MRCP Gastro

Question 1

What electrolyte abnormality do patients with cirrhosis commonly encounter?

Answer 1

Patients with cirrhosis are frequently hyponatraemic. This is a function of an inability to excrete free water.

Question 2

Why are cirrhotic pts hypoNa?

Answer 2

Inability to excrete free water (increased ADH levels and systemic vasodilation)

Decreased vascular resistance
Increased plasma volume
Low serum sodium.

This is a function of an inability to excrete free water (increased ADH levels and systemic vasodilation contribute, but the underlying mechanism is complex and not entirely understood).

Secondary hyperaldosteronism will result in total body sodium overload but not necessarily hypernatraemia. Remember that the sodium level is a concentration, therefore if the amount of solvent (water) is increased then it will not necessarily rise.

The development of ascites is related to this process but is not the cause of dilution.

There is decreased vascular resistance, increased plasma volume and low serum sodium.

Question 3

Which enzyme catalyses conjugation of bilirubin?

Answer 3

glucuronyl transferase

Question 4

What kind of impairment is seen in Dubin-Johnson syndrome?

Answer 4

conjugation is normal, but excretion from the hepatocyte into the bile is impaired, resulting in a conjugated bilirubinaemia.

Question 5

where is bili conjugated?

Answer 5

hepatocytes

Question 6

Causes of villous atrophy

Answer 6

Coeliac disease
Tropical sprue
Hypogammaglobulinaemia
Gastrointestinal lymphoma
Whipple’s disease
Cow’s milk intolerance

Question 7

What is the best therapeutic option for hepatitis B related decompensated liver disease?

Answer 7

Entecavir or tenofovir are the most appropriate medications and can be used in combination
They provide rapid control of HBV DNA levels

Watch out for lactic acidosis

Question 8

MoA of Entecavir

Answer 8

Deoxyguanosine analogue
Inhibits viral DNA polymerase reducing viral DNA synthesis
nucleoside/nucleotide antiviral agents

Question 9

Why are Entecavir or tenofovir contraindicated in HIV?

Answer 9

Both drugs have anti-HIV action and so their use as monotherapy is contraindicated in HIV-positive patients, as it may lead to HIV antiviral drug resistance

Question 10

Treatment of pyogenic liver abscess?

Answer 10

ampicillin, gentamicin and metronidazole
drainage

Question 11

Complications of Hep B

Answer 11

fulminant hepatic failure,
cholangiocarcinoma,
cryoglobulinaemia

Question 12

Complications of Hep C

Answer 12

Glomerulonephritis
Cryoglobulinaemia
Thyroiditis;
autoimmune hepatitis; PAN;
polymyositis; porphyria cutanea tarda

Question 13

Complications of endovascular repair of abdominal aortic aneurysms?

Answer 13

Aorto-enteric fistulae –> presents with GI bleed –> strongly positive faecal occult blood (FOB) suggests significant GI haemorrhage.

Question 14

30F
If a blood film reveals the presence of spherocytes.

Which of the following is the next most useful investigation?

Answer 14

The results given indicate a haemolytic anaemia of which spherocytes are typical and given the age of the patient the most likely cause is immune.

First step in analysis -> determine whether the process is hemolytic or not
Direct antiglobulin test

Question 15

Histological features of UC?

Answer 15

Mucosal inflammation PLUS

• General inflammatory cell infiltration
• Goblet-cell mucus depletion
• Crypt abscesses
• Crypt shortening
• Branching.

Continuous inflammation, worsening from rectum to caecum.

Question 16

Histological features of Crohns

Answer 16

Transmural inflammation, with:

• Lymphocytic infiltrates and lymphoid aggregates
• Fissures
• Preservation of crypt architecture
• Non-caseating granulomata.

There is patchy inflammation from mouth to anus.

Question 17

Investigations reveal:

Total bilirubin 11 µmol/L (1-22)
Alkaline phosphatase 145 U/L (45-105)
AST 100 U/L (1-31)
ALT 150 U/L (5-35)
Albumin 40 g/L (37-49)
Ferritin 434 µg/L (15-300)
Ultrasound of the abdomen reveals an echo bright appearance of the liver and gallstones in the gallbladder.

Which of the following is the most likely cause of her liver disease?

Answer 17

NASH gives a hepatitic picture with echobrightness on USS

Question 18

What are the normal functions of vasoactive intestinal peptide?

Answer 18

increased intestinal secretion of water and electrolytes
peripheral vasodilation
inhibition of gastric acid secretion, and
potentiates acetylcholine action on salivary glands.

Question 19

What biochemical abnormalities are associated with VIPoma?

Answer 19

Raised urea+calcium
raised plasma pancreatic polypeptide
hypokalaemic acidosis (loss of alkaline secretions)
achlorydia, and
mildly raised glucose.

Question 20

double bubble sign is indicative of?

Answer 20

Duodenal atresia
common in downs syndrome

Question 21

In which part of the body is conjugated bilirubin metabolised to urobilinogen?

Answer 21

Conjugated bilirubin passes into the enterohepatic circulation and the bilirubin which evades this system is metabolised by bacteria, primarily in the large intestine, to urobilinogen, then stercobilinogen and eventually oxidised to stercobilin.

Question 22

What do Islet beta cells produce?

Answer 22

insulin and amylin, as well as C peptide, pro-insulin and GABA.

Question 23

Match cells to what they make
Islet D
F cells
A cells
Gastric chief cells
Gastric parietal cells

Answer 23

Islet D cells produce somatostatin
F cells produce pancreatic polypeptide
A cells produce glucagon
Gastric chief cells produce pepsinogen
Gastric parietal cells produce acid and intrinsic factor.

Question 24

From where is the hormone somatostatin released?

Answer 24

Pancreas-delta cells
strong inhibitor of insulin and glucagon secretion

Question 25

A patient presents with haematemesis. An oesophagogastroduodenoscopy detects a bleed in the lesser curvature of the stomach.

Which of the following arteries is most likely to be the cause of the bleeding?

Answer 25

The** right gastric artery **arises from the hepatic artery or the left hepatic artery supplies the pylorus and travels along the lesser curvature of the stomach, supplying it, and anastomosing with the left gastric artery.

Question 26

pancreaticoduodenal artery supplies

Answer 26

upper and lower duodenum and the head of the pancreas

Question 27

Blood supply to the greater curvature of the stomach

Answer 27

Gastro-omental arteries

Question 28

Origin of the right gastric artery?

Answer 28

Arises from the hepatic artery / the left hepatic artery supplies the pylorus and travels along the lesser curvature of the stomach, supplying it, and anastomosing with the left gastric artery.

Question 29

Name one infective cause of chronic diarrhoea ? Tx

Answer 29

Giardia -Giardia lamblia.
Metronidazole

Question 30

Crohn’s disease vs UC
anal

Answer 30

Anal tags, fissures, perianal fistulae and abscesses- all in crohns not UC

Question 31

What diseases are potentially reversible in haemochromatosis ?

Answer 31

Cardiomyopathy
Dermal pigmentation

Question 32

What diseases are usually irreversible in haemochromatosis ?

Answer 32

diabetes, cirrhosis, hypogonadism, and arthropathy

Question 33

Clostridium difficile is which class of bacteria?

Answer 33

Gram-positive anaerobic

Question 34

psuedomembranous colitis/c. diff causes: abx

Answer 34

broad-spectrum antibiotics, most commonly:
* cephalosporins
* broad-spectrum penicillins
* quinolones
* and clindamycin