Pancreas and pancreatitis

Question 1

What is the composition of pancreatic juice?

Answer 1

Sodium bicarbonate (majority): made by small duct cells.
Enzymes: 
- amylase
- proteases
- lipase
- ribonuclease/deoxy
Water
Salts

Question 2

What’s the purpose of the bicarbonate?

Answer 2

Buffers acidic gastric juice in chyme
Denatures pepsin
Gives right pH for action of digestive enzymes
Protects mucosa

Question 3

What hormones increase the secretion of pancreatic enzymes?

Answer 3

CCK and secretin

Secretin is released in response to chyme

Question 4

What effect does vagal stimulation have on pancreas secretion?

Answer 4

Increases secretion of aqueous component sand enzymes in cephalic phase
- important since enzyme synthesis is time consuming

Question 5

What is chronic pancreatitis?

Answer 5

Ongoing inflammation of the pancreas, leading to irreversible destruction of endocrine and exocrine function

Question 6

What causes chronic pancreatitis?

Answer 6

TIGAR-O

Toxico-metabolic:

• ALCOHOL = 90%
• Chronic renal failure
• Hypercalcaemia: blocks duct
• Smoking

Idiopathic

Genetics

• SPINK1: codes protease inhibitor Ca
• trypsin inactivator genes/CF genes

Autoimmune
- Associated with PBC, IBD, Sjorgens

Recurrent acute

Obstructive

• SOO stenosis
• ductal obstruction or adenocarcinoma

Question 7

Signs and symptoms of chronic pancreatitis?

Answer 7

• Recurrent epigastric pain, radiating to the back
• Diabetes
• Weight loss
• Steatorrhoea
• Jaundice can se secondary to obstruction of common bile duct

Question 8

How much acinar tissue must be loss to see malabsorption and steatorrhoea?

Answer 8

90%

Also: deficiency in ADEK

Question 9

Who is most likely to get chronic pancreatitis?

Answer 9

Middle-aged men with repeated bouts of acute pancreatitis

Question 10

What theories are there about the pathophysiology of chronic pancreatitis?

Answer 10

4 key pathological changes:

1. Continuous chronic inflammation
2. Fibrous scarring
3. Loss of pancreatic tissue
4. Duct strictures with formation of calculi

Question 11

Why does destruction of the pancreas occur?

Answer 11

Increased trypsinogen activation and increased trypsin, or impaired trypsin clearance, measn that proteins form plugs in ducts which become calcified and cause obstruction.
Ductal hypertension and more damage ensues.

Question 12

What effect can alcohol have on pancreatitis?

Answer 12

Impairs Ca regulation, increasing trypsinogen activation

Question 13

What investigations can help diagnose pancreatitis?

Answer 13

MRCP
CT: speckled calcification
X-ray: calcification
Endoscopic US

Question 14

What blood tests are helpful in diagnosis?

Answer 14

Serum amylase/lipase: slightly elevated. High in acute; atrophy of pancreas means there’s less

Serum trypsin: low in chronic, but not sensitive enough

Serum calcium/TAG

Question 15

What faecal tests are helpful?

Answer 15

Chymotrypsin

Human pancreatic elastase 1

Question 16

How is pancreatitis managed?

Answer 16

Avoiding alcohol
Careful with opiates
Pancreatic supplements: reduce fat excretion and improve absorption
- lipase needs to be taken throughout meal

Low fat diet

PPI: optimise duodenal pH for enzyme activity

Octreotide
Amitriptyline
Steroids: only if abstinent to reduce inflam

Lithiotripsy to break calculi

Thoracoscopic splancnicecvtomy

Pancreatomy: however, will have diabetes

Question 17

What are complications of chronic pancreatitis?

Answer 17

Pseudocysts
Pancreatic ascites
Extrahepatic obstructive jaundice
Duodenal stenosis
Portal/splenic vein thrombosis, leading to PTN and gastric varices
Peptic ulcers