Gastroenterology Flashcards
What are the side effects of Proton Pump Inhibitors (Omeprazole)?
Lack of acid = gastroenteritis (diarrhoea) + lack of B12
Can’t go in the sun (photosensitivity) as they have no hair (alopecia) so they get thin bones (osteoporosis)
and LFTs get higher…
What preparation should the patient undergo before a colonoscopy?
Few days before- low fibre diet, no seeds, nuts, raw fruit + veg
Day before- bowel prep meds, clear liquids (black tea and coffee)
On day- don’t eat or drink 2 hours beforehand
Who is eligible for the occult blood test screening?
60-69 year olds
Every 2 years
Commonest types of renal calculi?
Calcium oxalate 45%
Mixed calcium oxalate/phosphate 25%
Calcium phosphate 10%
Triple phosphate 10%
Urate 10%
Cystine 1%
Xanthine <1%
Staghorn calculi of ammonium magnesium phosphate or triple phosphate and are predisposed to form in the presence of which two bacteria
Ureaplasma urealyticum and Proteus infections
Urinary tract will be alkaline
What are the 3 common sites for berry aneurysms?
- Posterior communicating artery with the internal carotid (CN 3 affected)
- Anterior communicating artery with the anterior cerebral
- Bifurcation of middle cerebral a
3 medical conditions associated with berry aneurysms?
- Polycystic kidneys
- Coarctation of the aorta
- Ehlers Danlos
Patient has a thunderclap headache, what test should you do.
If negative what is the next test to perform?
- CT
- Lumbar puncture 12 hours after onset (if no CI)CSF is xanthochromic from Hb breakdown
What medication can you give to patients with SAH to reduce vasospasm?
Nimodipine IV- calcium antagonist = less ischaemia
Ultimately need to refer for neurosurgery- endovascular coiling or surgical clipping
Name of the radiology sign where bowel is trapped between the liver and diaphragm (mimics bowel obstruction)
Chilaiditi sign
How is hyperacute, acute and subacute fulminant liver failure defined?
Hyperacute= encephalopathy within 7 days of jaundice Acute= within 8 to 28 days Subacute= within 5 to 26 weeks
Which viruses can cause liver failure?
Hep B, Hep C + CMV
Signs of acute (fulminant) liver failure:
- Jaundice
- Hepatic encephalopathy
- Asterixis
- Constructional apraxia (can’t copy a 5 pointed star)
- Fetor hepaticus
Blood tests for a patient with fulminant liver failure:
Encephalopathy + jaundice + asterixis
FBC- neutrophilia may be EtoH or infection, GI bleed?
U+Es- may be giving laxatives as Rx so need baseline
LFTs- liver failure
Clotting- high PT and INR
Glucose- hypoglycaemic
Pregnancy test- HELLP
Paracetamol level, serology (hepatitis, EBV, CMV),
Ferritin, a1-antitrypsin, caeruloplasmin (low), autoantibodies
Rx of encephalopathy:
Excess ammonia
Lactulose TDS
Enemas (reduce numbers of nitrogen forming-bacteria)
Abx to reduce bacteria- metronidazole, rifaximin
Drug causes of jaundice split by pre-hepatic, hepatic and obstructive causes:
Pre-hepatic: anti-malarials can cause haemolysis (+ dapsone given for dermatitis herpetiformis)
Hepatic: TB drugs- isoniazid, pyrazinamide, rifampicin; paracetamol
Obstructive- PPPCOS:
Penicillin, Prochlorperazine (anti-D2 R), Pill
CO-amoxiclav,
Sulfonylureas (gliclazide)
What level of bilirubin produces visible jaundice?
> 60umol/L
What form of bilirubin is insoluble?
Unconjugated bilirubin, when it has been broken down from globin of haemaglobin.
Causes of unconjugated bilirubinaemia
Overproduction- haemolysis, ineffective erythropoeitin
Impaired hepatic uptake- drugs (rifampicin), right heart failure
Impaired conjugation- Gilbert’s, Creigler Najjar (neonates, total lack)
Neonatal jaundice
Causes of conjugated hyperbilirubinaemia
Hepatocellular dysfunction: hepatocyte damage ± cholestasis
Impaired hepatic excretion
Causes of jaundice in a previously stable patient with cirrhosis:
Sepsis, constipation Malignancy- HCC Drugs, Alcohol GI bleeding Interventions
King’s criteria for paracetamol induced overdose:
PParaCE
pH < 7.3 when it’s 24 hours after ingestion
Or all 3 of:
PT >100s
Creatinine >300umol/L
Encephalopathy- grade 3 (asterixis, incoherent) or grade 4 (coma)
King’s non-paracetamol liver failure:
PT > 100s
Or 3 of:
Age <10 years or >40 years
Bilirubin >300
Clotting- PT >50
Drug induced liver failure (not paracetamol)
Encephalopathy onsetting 1 week after onset of jaundice
What drugs caused your chronic liver failure MAM?
Methotrexate (lung fibrosis, bone marrow suppression)
Amiodarone (slate grey skin, thyroid, lung fibrosis, peripheral neuropathy)
Methyldopa
What do routine bloods can tell you in a patient who has chronic liver disease?
FBC- macrocytic anaemia (EToH), normocytic (variceal bleed)
Clotting, albumin, PT+INR- synthetic function
Ammonia level- in suspected encephalopathy
U+Es- hepatorenal syndrome (urea produced by liver so caution in interpretation)
Child Pugh Score for grading of cirrhosis and risk of variceal bleeding?
ABCDE
Values for max score shown Albumin <28 Bilirubin >51 Clotting >6 Distension ascites moderate Encephalopathy 3-4
Common organisms causing spontaneous bacterial peritonitis + Rx:
E Coli, Klebsiella (G -ve), Streps
Broad sprectrum: Tazocin + cephalosporin
Drug induced lupus:
Hydralazine
Isoniazid
Procainamine/ Penicillinamine / Phenytoin
Why is Cregler Najjer syndrome so much more severe than Gilbert’s?
(Cregler causes neonatal jaundice with kernicterus)
Unlike Gilbert’s, where there is low activity of the enzymes conjugating bilirubin, in Crigler-Najjer’s there is virtually absent enzyme activity
(In uridine diphosphate glucuronosyltransferase enzyme)
What is Mirrizi’s syndrome?
Obstructive jaundice caused by compression of the common bile duct due to gallstone impaction in the cystic duct- associated with cholangitis)
Teenager with repeated jaundice, diagnosed with Dubin Johnson syndrome- what is this?
Like many of the inherited liver diseases it has autosomal recessive inheritance (as it’s due to abnormal protein activity so other gene can compensate)
Defective hepatocyte excretion of conjugated bilirubin into bile canaliculi.
Liver biopsy diagnoses, no Rx needed
Bloods to do in a patient with pre-hepatic jaundice:
FBC- haemolytic anaemia Clotting Blood film- schistocytes (fragmented RBCs), parasites Reticulocyte count Coombs- autoimmune Haptoglobulins- bind free Hb Monospot tes- EBV IgM
U+E, LFTs, Albumin, Paracetamol levels
Blood cultures, serology
What width of bile dile implies dilation?
What IHx is warranted if seen on USS?
> 6mm suggests obstruction
ERCP if dilated and LFTs not improving
Imaging recommended in a jaundiced patient where obstructive jaundice is suspected?
What is next line if bile ducts look normal?
USS- look for dilated bile ducts or stones
ERCP- if dilated + LFTs not improving
MRCP- if no stone is found but can see stones in gallbladder
Liver biopsy- if bile ducts are normal
Name some features of the different stages of encephalopathy:
Stage 1: sleep-wake reversal, constructional apraxia (5pt star)
Stage 2: confused, behaviour change ± liver flap
Stage 3: incoherent, restless
Stage 4: coma
What are the 3 features of hepatorenal syndrome?
Cirrhosis
Ascites
Renal failure
(This car is driving nowhere good)
Pathophysiology of hepato-renal syndrome?
- Portal hypertension initially (may lead to circulating vasodilator increase + NO release +bacterial migration + angiogenesis)
- Arteries in the splanchnic and systemical system dilate.
- As vascular resistance drops, baroreceptors activate angiotensin system, ADH (vasopressin activation) and sympathetic activation.
- Sympathetic output causes vasoconstriction of kidney
Rx of different types of hepatorenal syndrome?
Cirrhosis + ascites + renal failure (if other causes of renal failure like vasculitis and glomerulonephritis have been excluded)
Type 1- worse, rapidly progressing > Terlipressin reduces hypovolaemia (counters all the ADH around)
Median survival 2 weeks
Type 2- steady deterioration, transjugular intrahepatic portosystemic stent shunting (TIPS) to reduce pressure and portal hypertension
Difference between King’s criteria and Child-Pugh grading of cirrhosis:
King’s predicts outcomes of acute liver failure, so included variables are: age, bilirubin, clotting (PT), drug-induced, encephalopathy >1 week post-jaundice
Child-Pugh is for chronic liver failure, variables relate to long-term prognosis:
Albumin, Bilirubin, Clotting (PT), Distension- acites, encephalopathy
How is spontaneous bacterial peritonitis confirmed?
> 250/mm3 neutrophils in ascitic tap
What screening tests can be used for patients with cirrhosis to look out for hepatocellular carcinoma?
3 monthly USS ± AFP
Rx for pruritis in cirrhosis?
Cholestyramine (binds bile acids in the gut to reduce recycling of them and uptake)
Once in the gut 3 things happen to conjugated bilirubin
- Uptaken into the circulation (recycled)
- Converted to urobilinogen, reabsorbed and excreted in urine
- As urobilinogen, converted to stercobilinogen and remains in gut
Management of ascites in cirrhosis?
Similar to heart failure:
Fluid restrict 1.5L
Low salt diet
Spironolactone (acts on angiotensin axis) ± furosemide
Daily weights
Parencentis with concomitant albumin infusion
Aside from hepatorenal syndrome what other causes of deteriorating renal function may be linked to the patient’s cirrhosis?
Reduce clearance of immune complexes by the liver may lead to more lodging in the kidney > IgA nephropathy or glomerulosclerosis
Hep C- membranoproliferative GN (mesangiocapillary GN)
Hep B-membranous nephropathy (baby in membrane, mum is so shocked she gets goosebumps which are nodular hence polyarteritis nodosum associated)
a1-antitrypsin- membranoproliferative GN
Which ethnicity is at risk of hereditary haemochromatosis?
Celtic- northern europe ancestry
Genetic inheritance of haemochromotosis:
Autosomal recessive (like most liver pathologies)
Chromosome 6- HFE gene
Increased iron reabsorption in the gut
Features of haemochromatosis:
Relate to where iron is deposited
DM (pancreas), hypogonadism (pituitary)
Hepatomegaly/cirrhosis, dilated cardiomyopathy, slate-grey skin, osteoporosis
Arthralgia (joints)
Tests in a patient with bronze diabetes:
Bloods: high ferritin (iron stores) + transferrin saturation (carrier)
Raised LFTs, HbA1c (DM)
Liver MRI: iron overload
Liver biopsy: Perl’s stain quantifies iron loading and severity
Echo: check for cardiomyopathy
Rx for haemochromatosis:
1st. Venesection: a unit a week until ferritin <50ug/L, then 2 monthly
2nd. Desferrioxamine: binds free iron in blood and increases excretion
Check for diabetes
Relative screening
What is the pathophysiology of a1-antitrypsin deficiency?
A1-antitrypsin is a serine protease inhibitor that dampens down inflammatory cascades
In lung it prevents tissue damage from neutrophilic elastase enzymes.
Without it patients are at risk of emphysema, cirrhosis and hepatocellular carcinoma Chromosome 14 (autosomal recessive)
How are the different types of a1-antitrypsin distinguished genetically?
Can’t measure a1 enzyme levels as it is an acute phase protein
Mobility electrophoresis: If medium (PiMM) then enzyme is normal If slow (s) or very slow (z), patient is heterozygotic (PiMZ or PiSZ) then unlikely to be affected
Only if two very slow forms (zz aka PiZZ) is the patient affected
Patient has been getting breathless and jaundiced, with xray showing emphysematous pattern. How is a1-antitrypsin investigated?
Electrophoresis of a1-antitrypsin (PiZZ forms, very slow)
Serum a1-antitrypsin levels (but is an acute phase reactant)
Liver biopsy: Periodic acid Schiff +ve
How does y-glutamyltransferase (y-GT) help distinguish the cause of raised alk phos?
Y-GT produced by liver, pancreas, kidney + intestine but not bone
So if Alk Phos is raised but y-GT is not it is more likely to be bone turnover
However alk phos is produced by kidney and intestine too so if both raised, it could be most of the abdominal organs
If AST: ALT ratio is more than 2, what cause of hepatocellular injury is likely?
Alcoholic liver disease
May also have a high y-GT, macrocytosis and normal alk phos
Gold standard to identify cause of chronic liver disease?
Liver biopsy- tells definitively
Biopsy shows liver granulomas, what could be differential for this finding?
Primary biliary cirrhosis Sarcoid, PAN, SLE, Wegener's TB, syphilis, HIV + toxoplasmosis/CMV/mycobacteria Isoniazid, carbemazepine, allopurinol Lymphoma
How is Primary Biliary Cirrhosis typically found?
Incidental finding of raised alk phos on routine LFTs in 50s
- asymptomatic
- progresses to cirrhosis
How is PBC diagnosed?
Often find raised alk phos in asymptomatic patient
Anti-mitochondrial Abs
(Anti-Mi2 is most specific)
Raised IgM
USS: shows no extrahepatic cholestasis cause
Generally biopsy not required
Rx of primary biliary cirrhosis:
Fat-soluble vitamins (ADEK- as absorption is low with cholestasis)
Ursodeoxycholic acid- protects hepatocytes from bile-acid apoptosis
How does primary sclerosing cholangitis differ from primary biliary cirrhosis in the part of the liver affected?
PBC- granulomatous inflammation of interlobular bile ducts, more benign, anti-mitochondrial Ab
PSC- extrahepatic ducts which may cause PBC secondarily, UC associated, more aggressive + likely to get cancer of colon/gallbladder/liver, ANCA or Smooth muscle Ab
What imaging will distinguish PBC from PSC typically?
ERCP demonstrates extrahepatic bile duct involvement/fibrosis as well as intrahepatic (strictures + beading of bile duct), whereas in PBC intralobular small bile ducts are affected.
PSC can cause PBC
Patient has epigastric pain, jaundice fever and an itchy rash of raised red wheals.
On examination you note swollen tender finger joints. Can’t find any evidence of alcoholic, fatty or hepatic cause. What may be the cause?
Autoimmune hepatitis, associated with other autoimmune conditions:
Type 1 DM, thyroiditis, coeliac disease, RA
What autoantibodies are associated with different types of autoimmune hepatitis?
Type 1: responds to immunosupression, 80% smooth-muscle Abs, 10% anti-nuclear Ab, raised IgG
Type 2: presents in children, less treatable, anti-liver kidney microsomal type 1 abs (LKM1 +ve), smooth muscle -ve
Type 3: soluble liver antigen Abs, or liver-pancreas antigen Abs
Rx of autoimmune hepatitis
Immunosupression: prednisolone, azathioprine
Like all cirrhosis: liver transplant
What is the difference between steatosis and steatohepatitis?
Both may occur in NASH
Steatosis- increased fat in hepatocytes (may occur in alcoholism Wilson’s)
Steatohepatitis- inflammation also
Name the chromosomes involved in:
- Haemochromatosis
- A1-antitrypsin
- Wilson’s
- 6- HFE
- 14
- 13
Pathophysiology of Wilson’s disease?
Absorption of copper is normal but conjugation with caeruloplasmin for transport and excretion into bile is impaired- defective copper transporting ATPase is cause.
Therefore low caeruloplasmin
24 hour copper excretion is high (overflows but not enough)
Neuropsych symptoms of Wilson’s disease:
Medulla deposition- dysarthria, dysphagia
Basal ganglia- dyskinesias, dystonias, tremor, parkinsonism, micrographia, calculations
Cerebellar- ataxia, clumsiness
Frontal- dementia, reduced memory + IQ, irritable
Psych- depression, mania, labile emotions, libido change, delusions
Tests to check in a 20 year old patient with arthralgia, raised LFTs, tremor, dysarthria, who you suspect Wilson’s:
Urine- 24 hr copper (raised as it overflows)
Bloods- serum caeruloplasmin (low), serum copper (low), LFTs
Gene testing- chromosome 13
Liver biopsy
Slit lamp- Kayser Fleischer rings
MRI head- degeneration of basal ganglia, fronto-temporal, cerebellar, brainstem