Gastroenterology/Hepatology Flashcards
Mortality and recurrence for SBP?
Both high!
Causative organisms for SBP?
90% enteric e.g. E. coil, Klebsiella, Enterococcus
Pathophysiology of PBC?
Chronic granulomatous inflammation of small intra-hepatic ducts with progressive cholestasis, cirrhosis and portal HTN. Onset of jaundice is late sign and poor prognostic factor.
Abs in PBC?
98% are positive for AMA
Treatment of PBC?
Colestyramine and UDCA; only curative is OLT. UDCA does however reduce rate of progression to liver failure (reduces total bile acid pool)
Patho of PSC?
Non-malignant, non-bacterial inflammation and fibrosis of the intra- and extra-hepatic biliary tree. Common in men, frequently in UC.
Diagnosis of PSC?
MRCP or ERCP showing beaded appearance
Abs in PSC?
ANA, ASMA and ANCA may be positive, AMA is negative (unlike PBC)
Presentation of AIH?
25% with acute hepatitis or signs of fulminant AI disease e.g. rash, fever, malaise. The remainder present insidiously
Abs in AIH?
Three subtypes.
- = ASMA positive
- = anti-LKM (liver kidney microsomal)
- = anti-SLA (soluble liver antigen)
Risk factors for ascending cholangitis?
Biliary instrumentation e.g. ERCP, stents
What are biliary stents used for?
Treatment of obstructive jaundice in in-operable patients
Most common causative organisms for ascending cholangitis?
E. coli, Klebsiella, Enterobacter
What does the marginal artery of Drummond do?
Connects SMA and IMA
Three main branches of coeliac trunk?
- Common hepatic (branches to hepatic artery proper, right gastric and gastroduodenal)
- Left gastric artery (oesophageal and stomach branches)
- Splenic artery (short gastric branches)
Risk factors for glutathione depletion (and therefore paracetamol OD?)
Malnourishment, eating disorders, FTT/CF, AIDS, cachexia, alcoholism. Also enzyme induction by regular alcohol consumption or inducing drugs
Patho of paracetamol OD?
NAPQI formed when paracetamol oxidised. Glutathione conjugates this but is depleted (is natural anti-oxidant)
Extra-intestinal features of IB?
- Oral (ulcers [Crohns])
- Eyes (anterior uveitis, conjunctivitis and episcleritis)
- Joints (seronegative spondyloarthritis, sacroilitis, migratory polyarthritis)
- Skin (pyoderma gangrenosum [UC}, erythema nodosum, erythema multiforme (not CD), clubbing)
- Liver (PSC [UC])
- Anal (fissures)
Features of psoriatic arthritis?
Bilateral, symmetrical, deforming arthopathy of hands (as with RA) Can get dactylitis and arthritis mutilans.
Features of rheumatoid arthritis?
Bilateral, symmetrical, deforming arthopathy of hands. Can get joint erosions, ulnar deviation (subluxation), Z-thumb, swan-necking and boutoniere’s
Pattern of pain in diverticular disease?
Worsened by eating, relieved after bowel emptying
Complications of diverticular disease?
Abscess, perforation, obstruction
Features of carcinoid syndrome?
Carcinoid tumours are neuro-endocrine, serotonin-secreting, most frequently in TI. Primary often asymptomatic. If serotonin produced cannot be broken down by liver, get bronchospasm, diarrhoea, facial flushing, RHS valvular disease. Diagnose with raised 5-HIAA (serotonin metabolite). Treatment includes surgery, octreotide (somatostatin analogue)
Innervation of lower 1/3 of oesophagus?
Vagus (para) and sympathetic trunks
Where is copper deposited in Wilson’s?
Liver, basal ganglia, cornea hence signs inc. tremor, dementia.
Investigations in Wilsons?
Low serum copper, low caeruloplasmin, urinary copper increased, liver biopsy shows increased leels.
Treatment of Wilson’s?
Lifelong penicillamine as chelating agent, zinc as second line
Patho of A1AT deficiency?
A1AT inhibits enzymes from inflammatory cells. Get cirrhosis and respiratory pathology
Inheritance of haemochromatosis?
AR
Rx of haemochromatosis?
Venesection, OLT eventualy if severe
Penetrance of haemochromatosis?
Low. Few homozygotes will show symptoms, fewer still get cirrhosis
Treatment for NAFLD?
Weight loss, but not rapid as this increases fibrosis
Treatment of AIH?
Oral steroids, can add in azathioprine
What should be suspected in coeliac patients who initially respond to gluten-free diet then recur?
T-cell intestinal lymphoma
McBurney’s point is where?
A third of the way from ASIS to umbilicus. Landmark for location of appendix in most people. May not have tenderness here if appendix is retrocaecal or pelvic
Tinkling vs absent bowel sounds?
Tinkling suggests mechanical obstruction, absent suggests ileus
Features of Plummer-Vinson?
Progressive dysphagia, IDA, glossitis (get oesophageal webs). Treatment is iron replacement
Conditions predisposing to B12 deficiency?
Strict vegans and those with terminal ileum disease e.g. Crohns, coeliac, PA, chronic pancreatitis
Presentations of B12 deficiency?
Glossitis (beefy red tongue), jaundice, depression, psychosis, neuro e.g. peripheral neuropathy and combined degen. of SC
Management of b12 def?
If cause is dietary, then oral B12 supps; if malabsorption then IM
Which patients get hypomagnasaemia?
Severe diarrhoea, diuretic use, alcoholism, long-term PPI
Presentation of hypomagnasaemia?
Ataxia, parasthesia, seizures, tetany
Crypt abscesses are associated with?
UC!
Complications of long-term UC?
Colorectal cancer, toxic megacolon, PSC
Microscopic appearance of Crohns?
Mixed acute and chronic transmural inflammatory infilitrate with non-caseating granulomas
2ww for oesophageal/gastric cancer?
- Dysphagia
2. 55 and over, with weight loss and one of upper abdomina pain, reflux, dyspepsia
Management of Mallory-Weiss?
If stable and improves, can discharge. Do not need further investigation
Rule of 2s for Meckel’s?
2% of population 2 inch-long diverticulum projecting from ileum 2 feet from IC valve 2 times more common in men than women 2 or more types of tissue can be present
What is Meckel’s a remnant of?
Vitello-intestinal duct
How does Meckel’s present?
Mostly asymptomatic, but can cause bowel obstruction, perforation or bleeding. This occurs because contains ectopic tissue such as gastric mucosa so secretes acid and ulcerates. DD appendicitis; must be excluded if appendix normal.
Raised anti-endomysial antibody?
Seen in coeliac
How does coeliac present?
Bloating, diarrhoea, weight loss, anorexia
Patho of coeliac?
Get chronic inflammation causing flattened villi and malabsorption, as have cross-reactivity between Abs to gluten and gliadin and SB antigens
What are anti-Jo Abs associated with?
Dermatomyositis and polymyositis
RFs for oesophageal cancer?
Smoking, alcohol, Barrett’s, Plummer-Vinson
What are the three Hep B antigens?
Surface (HBsAg), core (HBcAg), envelope (HBeAg). Surface tells you about disease/immunity, core not involved in active infection. Envelope results from breakdown of core antigen. Thought to imply high infectivity
Hep B serology?
Positive HBsAg titre means acute or chronic infection. Anti-HBs = immunised or resolved infection.
Anti-HBc is not protective but useful for timing. Anti-HBc IgM rises after 2 months and drops after six; IgG becomes positive after 4-6 months an remains positive lifelong i.e. chronic infection
Difference between incubation and chronic infection profiles for Hep B?
Both would have positive HBsAg and HBeAg, negative anti-HBsAg and anti-HBeAg. But IgG and IgM to HBcAg negative in incubation, while IgG is positive in chronic infection
What are ASCA and pANCA and relation to IBD?
ASCA is anti-Saccharomyces cerevisiae antibodies; present in serum of Crohns. p-ANCA associated with UC. Can be useful in diagnosis (especially where unclear)
What is abetalipoproteinaemia
AR disorder where lipoprotein synthesis is defective. Get fat malabsorption so deficient in fat-soluble vitamins (A, D, E, K). Vit E deficiency gives neuro symptoms (ataxia, cognitive decline). Vit A gives visual problems too. Vit D gives low calcium and phosphate.
How does methanol toxicity present?
Neuro: drowsiness, headaches, dizziness, ataxia, confusion. Later, get visual problems. Classically from drinking antifreeze. Get metabolic acidosis with high anion gap and low bicarb.
Treatment of methanol toxicity?
Fomepizole
Triad of Wernicke’s
Ataxia, opthalmoplegia, confusion. Preservation of pupillary responses
Presentation of Budd-Chiari?
Acute abdominal pan, rapidly developing ascites, elevated liver enzymes, enlarged caudate lobe on ultrasound, tender hepatomegaly. If IVC obstructed get prominent venous collaterals in the back and bipedal oedema
What is Budd-Chiari?
Hepatic venous outflow obstruction; thrombosis usually in hepatic vein but can be from hepatic venules to IVC entrance at RA
Management of Budd-Chiari?
Less severe = anticoagulation. Second line is angioplasty/thrombolysis.
Third line is TIPSS
Severe or refractory = OLT
Simultaneous ?pneumonia and biliary features?
Biliary disease can cause reactive effusion and pneumonia secondary to atelectasis of lower airways so exclude this first
Three things that stimulate gastric acid secretion?
ACh, gastrin, histamine
Three things that inhibit gastric acid secretion?
Somatostatin, secretin, cholecystokinin
Most common cause of nodular hepatomegaly?
Liver mets (from bowel or breast). Often only affect LFTs if over 50% involved or obstruct biliary tract
Pseudopolyps are associated with?
UC
Anti-dsDNA?
Associated with SLE
Two regions endemic for Hep B?
Sub-Saharan Africa, East Asia
Treating bleeding ulcer?
Injected with adrenaline and clipped
Complications of ERCP?
Acute pancreatitis, oesophageal perforation, anaphylaxis, papillary stenosis (late complication), duodenal pneumatosis
Dietary advice for IBS?
Restrict caffeinated and fizzy drnks, no more than 3 fresh fruit, reduce insoluble fibre, eat small & frequent meals, decrease sorbitol
Side effects of azathioprine?
Pancreatitis, leukopenia, abnormal LFTs
Why is azathioprine a poor initial choice to induce remission?
Takes 6-10 weeks to take effect
Treating exacerbation of Crohns?
If systemically well, can give oral steroids. If unwell, with more abnormal inflammatory markers, then admit for IVT, IV steroids and electrolyte replacement. Surgery in patients refractory to medical management.
Features of dyspepsia that require urgent endoscopy referral? (ALARMS55)
Anaemia Loss of weight Anorexia Recent onset of progressive symptoms Melaena Swallowing difficulty (dysphagia) 55 = >55 years old
Test for SIBO and precaution? And gold standard test?
Small intestinal bacterial overgrowth - do hydrogen breath test. Ingest glucose (normally absorbed in SI)’ if bacteria overgrow then broken down to hydrogen and CO2 instead. Hydrogen exhaled and measured. Must not smoke before this.. Gold standard is culture of SI fluid.
Gold standard test for SIBO?
SI fluid aspiration
Investigations done during ascitic tap for undetermined cause of ascites?
Cell count, MC&S, cytology, protein and albumin, LDH, glucose, amylase
Key investigation for acute management of ascites?
Do paracentesis. If raised cell count consistent with SBP (>250cells/mm3) then give broad spectrum antibiotcs.
Management of ascites?
Firstline is spiro. Can use furosemide if refractory, or where potassium rises. If fails do therapeutic paracentesis
Features and presentation of scurvy?
Vitamin C deficiency. Relatively common in elderly and socially disadvantaged. Vit C needed to make collagen; deficiency means collagen not replaced and get these symptoms. Muscle and joint pain, fatigue, perifollicular haemorrhages, gingivitis, poor wound healing, easy bruising
Pellagra cause and features?
Vitamin B3 deficiency (niacin) Get diarrhoea, dermatitis and dementia. Treat with vitamin replacement.
Red cell distribution width and MCV?
High RDW and low MCV indicates IDA; normal RDW and low MCV indicates anaemia cause by chronic disease or thalassaemia
Cholestasis/ALP in AI liver disease?
Cholestasis dominant in PBC or PSC, less so in AIH.