Gastroenterology Flashcards
What are the two main characteristic features of acute upper GI bleed?
Haematemesis and/or malaena
Give 2 groups of patients with higher prevalence of UGIB.
Men, low SES, elderly
What are the two most common causes of UGIB?
Ulcer bleeds and variceal bleeds.
Name 3 risk factors for an UGIB?
NSAIDs, aspirin, anticoagulants, H. pylori
What are the two assessment tools for risk stratification in UGIB advocated by NICE? At what point should each be used?
Glasgow-Blatchford score at first assessment, then the full Rockall score following endoscopy.
What does the Glasgow-Blatchford score predict more accurately than the Rockall score?
An individual’s need for intervention and transfusion. Both score similarly on predicting mortality.
In an UGIB, what management significantly reduces mortality
Early, intensive resuscitation
How should haemodynamic stability be acheived in UGIB?
Use of IV crystalloid/colloid, blood transfusion, O2 therapy, correction of coagulopathy
What strategy of blood transfusion is used in UGIB and why?
Restricted blood transfusion therapy (e.g. Hb of 70-90g/L), associated with better 6 week survival and reduced risk of rebleeding
If there is a high suspicion of variceal bleeding in an UGIB (e.g. liver cirrhosis, signs of liver disease, previous variceal bleeding) what two drugs should you give?
IV terlipressin.
Prophylactic broad spectrum Abx due to increased risk of bacterial infection.
What investigation is used to diagnose the cause of UGIB and give prognostic details?
Endoscopy
When should endoscopy occur following an UGIB in:
a) a haemodynamically stable patient
b) an unstable patient
a) Within 24 hours of admission
b) Immediately following resuscitation
What are 2 intervention options for non-variceal UGIB?
1) mechanical method (e.g. clips) with adrenaline
2) thermal coagulation with adrenaline
3) injection of thrombin with adrenaline
If interventional endoscopic techniques don’t stop bleeding in non-variceal UGIB, what should be considered?
Interventional radiology or surgery
What is the first line treatment for oesophageal varices?
Endoscopic band ligation
First line treatment for gastric varices?
Endoscopic intravariceal injection of cyanoacrylate tissue glue
What should be considered for oesophageal varices if band ligation doesn’t work?
TIPS- transjugular intrahepatic portosystemic shunt
What therapy should be used following haemostasis in high risk UGIB patients? Give length of treatment and route of administration.
72 hours IV PPI
What should you do if a patient is on aspirin with an UGIB?
Acutely- withhold until haemostasis acheived, then restart within 7 days (ideally 1-3 days after)
What should you do if a patient is on an NSAID with an UGIB?
Acutely= stop NSAID. Review need for NSAID. If still needed, restart COX-2 selective NSAID (e.g. celecoxib) at lowest dose with PPI.
What is the first step in diagnosis of coeliac disease?
Tissue transglutaminase antibodies + immunoglobulins (total IgA)
Why do you have to measure immunoglobulins alongside TTG antibodies for the diagnosis of coeliac disease?
Because 2-5% of patients are IgA deficient, and TTG antibodies are mostly IgA. So may get a false negative result if you just measure TTG Abs
What is second line serological testing option for coeliac disease?
IgA Anti-endomysial and IgG anti-gliadin antibodies.
What is the gold standard investigation for diagnosis of coeliac disease? What should patients be instructed to do prior to this investigation.
OGD and duodenal biopsy. Patients advised to continue gluten-rich diet for at least 6 weeks prior to testing.
What are the 3 classical histological findings of coeliac disease?
Subtotal villous atrophy
Crypt hyperplasia
Lymphocytic infiltration of lamina propria
Those with coeliac disease should avoid foods containing what three ingredients?
Wheat, rye, barley
What monitoring do patients with coeliac disease require?
Annual BMI monitoring
Annual review to assess diet adherence, symptom control, need for further investigations (e.g. DXA scan)
What is the first line treatment of prevention of variceal bleeding?
Non-cardioselective beta-blockers e.g. propranolol, carvedilol, labetalol.
What is the most common reason for iron deficiency anaemia in post-menopausal women and adult men?
Blood loss from the GI tract
What is the cell morphology in iron deficient anaemia?
Hypochromic, microcytic
Name 2 other types of anaemia that are microcytic hypochromic other than IDA.
Thalassaemia, sideroblastic anaemia, some anaemias of chronic disease
What is the most powerful test for iron deficiency?
Serum ferritin
Say whether the following markers would be high or low in IDA;
- ferritin
- transferrin saturation
- TIBC
- red cell zinc protoporphyrin
- serum transferrin receptor
- low
- low
- high
- high
- high
When taking a history for IDA, what counts as a significant family history of colorectal cancer?
One affected first degree relative <50, or two affected first degree relatives
All patients with IDA should be screened for?
Coeliac disease (with serology)
In postmenopausal women and adult men with confirmed IDA, what further investigations would you do?
When would you not investigate further in these groups?
Upper and lower GI imaging e.g. OGD and colonoscopy.
You wouldn’t investigate further if there is a history of significant overt non-GI blood loss.
What is the treatment to correct iron deficiency? Give drug, dose, route, and length of treatment.
Ferrous sulfate 200mg 2-3 times daily PO, continued for 3 months after the iron deficiency is corrected.
What is second line treatment for iron deficiency if a patient can’t tolerate PO ferrous sulfate?
IV infusions e.g. iron sucrose or ferric carboxymaltose.
When are blood transfusions indicated in the treatment of IDA?
If a patient has symptomatic anaemia even following iron therapy, or if they are at risk of cardiovascular instability as a result of their anaemia
Iron deficiency occurs in 5-12% of otherwise healthy premenopausal women. Give 3 causes.
Menstruation, increased demands in pregnancy and breastfeeding, dietary insufficiency.
Give 3 situations where a premenopausal woman should be further investigated for IDA.
What investigation should they all receive?
- All should have coeliac screen
- OGD for women with IDA and upper GI symptoms
- Colonoscopy if colonic symptoms, strong FH of colon cancer, persistent IDA after iron therapy and treatment of causes
- Premenopausal women with IDA but without menstruation (hysterectomy, contraceptives)
How is GI bleeding investigated if colonoscopy is contraindicated?
CT colonography
What prep is needed for a CT colonography
Bowel prep 2 days before= laxatives and drinking clear fluids (including water, black tea and coffee, clear soup)
Is H. pylori gram negative or gram positive?
Gram negative
What does H pylori produce that allows it to survive in low pH conditions?
Urease
How does H pylori increase risk of gastric and duodenal ulceration?
Stimulates gastrin production and inhibits somatostatin production, resulting in increase in acid secretion
Give 2 ways of testing for H pylori.
Carbon-13 urea breath test
Stool antigen testing
Lab-based serological testing
What medication must be stopped prior to breath testing for H pylori and why?
PPIs stopped 2 weeks prior, as may result in false positive breath tests.
How is H pylori eradicated?
7 day course of triple therapy:
High dose PPI with 2 twice-daily antibiotics
What is the typical triple therapy regime for H pylori eradication?
High-dose PPI (e.g. lansoprazole 30mg) + amoxicillin + clarithromycin/metronidazole
How long following triple therapy is retesting to check for eradication of H pylori and what is the method?
6-8 weeks with carbon-13 urea breath test
Which of the forms of IBD is more common?
UC
Ulcerative colitis frequently presents with what clinical feature? Give 2 other abdominal clinical features.
Bloody diarrhoea
Colicky abdominal pain, tenesmus, may have constipation and/or fresh PR bleeding if localised rectal disease
Give 5 investigations for suspected UC in primary care and the likely results.
What result is an important marker of severity?
FBC- low Hb, raised WCC, raised platelets
CRP/ESR- raised
LFTs- low albumin (important marker of severity)
U&Es- electrolyte disturbance, signs of dehydration?
TFTs- rule out hyperthyroidism
Serum ferritin, vit B12/folate, vit D- may be low with malabsorption
Faecal calprotectin- raised with inflammation, normal in IBS
Coeliac serology- rule out coeliac disease
Stool MC&S (including Clostridium dificile)- to rule out infective cause
What radiological imaging is indicated to assess presence of complications of UC?
AXR +/- erect CXR
What is regarded as the best modality to diagnose UC and assess disease severity and extent?
Full ileocolonoscopy with 2 biopsies at a minimum of 5 sites.
When is colonoscopy contraindicated in IBD and what is used instead to confirm the diagnosis?
Contraindicated in acute colitis due to association with a high risk of perforation. Flexible sigmoidoscopy performed instead to confirm the diagnosis.
Macroscopic features of UC, true or false:
- Continuous
- Only ever affects up to the ascending colon
- Strictures
- True
- False, may occasionally affect the terminal ileum = backwash ileitis
- False, strictures very rare in UC (although do occur)
Give 3 microscopic features of UC
Confined to the mucosa
Crypt abscesses common
Goblet cell dysplasia common
Rarely granuloma formation
True/false: fistula formation occurs in UC.
False- the inflammation is confined to the mucosa so fistula formation doesn’t occur (unlike in Crohn’s)
Outline the management of inducing remission in severe UC.
- Urgent hospital admission
- IV corticosteroids (or cyclosporin if steroids CI)
- VTE prophylaxis (pts are prothrombotic)
- Add IV cyclosporin if unresponsive to steroids after 72 hours
- Consider urgent surgery- if acute complications of failure to respond to medical therapy.
What are first line agents for inducing remission of UC in mild/moderate disease?
Aminosalicylates e.g. mesalazine
In patients with distal disease, what form of aminosalicylates might be useful to use?
Topical e.g. suppositories or enemas
What is used to induce remission of mild/mod UC if aminosalicylates are CI (or as an add-on if no improvement after 4 weeks)?
PO corticosteroids
If there is no adequate response to Aminosalicylates or corticosteroids, what may be added to induce remission in mild/mod UC?
Tacrolimus
What type of drug is tacrolimus?
Calcineurin inhibitor
What class of drugs may be used to induce remission in UC if conventional therapies haven’t worked?
Biologic agents e.g. infliximab
What criteria are useful in evaluating the severity of an acute exacerbation of UC?
Truelove and Witts