Gastroenterology Flashcards
Main differentials for a GI bleed
Oesophagitis Peptic ulcer Varices/Portal hypertensive gastropathy Erosive duodenitis or gastritis Mallory-Weiss tear Malignancy Vascular malformations
Two commonly used scoring system for GI bleed
Rockall or Glasgow Blatchford
When should you give a patient blood?
Hg <70g/L (or has significant CVD)
Secondary prevention of varices?
Beta blockers
What is the post-endoscopy care for a patient with gastric bleeding?
PPI (omeprazole/lansoprazole)
H.pylori treatment
Re-endoscopy in 6-8 weeks as risk of rebleeding
When would you give IV PPI for a gastric bleed, and how long for?
If visible blood vessel or actively bleeding ulcer at time of endoscopy
72 hours of IV PPI
Immediate treatment of variceal bleed? When is it contraindicated?
2mg qds Terlipressin (vasoconstrictor)
+ IV abx if also liver disease (risk of bacteria from gut entering blood stream)
CI in peripheral vascular disease
Main causes of liver disease
Alcohol
NAFLD (insulin resistance leading to fat accumulation)
Viral hepatitis (A to E, EBV, CMV)
Drugs (paracetamol, idiosynchratic)
Immune (autoimmune hepatitis, primary biliary cholangitis/cirrhosis, sclerosing cholangitis)
Inherited (haemochromatosis, Wilson’s, alpha1 antitrypsin deficiency)
Vascular (Budd-Chiari, liver ischaemia)
Liver non-invasive screen
SCREENING QUESTIONS
Bloods:
LFTs, FBC, U&Es
Haematology:
Iron studies
Viral serology:
hep B surface antigen, hep C antibody, HIV
Immunology:
autoantibodies, Anti-mitochondrial, anti-nuclear, smooth muscle, Ig, COELIAC
Biochemistry:
iron studies, ferritin, copper studies, alpha1 antitrypsin, blood glucose
Young patients:
serum copper, caeruloplasmin
Imaging (US, CT/MRI, endoscopy)
Score to use to determine who should get liver transplant?
MELD score
What approach would you take in a patient with jaundice?
?Large duct obstruction (need imaging; hx of rigors or biliary pain)
?Severe liver injury (ill patient, high transaminases, coagulopathy, encephalopathy)
?Potential drug cause
?Another obvious cause (alcohol, viral hep, pregnancy, heart failure, cancer)
Fast-track non-invasive screen (hepatitis, CMV, EBV, auto-antibodies, Ig)
Liver biopsy
Ascites management
Fluid and salt restriction
Diuretics (SPIRONOLACTONE, furosemide as adjuvant, monitor weight)
Large-volume paracentesis
Transjugular intrahepatic porto-systemic shunt (TIPSS) - risk of encephalopathy (not possible if MELD >18, HF, pulmonary HTN)
Common changes in electrolytes in liver disease?
Hypo everything
What is iron deficiency anaemia a high risk sign of?
GI malignancy
Renal cancer
Therefore require both bi-directional endoscopy and urine dipstick/USS renal
First test to be done if iron deficiency anaemia?
Coeliac screen (tTg antibody)
What does a sigmoidoscopy look at?
Left side of large intestine (descending colon, sigmoid and rectum)
What are the possible tests to assess the colon?
Colonoscopy/flexible sigmoidoscopy
Virtual colonoscopy (CT pneumocolon) - radiation risk, may miss early cancers
CT with long oral prep (good for old and frail but can miss smaller cancers)
Colon capsule (research tool)
Definition of diarrhoea
Passage of 3 or more loose stools in 24 hours
Definition of dysentery
Presence of blood/mucus in stools
What are the four mechanisms of diarrhoea and examples of each
Osmotic (lactose intolerance, osmotic laxatives e.g. lactulose)
Malabsorption (pancreatic insufficiency, Crohn’s, Coeliac)
Motility (post vagotomy, IBS, carcinoid)
Secretory
Blood tests to investigate diarrhoea
FBC, CRP, thyroid function, coeliac serology
Investigations for acute presentation of suspected IBD
Bloods: FBC, CRP, U&Es, LFT
Stool culture and microscopy
Barium x-ray
Flexible sigmoidoscopy (colonoscopy dangerous to do if acute flare)
Treatment for severe first presentation of UC
ANTICOAGULATION (risk of DVT)
IV steroids (hydrocortisone or methylprednisolone)
Assess at day 3 (stool sample, CRP, albumin)
Continue if responding
IV infliximab or cyclosporine if no response
Surgery if no response
Coeliac testing
TTG antibodies and IgG (some patients are IgA deficient, and TTG ab is a type of IgA)
OGD and duodenal biopsy (villous atrophy)
Causes of lower GI bleeding (categorised)
Anatomical: diverticular disease (most common), haemorrhoids, anal fissures
Vascular: angiodysplasia; acute mesenteric ischaemia (ischaemic colitis)
Neoplasmic: polyps, colorectal carcinoma
Inflammatory: IBD, infective
Most common area for diverticuli
sigmoid
Diverticular disease diagnosis
Colonoscopy
CT cologram
Abdo CT with contrast (identify inflammation and abscesses)
Barium enema
Diverticular disease treatment
Increased dietary fibre intake
Mild attacks of diverticulitis with abx
Hinchey IV with faecal peritonitis will require surgical resection and stoma
Angiodysplasia pathophysiology and presentation
AVM usually in proximal colon
Episodic painless bleeding and usually self-limiting
What is Heyde’s syndrome
Angiodysplasia associated with aortic stenosis
Acute mesenteric ischaemia presentation
Severe pain out of proportion of clinical signs
Bleeding less common
Associated with AF –> emboli has migrated to bowel
Genetic conditions causing polyps
Familial adenomatous polyposis (FAP), Hereditary nonpolyposis colorectal cancer (HNPCC)
High risk of malignancy - surgical removal of polyps required
Where is mesenteric ischaemia most likely to occur?
Watershed areas such as splenic flexure in the at the borders of territories supplied by superior and inferior mesenteric artery
Infective causes of dysentery
E.coli, shigella, campylobacter entamoeba
Low volume bloody diarrhoea and abdo pain
E.coli 0157 presentation
HUS
Haemolytic anaemia
AKI
thrombocytopaenia
Investigations for lower GI bleeding
Bedside: BP, BM, faecal calprotectin, stool sample, ECG
Bloods: CROSS MATCH
Imaging: erect CXR for air under the diaphragm (perforation), CT/CTA to assess cause and site
Special: flexible sigmoidoscopy (younger patients), colonoscopy (malignancy), upper GI endoscopy, angiographic transaterial embolisation (control massive bleeding)
Management of massive lower GI bleeding
ABC resuscitation: two wide bore cannulae, IV saline, bloods (clotting, cross match), possible early blood transfusion, regular monitoring, involve seniors
Localisation: imaging and endoscopy (upper and lower)
Intervention: colonoscopy if stable, coagulation (vasoconstrictors or sclerosing agents), angiography (if colonoscopy is unsuccessful or CI)
When would you put a patient with occult bleeding on 2 week wait?
> 40 unexplained weight loss and abdominal pain
> 50 unexplained rectal bleeding
> 60 iron deficiency anaemia or change in bowel habit
Rectal/abdominal mass
<50 rectal bleeding and unexplained symptoms (e.g. weight loss, pain, anaemia)
Unexplained IDA in men or post-menopausal women
When should you stop iron tablets prior to endoscopic investigations?
7 days prior
What is the cell type characteristically seen in iron deficiency anaemia?
Inherited haemolytic anaemia?
IDA: pencil cells
Haemolytic: spherocytes
Management of HUS
IV fluids
Electrolyte correction
AKI management
Investigation to carry out should a cause of IDA not be found in LGI tract
Capsule endoscopy (small bowel)
Investigations and treatment for acute mesenteric ischaemia
Erect CXR (perforation and ‘thumbprinting’)
CTA and MRA
IV fluids, NG decompression, anticoagulation
Causes of upper GI bleeds (according to anatomical location)
Oesophagus: varices, malignancy, oesophagitis
Gastric: ULCERS, Mallory-Weiss tear, gastritis, malignancy
Duodenal: ulcers, diverticulae, aortoduodenal fistulae
Other: aspirin, NSAIDs
Dieluafoy’s lesion (abnormal diameter of blood vessels), Osler-Weber-Rendu Syndrome (epistaxis and GI bleeds), gastric antral vascular ectasia (watermelon stomach)
Initial investigation for upper GI bleed
Upper GI endoscopy immediately following resus if unstable (within 24 hours for others)
Why might urea be raised in a patient with UGI bleeding?
Digested blood
Hypovolaemic so renin system activated which causes reabsorption of salt, water and urea
Imaging in UGI bleed
Erect CXR: perforation (air under diaphragm)
USS/CT depending on aetiology
What scoring systems can you use for GI bleeding
Blatchford (initial assessment)
Rockall (pre and post endoscopy)
Treatment of non-variceal upper GI bleeding
Endoscopic: mechanical (e.g. clipping) +/- adrenaline; thermal coagulation + adrenaline
Medical: PPIs (should be post-scope if evidence of recent haemorrhage)
Treatment of variceal bleeding of upper GI bleeding
Endoscopic: band ligation
Medical: terlipressin (vasoconstricting and reduces portal pressure), prophylactic abx (risk of spontaneous bacterial peritonitis)
Student after night out presenting with vomiting with small amounts of blood following bouts of retching
Mallory-Weiss tear
How do NSAIDs cause GI bleeds
Inhibit COX-1
Increased production of prostaglandins –> increased histamine –> increased HCl production from parietal cells
Two types of oesophageal cancer and who is most likely to get them?
Squamous cell carcinoma (upper 2/3): smoker/alcohol
Adenocarcinoma (lower 2/3): hx of GORD leading to columnar metaplasia (Barret’s oesophagus)
Definition of chronic liver disease
Progressive liver dysfunction over >6 months
What are the complications of decompensated liver disease?
Coagulopathy (reduced clotting factor synthesis)
Jaundice (impaired bilirubin breakdown)
Ascites (poor albumin synthesis and increased portal pressure due to scarring)
Encephalopathy
GI bleeding (increased portal pressure leading to varices)
Score used for chronic liver disease and what factors does it consider?
Child-Pugh score
Albumin, INR, Bilirubin, encephalopathy, ascites
Class A-C
Which patients would you perform a liver biopsy in?
Liver disease with unknown cause
Differentiating between chronic and acute or fibrosis and cirrhosis
What vitamins and minerals are stored in the liver?
Vitamin D
B12 (nerve function and RBC production)
A (retina)
copper
iron
Breakdown product of RBC
Haem –> bilirubin –> conjugated in liver –> excreted in bile
What are kupffer cells used for?
Phagocytosis to fight infection and breakdown RBCs in the liver
Causes of acute hepatitis
Viral
alcohol
drugs
toxins
Types of cholestasis
Intrahepatic (inflammation within hepatocytes, PBC, drugs, pregnancy)
Extrahepatic: stones, carcinoma of head of pancreas, sclerosing cholangitis, portal hepatic LN metastases
What LFTS will be deranged cholestatic liver disease?
ELEVATION in ALP, GGT +/- bilirubin (if obstructed bile duct)
Causes of cirrhosis
Chronic alcohol excess
Persistent Hep B and C
Autoimmune
Inherited metabolic (haemochromatosis, A1AT deficiency, Wilson’s)
Deranged LFTs in cirrhosis
Synthetic function affected
Hypoalbuminaemia, prolonged PT
Where is AST found
Liver
Cardiac muscle
Skeletal muscle (elderly following fall will have raised AST)
How do you distinguish between raised AST in liver and skeletal muscle
Creatine Kinase
Is AST or ALT more specific?
ALT (mostly found in liver)