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)
What is required before performing a large-volume paracentesis for ascites treatment?
Albumin cover with IV human albumin solution (HAS) to avoid paracentesis-induced circulatory dysfunction (PICD). PICD leads to faster accumulation of ascites, hyponatraemia, and renal impairment.
It can affect as many as 80% of patients who have large-volume paracentesis without any additional therapeutic management (with volume expanders such as HAS).
What is the first-line medication for constipation in IBS?
Bulk-forming laxative such as isphagula husk
You should avoid lactulose.
If constipation is not not responding to conventional laxatives, consider linaclotide
What PPIs are not advised for someone taking clopidogrel?
Omeprazole and esomeprazole: they decrease the efficacy of clopidogrel due to its inhibition of the CYP2C19 enzyme, which is needed to convert clopidogrel into its active metabolite
Consider lansoprazole instead which does not exhibit these effects
What is the best measure of acute liver failure?
INR/prothrombin time is better than albumin as it has a lower half-life.
These two measures are better than the other conventional “liver function tests” such as ALT, AST.
What pH and electrolye imbalance would be seen in prolonged vomiting?
Hypokalaemic, hypochloraemic metabolic alkalosis
Large amounts of hydrochloric acid are lost, causing loss of H+ ions, along with fluid loss. This leads to activation of RAAS due to reduced renal perfusion leading to increased aldosterone secretion. Aldosterone promotes the reabsorption of Na+ in exchange for H+ and K+ in the distal convoluted tubules of the kidneys. In general, where Na+ goes, water follows, meaning the blood volume is increased, however, more potassium and H+ are lost, leading to hypokalaemic metabolic alkalosis.
What is the management of haemochromatosis?
Regular venesection to keep transferrin saturation below 50% and serum ferritin concentration below 50 ug/l.
2nd line: desferrioxamine
Which tuberculosis medication has a side effect of peripheral neuropathy (B6 deficiency)?
Isoniazid
What are consequences of B6 deficiency?
Peripheral neuropathy
Sideroblastic anemia
What is carcinoid syndrome?
Group of slow-growing neuroendocrine tumours that release serotonin into the systemic circulation.
Usually occurs when metastases are present in the liver and release serotonin into the systemic circulation. May also occur with lung carcinoid as mediators are not ‘cleared’ by the liver
What are the features of carcinoid syndrome?
- flushing (often the earliest symptom)
- diarrhoea
- bronchospasm
- hypotension
- right heart valvular stenosis (left heart can be affected in bronchial carcinoid) - pulmonary stenosis & tricuspid regurgitation
- other molecules such as ACTH and GHRH may also be secreted resulting in, for example, Cushing’s syndrome
- pellagra can rarely develop as dietary tryptophan is diverted to serotonin by the tumour
What are the investigations and management options in carcinoid syndrome?
Investigation:
* urinary 5-HIAA
* plasma chromogranin A y
Management:
* somatostatin analogues e.g. octreotide
* diarrhoea: cyproheptadine may help
What is a Sister Mary Joseph nodule?
It is a sign of metastasis to periumbilical lymph nodes, classically from gastric cancer primary
What is the management of 1st episode C. diff infection?
- First-line therapy is oral vancomycin for 10 days
- Second-line therapy: oral fidaxomicin
- Third-line therapy: oral vancomycin ± IV metronidazole
What is the management of recurrent episode C. diff infection?
- Within 12 weeks of symptom resolution: oral fidaxomicin
- After 12 weeks of symptom resolution: oral vancomycin OR fidaxomicin
What is the management of life-threatening C. diff infection?
Oral vancomycin + IV metronidazole
What are predisposing factors that can cause bowel ischaemia (acute mesenteric ischaemia, chronic mesenteric ischaemia, ischaemic colitis)?
- increasing age
- atrial fibrillation - particularly for mesenteric ischaemia
- other causes of emboli: endocarditis, malignancy
- cardiovascular disease risk factors: smoking, hypertension, diabetes
- cocaine: ischaemic colitis is sometimes seen in young patients following cocaine use
What is the guidance for men and women for alcohol consumption?
Men and women should drink no more than 14 units of alcohol per week
If you do drink as much as 14 units per week, it is best to spread this evenly over 3 days or more
What is Plummer-Vinson syndrome?
Triad of iron deficiency anaemia, atrophic glossitis and oesophageal webs or strictures. Oesophageal webs are mostly located in the upper oesophagus and consist of multiple concentric narrowings.
What is the most common oesophageal cancer?
Adenocarcinoma
How do adenocarcinomas and squamous cell carcinomas in the oesophagus differ?
Adeno:
* Most common type in the UK/US
* Lower 1/3 of oesophagus
* Associated with GORD, Barrett’s, smoking, obesity
SCC:
* Most common in world
* Upper 2/3 of oesophagus
* Associated with smoking, alcohol, achalasia, Plummer-Vinson syndrome, diets rich in nitrosamines
What is the management of non-variceal bleeding (i.e. ulcers)?
Endocsocpy
Do not prescribe PPI before endoscopy. Can be prescribed to patients post-endoscopy if there is evidence of recent non-variceal haemorrhage.
What is the management of first-presentation dyspepsia?
Offer one of the following strategies depending on clinical judgement:
* Prescribe a full-dose PPI for 1 month
* Test for Helicobacter pylori infection if the person’s status is not known or uncertain. If positive, prescribe first-line eradication therapy.
If symptoms persist or recur following initial management, switch to the alternative strategy (for example, offer a full-dose PPI for 1 month if the person has been tested for H. pylori infection and vice versa).
What scoring system is used to assess the severity of liver cirrhosis?
Child-Pugh classification
In which conditions can you see apple core lesions on CT imaging?
Colorectal carcinoma
What should be given to patients before an endoscopy for suspected variceal bleed?
Terlipressin (potent vasoconstrictor, which increases systemic vascular resistance, reduces cardiac output and reduces portal pressure by about 20%)
Antibiotics (reduce the rate of bacterial infection, treatment failure, rebleeding and mortality)
What do the following hepatitis B results suggest?
anti-HBs positive, all others negative
anti-HBc positive, HBsAg negative
anti-HBc positive, HBsAg positive
anti-HBs positive, all others negative: previous immunisation
anti-HBc positive, HBsAg negative: previous infection (>6months), not a carrier
anti-HBc positive, HBsAg positive: previous infection, now a carrier
What are adverse effects of PPIs?
- hyponatraemia, hypomagnasaemia
- osteoporosis → increased risk of fractures
- microscopic colitis
- increased risk of C. difficile infections
What is the medical management of Wilson’s disease?
Penicillamine (chelates copper)
Tridentine hydrochloride is also becoming more popular.
What is the first-line pharmacological treatment of the following IBS symptoms?
Pain
Consipation
Diarrhoea
Pain: antispasmodic agents
Constipation: laxatives but avoid lactulose
Diarrhoea: loperamide
What route of aminosalicylate administration is preferred in mild/moderate flare up of distal UC (proctitis or proctosigmoiditis)?
Topical (rectal) suppositories of aminosalicylates
How does dysphagia present differently in oesophageal malignancy and achalasia?
Oesophageal malignancy: dysphagia symptoms initially with solids and then progressively moving onto liquids (progressive)
Achalasia: inability to swallow both liquids and solids from onset
What diet do suspected coeliac patients need to be on prior to serology testing and biopsy?
Patients need to be on gluten-containing diet for 6 weeks prior to serology testing and biopsy.
What is the management of primary biliary cirrhosis?
First-line: ursodeoxycholic acid (slows disease progression and improves symptoms)
Pruritis: cholestyramine
Fat-soluble vitamin supplementation
Liver transplantation