Biochemistry

Question 1

What are the neuromuscular causes of dysphasia?

Answer 1

• Muscular: muscular dystrophy, myasthenia gravis
• Neurological: stroke, Parkinson’s disease, MS
• Weakened muscles, impaired coordination (in elderly)

Question 2

What are the narrowing of throat/oesophagus causes of dysphasia?

Answer 2

• Throat cancer/oesophageal cancer
• Sacs/rings in oesophagus
• GORD (scars resulting from acid reflux)

Question 3

What is the change in epithelium of Barrett’s oesophagus?

Answer 3

Squamous epithelium to metaplastic columnar epithelium.
Dysplasia arises with a segment of Barrett’s and is a reason to consider referral for treatment rather than surveillance.

Question 4

What are the risk factors of Barrett’s oesophagus?

Answer 4

• Chronic GORD
• Hiatus hernia
• Smoking
• Central obesity
• 7x more common in males
• > 50 yrs
• Inherited predisposition

Question 5

What is the oesophagus made up of?

Answer 5

• Top third - skeletal muscle (voluntary)
• Middle third - skeletal and smooth muscle
• Bottom third - smooth muscle (involuntary)

Question 6

How does H.pylori cause peptic ulcers?

Answer 6

• Increase HCl production > inflammation in antrum > increased gastric + somatostatin
• Disruption of mucosal defence and destroys gastric surfactant

Question 7

How do NSAIDs cause peptic ulcers?

Answer 7

• Cytotoxic epithelial > disrupt barrier
• COX1 inhibition > decrease mucus secretion + blood flow to epithelial cells (decrease repair mechanism)
• COX2 inhibition > decrease angiogenesis > decrease repair mechanism
• COX1 + COX2 inhibition > increase HCl production

Question 8

What are the risk factors for peptic ulcers?

Answer 8

• Smoking
• Drinking alcohol above recommended intake
• FH of peptic ulcer disease
• Physical stress e.g. major trauma or surgery or ICU admission
• Hypersecretory syndromes which increases production of stomach acid e.g. Zollinger-Ellison syndrome

Question 9

What are the causes and management of a Mallory-Weiss tear?

Answer 9

Possible causes:
- Alcohol intoxication
- Self-induced vomiting
- Pregnancy (hyperemesis)
Management: wait for bleeding to stop, treat underlying cause

Question 10

What is the Glasgow BlatchFord score?

Answer 10

Done pre-endoscopy to identify patients who can be safely managed as outpatient is score = 0.
Urea, Hb, systolic BP, pulse, maleana, syncope, hepatic disease, cardiac failure

Question 11

What is the Rockall score?

Answer 11

Risk of re-bleed, >3 carries significant risk

Age, shock, comorbidity, diagnosis, major SRH