WEEK 5 - Pancreatitis

Question 1

Where is the pancreas located?

Answer 1

Located posterior to the stomach between the duodenum on the right and the spleen on the left

Question 2

What are the four ANATOMICAL parts of the pancreas and where are they located?

Answer 2

1. Head - tucked into the curve of the duodenum
2. Neck - 2cm long, overlies the superior mesenteric artery
3. Body - passes over the aorta and L2
4. Tail - touches the spleen

Question 3

What are the two FUNCTIONAL parts of the pancreas?

Answer 3

1. Endocrine portion - produces hormones

2. Exocrine portion - produces digestive enzymes and alkaline fluid

Question 4

What are the four cell types of the endocrine pancreas and what are their functions?

Answer 4

1. Alpha - secrete glucagon for increasing BGLs
2. Beta - secrete insulin for decreasing BGLs
3. Delta - secrete somatostatin and gastrin
4. F - secrete pancreatic polypeptide, for suppression of appetite in response to meal ingestion

Question 5

What do the Islets of Langerhans do?

Answer 5

Lie between Acinar cells, produce and secrete hormones

Question 6

Where do endocrine cells of the pancreas lie?

Answer 6

Adjacent to blood vessels to allow hormones to be secreted directly into circulation

Question 7

Which cells make up the exocrine part of the pancreas? What do they secrete?

Answer 7

Acinar cells, secrete digestive enzymes:

• Proteases, for breakdown of proteins
• Amylase, for breakdown of carbohydrates
• Lipase, for breakdown of fat into FFAs

Ductal cells, secrete:
- Alkaline fluid, for neutralising chyme and for fat digestion and absorption, released in response to secretin

Question 8

How does the pancreas protect itself?

Answer 8

• By secreting proteases in their inactive forms (zymogens)
• Trypsin inhibitor - prevents early activation of proteases while in the pancreas
• Alkaline fluids - flush enzymes into the duodenum

Question 9

Pancreatitis is caused by?

Answer 9

I - Idiopathic
G - Gallstones
E - Ethanol/alcohol
T - Trauma
S - Steroids
M - Mumps/viruses
A - Autoimmune
S - Scorpion stings
H - Hypertriglyceridaemia/ hypercalcaemia
E - Endoscopic retrograde cholangiopancreatography
D - Drugs

Question 10

Pathophys of pancretitis?

Answer 10

Unknown

Theory = injury to acinar cells = early activation of proenzymes causing autodigestion of the pancreas

Question 11

What are the three phases of pancreatitis?

Answer 11

1. Acinar cell injury
2. Acute inflammatory response
3. Systemic complications

Question 12

What characterises phase 1 of pancreatitis?

Answer 12

• Biliary tract obstruction = increases intraductal pressure, pancreatic juices back up and leak into interstitial tissue
• Lipase causes fat breakdown = injury causes inflammatory response
• Oedema = impairs blood flow = ischaemia
• Proenzyme activation due to defective intracellular transport = pancreatic autodigestion

Question 13

What characterises phase 2 of pancreatitis?

Answer 13

• Injury to acinar cells and pancreatic tissue destruction = release of proinflammatory cytokines = inflammatory response
• Inflammation leads to vascular changes and cellular events

Question 14

What are the causes of primary acinar cell injury in pancreatitis?

Answer 14

• Alcohol
• Trauma
• Viruses
• Drugs

Question 15

What vascular changes occur in phase 2 of pancreatitis?

Answer 15

• Vasoconstriction due to histamine release
• Vasodilation = increases hydrostatic pressure = pushes fluid into interstitial tissue
• Increased vascular permeability = pushes exudate into interstitial tissue
• Increased blood viscosity

Question 16

What cellular events occur in phase 2 of pancreatitis?

Answer 16

• Chemotaxis - movement of leukocytes towards the site of inflammation down a chemical gradient
• Phagocytosis - leukocytes engulf and destroy dead cells
• Activation of plasma protein systems

Question 17

Describe the steps that allow leukocytes to move from their place of origin to the site of pancreatitis?

Answer 17

• Margination - movement of leukocytes from central axial column to the periphery
• Rolling - Leukocytes move along the epithelial surface
• Activation - Of adhesion molecules (selectins and integrins) on the surface of leukocytes
• Adhesion - Leukocytes stick to the endothelial wall
• Diapedesis - Movement of leukocytes from the endothelial wall to the interstitial tissue through gap junctions

Question 18

What are some systemic complications that occur in phase 3 of pancreatitis?

Answer 18

• Shock
• Cardiac - myocardial depression, decreased TPR, hypotension
• Lungs - PO, ARDS
• Renal - pre-renal failure, acute tubular necrosis
• Sepsis
• Disseminated intravascular coagulation - use of all clotting factors so pt continues to bleed
• MODS

Question 19

Treatment for pancreatitis?

Answer 19

Fluid resuscitation

Vasopressors to vasoconstrict

Question 20

Clinical manifestations of pancreatitis?

Answer 20

• Epigastric pain - central and upper abdo
• N and V
• Abdo distension and tenderness
• Fever
• Leukocytosis
• Steatorrhea - excessive undigested fat in faeces due to lack of lipase
• Transient hyperglycaemia - damaged alpha cells = release of glucagon = increased BGLs
• Hypotension
• Tachycardia
• Hypoxaemia
• Elevated urea and creatinine

Question 21

Diagnosis of pancreatitis?

Answer 21

• Elevated serum amylase
• Elevated serum lipase
• Elevated urine amylase and serum CRP
• Radioactive imaging

Question 22

Treatment of pancreatitis?

Answer 22

Does not exist

Question 23

Management of pancreatitis?

Answer 23

• Fluid resuscitation + colloids - prevent hypovolaemia, increase TPR
• Pain management - opioids, PCA
• Nutrition - TPN for vomiting, NGT favourable, intake vs output charts
• ABs - only if there is an infection
• Surgery - pancreatic resection or removal of gallstones

Question 24

Chronic pancreatitis is due to?

Answer 24

Chronic alcohol abuse

Question 25

Pathophysiology of chroinc pancreatitis?

Answer 25

Chronic inflammation leads to fibrosis, strictures, ductal obstruction and pancreatic cysts

Question 26

How to manage chronic pancreatitis?

Answer 26

Lifestyle changes, pain relief, fat free diet