Gastroenterology Flashcards
What are mallory bodies?
Seen in injured hepatocytes (specifically alcohol hepatitis) and they show intracytoplasmic eosinophilic inclusions
Which embryonic structure do mallory bodies originate from?
Endoderm - this is where hepatocytes originate from
Risk factors for peptic ulcers
- S Smoking/Spicy foods
- H Helicobacter pylori/Hypercalcaemia
- A Aspirin/Alcohol
- Z Zollinger–Ellison syndrome
- A Acidity
- N Non-steroidal anti-inflammatory drug use (NSAID) use
What is the first line diuretic for treating ascites in cirrhosis?
Spirinolactone - aldosterone antagonist
Reduction of what mediator leads to oesophageal achalasia?
Nitric oxide - normally it increases smooth muscle relaxation and relaxes the tone of the lower oesophageal sphincter
What are the classical features of pellagra?
Diarrhoea, dermatitis and dementia
What are the three types of autoimmune hepatitis?
Type 1- Anti-nuclear antibodies (ANA) and/or anti-smooth muscle antibodies (SMA). Affects both adults and children
Type 2 - Anti-liver/kidney microsomal type 1 antibodies (LKM1). Affects children only
Type 3 - Soluble liver-kidney antigen. Affects adults in middle-age
What is the treatment for C. difficile infection?
First-line therapy: oral vancomycin for 10 days
Second-line therapy: oral fidaxomicin
Third-line therapy: oral vancomycin ± IV metronidazole
What is Peutz-Jegher’s syndrome?
Autosomal dominant condition with hamartomatous polyps in the gastrointestinal tract (mainly small bowel) –> small bowel obstruction is a common presenting complaint, often due to intussusception + gastrointestinal bleeding
There are also pigmented lesions on lips, oral mucosa, face, palms and soles
What type of diet is useful in IBS?
Fermentable Oligo-Di-Monosaccharides and Polyols (FODMAP) diet
What two blood tests are used to monitor haemochromatosis?
Ferritin and transferrin
Transferrin saturation should be kept below 50% and the serum ferritin concentration below 50 ug/L.
What sign can you see on imaging of pancreatic cancer?
Double duct sign - the presence of dilatation of both the pancreatic and common bile ducts
What is alcohol ketoacidosis?
The presence of acidosis, raised ketones and normal/low blood glucose. This occurs in chronic alcoholics following an episode of reduced intake of food.
Once the person becomes malnourished, after an alcohol binge the body can start to break down body fat, producing ketones.
Mx: Need to rehydrate with saline and give thiamine to prevent Wernicke’s encephalopathy
*If glucose is low, you should never replace it without providing thiamine first as glucose promotes metabolism, in which thiamine acts as a co-factor –> accelerates the depletion of thiamine and increases the risk of Wernicke’s.
How can you categorise ascites?
Based on serum-ascites albumin gradient (SAAG)
SAAG > 11g/L (indicates portal hypertension):
* cirrhosis/alcoholic liver disease
* acute liver failure
* liver metastases
* Cardiac: right heart failure, constrictive pericarditis
SAAG < 11g/L:
* Hypoalbuminaemia:nephrotic syndrome, severe malnutrition (e.g. Kwashiorkor)
* Malignancy: peritoneal carcinomatosis
* Infections: tuberculous peritonitis
Why should you avoid metoclopramide in bowel obstruction?
Despite metoclopramide having prokinetic properties where it stimulates peristalsis, in a complete bowel obstruction picture, stimulation of bowel movement can precipitate perforation
How does urea levels differ in an upper vs lower GI bleed?
Upper = raised
Lower = normal
The raised urea is caused by the large protein ‘meal’ of blood in the upper GI tract, which is digested.
What are the features of Budd Chiari Syndrome?
Triad of sudden onset abdominal pain, ascites, and tender hepatomegaly
It is usually caused by haemotological diseases and procoagulant conditions such as:
* polycythaemia rubra vera
* thrombophilia: activated protein C resistance, antithrombin III deficiency, protein C & S deficiencies
* pregnancy
* combined oral contraceptive pill: accounts for around 20% of cases
Whar scoring systems are used in upper GI bleeds?
Glasgow-Blatchford score at first assessment
* helps clinicians decide whether patient patients can be managed as outpatients or not
Rockall score is used after endoscopy
* provides a percentage risk of rebleeding and mortality
* includes age, features of shock, co-morbidities, aetiology of bleeding and endoscopic stigmata of recent haemorrhage
What is the acute treatment of variceal haemorrhage?
- ABC resusctitation + consider blood products
- Vasoactive drugs: terlipressin, octreotide
- Prophylactic IV Abx
- Endoscopy –> variceal band ligation
- Sengstaken-Blakemore tube if uncontrolled haemorrhage
- Transjugular Intrahepatic Portosystemic Shunt (TIPSS) where hepatic vein is connected to portal vein if above measures fail (however risks hepatic encephalopathy)
What is the prophylactic management of variceal haemorrhage?
Propanolol
Non-cardioselective beta-blockers will cause vasodilation in these engorged vessels and reduced heart rate which lowers the blood pressure in the variceal veins and reduces the risk of rupture.
What is the management of UC remission?
Aminosalicylate (oral or topical/rectal, or a combination of both)
If patients experience a severe relapse or >=2 exacerbations in the past year: consider oral azathioprine or oral mercaptopurine
*Methotrexate is not licensed for UC management unlike in Crohn’s
What causes achalasia and what are its features?
Failure of oesophageal peristalsis and of relaxation of the lower oesophageal sphincter (LOS) due to degenerative loss of ganglia from Auerbach’s plexus
Features:
* dysphagia of BOTH liquids and solids
* typically variation in severity of symptoms
* heartburn
* regurgitation of food
* may lead to cough, aspiration pneumonia etc
* malignant change in small number of patients
What investigations can you do in achalasia and what would the findings be?
Oesophageal manometry:
* excessive LOS tone which doesn’t relax on swallowing
* considered the most important diagnostic test
Barium swallow:
* shows grossly expanded oesophagus, fluid level
* ‘bird’s beak’ appearance
Chest x-ray:
* wide mediastinum
* fluid level
What is the first-line treatment of achalasia?
Pneumatic (balloon) dilation is increasingly the preferred first-line option
* less invasive and quicker recovery time than surgery
* patients should be a low surgical risk as surgery may be required if complications occur
If doesn’t work: Heller cardiomyotomy surgical intervention OR intra-sphincteric injection of botulinum toxin OR drug therapy (e.g. nitrates, calcium channel blockers)