtMildDrink 30-50ml/kg over 4 hrsModDrink 100ml/kg over 4 hrsAvoid chewing gum, raw fruit; avoid sugary drinks (hyper-osmolar and no electrolytes incr fluid losses); avoid caffeine (incr cAMP worsened diarrhea); avoid milk (transiently lactose intolerant)Attempt early solid food intakeEducate about food hygiene. Give sick note if work in health care / with food.Cipro 500mg BD for 1/52 has been shown to shorten duration of infectious diarrhea 2Y to bacteriaHepatitisAcute = self limited liver inj <6/12Chronic = diagnosed on pathological criteria, >6/12Incubation pre-icteric icteric convalescentALT > AST (AST > ALT in cirrhosis); ALP normal or mild incrIncubation /TransmissionAcute infectionFulminant / Carrier / ChronicSerum MarkersTreatmentA2-6/52Fecal-oral (contaminated food and water, overseas travel)Rarely parenteralReportable diseaseProdrome for 1/52 mild-mod jaundice, N+V+AP, tender hepatoM, dark urine, clay coloured stools recovery over 1/12Extrahepatic: vasculitis, ARF, pancreatitis, transverse myelitis, seizures, aplastic anaemiaInfectious: from 2/52 before jaundice 1/52 after onset jaundice20% get relapse; >80% children asymptomaticFulminant: <1%Chronic: NoCarrier: NoIgM-anti HAV = acute infection; detectable 1st at onset of Sx, 3/52 post-exposure; remains for 3-6/12IgG-anti HAV = past infection and immunity; peaks 3/52 after IgMHAV RNA = in stool/plasma for most of asymptomatic period; disappears soon after onset of SxSupportiveGive inactivated vaccine if contact with case, within 2/52 exposure (nearly 100% effective)Give NPIG if <1yr, immunocomp, CLF, CI to vaccine (80-90% effective)B2/12Parenteral15% risk of transmission with sex2-30% risk seroconversion in needle-stickAcute = HBsAg and HBeAg, IgM-anti HBcAgSymptomatic acute infection in 30%; Arthritis, fever, skin eruption in preicteric phase; most common hepatitis cause of ALF; mortality higher in ALF caused by Hep B than Hep AHBsAg = acute, detectable 1st in preicteric phase; may have normalized if late presentation; carrier if present on 2 occasions >6/12 apartIgM-anti HBcAg = acute; high infectivityHBeAg = acute and phase 2 chronic (usually decreases in 3-4/52); high infectivity; marker of viral replicationFulminant: 0.1-0.5% (mortality rate 80%)Chronic: 5-10% (1-3% healthy adults, 5-10% immunocomp, 90% neonates) = HBsAg >6/12, IgG-anti HBcAg, maybe HBeAg, anti-HBeAg cirrhosis and hepatocellular Ca; shortens life span in 45% men, 15% womenPhase 1: immune tolerance; 20-40yrs; normal ALT; high levels viral replication; no trtPhase 2: immune clearance with immune response; symptomatic in 30%; hepatitis, incr ALT fibrosis with repeated episodes; cirrhosis in 30-40% Phase 3: immune control immune response suppresses replication decr inflamm, ALT normalises; 5-10%/yr phase 2 become phase 3; assoc with HBeAg seroconversion (anti-HBeAg develops, decr HBeAg); hepatitis stops; may reactivate at any timePhase 4: immune escape; recurrence of hepatitis, fibrosis; virus mutates and stops making HBeAg; incr ALT; 8-10%/yr develop cirrhosisIgG-anti ABcAg = chronic, previous infectionAnti-HBeAg = phase 3 chronic; low infectivity; indicates viral replication as ceasedHBV DNA: high infectivity, used for monitoring response to trtCarrier: 1-10% = HBsAgAccounts for 90% chronic infectionsIgG-anti HBsAg = immunity and recoveryCurrent acute infection:HBsAgHBeAgIgM-anti HBcAgHep B DNACo-infection:HBsAgHBeAgIgM-anti HBcAgHep B DNAAnti-D virusChronic active Hep B:HBsAgHBeAgIgG-anti ABcAgHep B DNAPrevious resolved Hep B: Anti HBsAgAnti-HBeAgIgG-anti ABcAgCarrier:IgM-anti HBcAgVaccinated: Anti-HBsAgSupportiveTrt if infected and abnormal LFT’s or high HBV DNA levels (likely in acute, phase 2 + 4 chronic) – entecavir, lamivudine, tenofovir etc…Vaccine available (HBsAg)If non-immune exposed, give anti-HBsAg within 1/52 (75% effective)C2/12Parenteral80% prevalence in IVDU15% rate of transmission with sex (rare)10% unknown source<2% seroconvert with needlestickAcute = HCV RNA: Pre-icteric non-specific; usually asymptomatic (Sx in 15-20%) icteric phase for 1-2/52; Extrahepatic Sx in 75%: arthralgia, paraesthesia, myalgia, pruritis, sicca spontaneous resolution in 30-50%Fulminant: RareChronic = IgG-anti HCV: 75-85% adults; 55% children25% develop cirrhosis over 20-30yrs; 20% cirrhotics develop hepatocellular CaCarrier: 0.2-1%HCV RNA = acute, detectable 1st within 1-2/52 exposureIgG-anti HCV = chronic; +ive by 3/12 usuallySupportiveInterferon if persistently high LFT’s (effective in 1/3); peginterferon + ribavarin (effective in 50%)No vaccine / post-exposure prophylaxis availableD4-7/52ParenteralSexual rareUsually IVDU Only occurs in patients with acute/chronic HBV5% HBV carriers have HDVAcute = HDV RNA, Ig-anti HDV: in 2-20% Co-infection – hepatitis with resolution in 80-95%Fulminant: 2-20% if super-infectionChronic = Ig-anti HDV: 5-10% if co-infection; 80% if super-infectionCarrier: Low1-10% IVDU and haemophiliacs are carriersHDV RNA = acuteCo-infection = IgM-anti HDAg + IgM antiHBcAg Super-infection = IgM-anti HDV + HBsAgIgM/G-anti HDV = acute / chronicSupportive; interferon may helpOtherwise as per HBVE2-8/52Fecal-oral, water-bourneAcute = HEV Ag, IgM-anti HEV: Self-limited; 1-3% overall fatality; 5-25% mortality in pregnancyFulminant: 20% if pregnantChronic: NoCarrier: NoHEVAg = acuteIgM-anti HEV = acuteIgG-anti HEV = immunitySupportiveVirusAcute infectionChronic infectionImmunity and recoveryCarrierAHAV RNA IgM-anti HAVNoIgG-anti HAVNoBHBsAg IgM-anti HBcAg, HBeAg5-10%IgG-anti ABcAg, HBeAg (phase 2) Anti-HBeAg (phase 3)IgG-anti HBsAg1-10%HBsAgCHCV RNA75-85%IgG-anti HCV0.2-1%DHDV RNA IgM-anti HDVCo-infection = IgM-anti HDAg + IgM antiHBcAg Super-infection = IgM-anti HDV + HBsAg5-10%IgG-anti HDVLowEHEVAg IgM-anti HEVNoIgG-anti HEVNoOther causes: ETOH; non-alcoholic steatohepatitis (10-50% develop cirrhosis); drug induced (necro-inflammatory eg. Paracetamol; cholestatic eg. Chlorpromazine); autoimmuneHepatorenal SyndromeDevelopment of ARF in patient with normal kidneys in presence of preexisting A or CLF; cause unknownType IMore serious; progressive oliguria; Cr x2 in 2/52; survival without medical trt <1/12Type IIGradual impairment of renal functionToxic MegacolonDefintion: non-obstructive colonic dilation with fever + abdo distension + severe AP + shock; distension can be segmental / totalPathophysiology: NM tone decr 2Y to transmural inflammation; abnormal if >6cm; transverse colon most commonly affected; occurs in IBD, but also in Crohn’s (also in ischaemic bowel, pseudomembranous colitis, radiation colitis, infectious colitis, Hirschsprung diseaseRF’s: precipitated by hypomotility agents (eg. Loperamide), Ba enema, hypoK, opiates, anticholinergics, pregnancy, enema, recent colonscopySx: severely ill, fever, profuse diarrhea, hypoV, incr HR, abdo distension, severe pain, tenderness and peritonitis, N+V, rectal bleeding may occur; Sx may be masked by steroidsComplications: perforation, circulatory collapse, septicaemiaInvestigation: Bloods (FBC, U+E, glu, lipase, LFTs, cultures, ABG, ESR, CRP); XR (loss of haustra, thumb printing, air filled dilated segments of colon >6cm); CXR (for perf); ECG; scope (carries risk of perf); CT (for complications like abscess and perf); effectiveness of scope screening controversialMng: admit if severe disease, suspected complications; response assessed by serial XRIVF: as indicatedAnalgesiaNG, NBMSulfasalazine: 1-4g/day; for mild-modMesalazine: better tolerated, equally effective, can be given PRAntibiotics: for severe disease; ampicillin / gent + clindamycin / metronidazoleSteroids: pred 25-50mg; hydrocort 100mg Q6h; enemas / IV / POImmunoS: if refractory; azathioprine, ciclosporin (may avert need for OT), tacrolimus, infliximabTotal colectomy: if drug resistant (ie. No response in 24-48hrs)Prognosis: >30% mortality; 15yrs disease 12% risk of Ca, 20yrs 23%, 25yrs 42%, risk greatest with pancolitis ................
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