Gastro difficult questions Flashcards
MTX induced hepatitis
Usually acute onset
High and prolonged doses
Where? When? How?
Approach to LFTs
Where?
Australia - elevated AST ?ishcaemic ?toxic
Asia - orofecal transmittable hepatitis virus
Northern European - homozygosity for C282Y mutation HFE gene (haemachromatosis)
When?
Medication related?
Younger - ?Wilson’s ?AIAT def
Older - comorbidities, ?drug induced liver injury, ?right heart failure
How?
Hepatocellular vs cholestatic
- AST and ALT highly concentrated in liver
- AST also in heart, skeletal muscle, kidney, brain and RBC
- ALT has low concentration in skeletal muscle and kidney
- ALT more specific for liver damage
- Half life ALT 47 hours; AST 17 hours
- Decrease in AST/ALT alone does not have prognostic meaning - monitor bilirubin and INR
Magnitude of enzyme alteration
Rate of change (increase/decrease over time)
ALT >1000 Think…
Think Ischaemic liver injury Viral liver injury Drug induced liver injiury Autoimmune hepatitis Choledocholithiasis
Mild alteration in aminotransferase levels…
History of ETOH/medication use
Risk factors for hepatitis –> hepatitis screen (hep B, C; if acute, hep A, E)
Increased trans sat and ferritin –> test for HFC mutation
Middle aged female +/- concomitant autoimmune disease –> ANA, ASMA, Anti-LKM
Consider also ceruloplasin level (wilson), A1At (esp if lower lobe emphysema), ttg ab (coeliac disease)
If all negative, think fatty liver
Cholestatic LFTs… think…
ALP
- Liver and bone diseases most common cause
- Also elevated in 3rd trimester of pregnancy and adolescence
- t1/2 - 1 week (rise late in bile duct obstruction and take a while to get better)
If suspecting hepatic source of ALP rise think…
Medications –> check bili and AST/ALT –> liver US (normal)
Female with other autoimmune disease –> check IgM, AMA –> liver US (diffuse disease) –> PBC
UC –> check ANCA, ERCP –> liver US (diffuse disease) –> PSC
RUQ pain, fever –> check bili –> liver (dilated bile ducts) –> biliary obstruction
Other malignancy? –> liver US –> hepatic mets
The primary factor leading to the accumulation in ascites in patients with chronic liver disease is
splanchnic vasodilation
Portal HTN when HVPG is
> =5mmgHg; clinically significant when >10-12mmHg
Leads to splanchnic vasodilation primarily led by nitric oxide
45M alcoholic
1st oesophageal variceal bleed –> endoscopic band ligation
How do you prevent recurrent bleeding?
Non-selective beta blockers (Carvedilol is the best) is superior to banding alone for grade 2-3 varices
How to classify oesophgeal varices?
Grade 1 - minimally elevated veins above service (can be flattened)
Grade 2 - medium sized low risk varices –> banded (do not flatten)
Grade 3 - takes up >1/3 of lumen, large varices, red spots over varices (high risk stigmata)
Grade 4 - fibrin plug (white plug) indicates high risk stigmata, Wale signs
New dx of UC
US - nil extrahepatic duct dilatation, nil gallstones
Abnormal LFTs bili 35 ALP 555 GGT 458 ALT 48 albumin 40
Next best investigation for abnormal LFTs?
UC is associated with primary sclerosing cholangitis (increases rate of colorectal ca - yearly colonoscopy even without UC)
90% PSC have UC
5% UC develops PSC
MRCP - gold standard
- Multifocal short annular strictures (beading)
Liver bx often not required
ERCP is not needed unless you want to dilate the strictures
What is PSC?
Autoimmune
Inflammation, fibrosis + stricturing of medium + large ducts –> cholestasis
Classic: intra + extra hepatic ducts
Small duct: normal cholangiography, but histo consistent
What bloods would you expect in PSC?
Cholestatic pattern
pANCA 65% positive
AMA PBC 90% positive (F>M)
IgG4 for AI pancreatitis
Azathioprine malignancy risks?
Skin cancer
Lymphoma especially in men
What’s the truelove and Witt’s criteria?
Motions/day Fever Rectal bleeding Resting pulse Hb ESR/CRP
Defines mild, moderate, severe UC
28F 2 year history of abdo pain and diarrhoea. Smokes 20 cigarettes a day. Small bowel series shows a long stricture in the terminal ileum.
In addition to pred, what is the best initial treatment?
Quit smoking (but this won't reduce the damage that is already done) Infliximab = more correct
What are some biologics used in CD?
Anti TNF: infliximab, adalimumab (CI in HF, malignancy)
Vedolizumab (anti-integrin inhibitor; very gut specific; stops migration of lymphocytes into the gut)
Ustekinumab (safest; suitable for older patients)
How do the treatment approaches differ between UC and CD?
UC - stepwise approach
CD - top down approach (treat aggressively)
What are some immunomodulators used in CD?
AZA +/- allopurinol
6MP
MTX
Whats Exclusive Enteral Nutrition (EEN) in CD?
Drink resource for 6 weeks = equivalent to steroids
Useful in those who can’t be immunosuppressed
When do you use abx in CD?
If confirmed infection only e.g. penetrating disease, perianal disease
What should we check before we start AZA?
TMPT mutation
What’s the use of allopurinol in azathioprine?
For those who shunt towards producing 6-MMP (inactive) (high TMPT activity). You put them towards the correct pathway and produce more 6-TGN (active).
Risk factors for CD recurrence
Smoking Genetics younger patients with more aggressive phenotype Disease duration ie shorter pre-op disease duration Disease extent - UGI, diffuse disease Prior surgery Penetrating or fistulating disease Stricturing disease
Monitor with scope + MRE
Therapies post resection for CD
High risk patients - immunosuppressive therapy
If low risk + treatment naive, can consider 3/12 metronidazole
But if they’ve needed surgery they’re going to be high risk of recurrence so in real life, everyone should be on immunosuppressants
58M iron deficiency anaemia requiring blood transfusion (despite oral iron supplements)
Normal gastroscopy and colonoscopy
BM exam normal
What’s the next best investigation?
Enteroscopy
- Capsule endoscopy
What’s the most common cause of small bowel bleed?
Angioplasia
If you suspect small bowel angioplasia, what next?
Double balloon enteroscopy - pass scope into the small bowel and use balloon to stop the bleeding
When do you use CT abdominal angiography and labelled red cell scan?
Acute bleed in CT angiography
Labelled red cell scan is done only when CT angiography is not available
25M episode of haematemesis. Nauseous, one large vomitus with fresh blood. No syncope or sizziness.
No past history of PUD
Smokes and heavy ETOH
Obs stable
Tender epigastric region
No melena on PR exam
What are the ddx and most likely dx?
Oesophageal varices
- Less likely given no mentioned history of cirrhosis
Gastric ulcer or duodenal ulcer
- Expect melena
- Shouldn’t get haematemesis in duodenal ulcer and haemodynamic instability
- Gastric ulcer should get coffee ground vomit and haemodynamic instability
- No risk factors
Mallory-Weiss tear***
- Probably most likely
- But no mention of repeated vomiting
H. pylori gastritis
- Unlikely
What’s King’s criteria for paracetamol OD?
Recommends who should be immediately referred for liver transplant
Arterial pH <7.3
INR >6.5 (PT >100s)
Creatinine >300micromol/L
Grade III or IV hepatic encephalopathy
- III: marked confusion, incoherent speech, sleeping most of the time but arousable to vocal stimuli
- IV: comatose, unresponsive to pain; decorticate or decerebrate posturing
Meet 2+ criteria = transfer for transplant
Other predictors of poor prognosis without transplant
Lactate >3.5mmol/L after fluid resus (<4h) or Lactate >3 mmol/L after full fluid resus (12h)
Phosphate >1.2mmol/L at 48-96h
Basic Autoimmune liver screen
Ana
Anti SM ab
IGG