1. Acute pancreatitis

Question 1

How can acute pancreatitis be distinguished from chronic?

Answer 1

Acute pancreatitis has limited damage to the secretory function of the gland, with no gross structural damage developing

Question 2

What are the causes of acute pancreatitis?

Answer 2

GET SMASHED:

• gall stones (most common in women)
• ethanol (most common in men)
• trauma
• steroids
• malignancy
• autoimmune
• scorpion sting
• hyperlipidaemia/hypercalcaemia/hyperparathyroidism
• ERCP
• drugs: Azathioprine, NSAIDs, or Diuretics

Question 3

What is the pathogenesis of acute pancreatitis?

Answer 3

Causes will trigger a premature and exaggerated activation of the digestive enzymes within the pancreas. The resulting pancreatic inflammatory response causes an increase in vascular permeability and subsequent fluid shifts. Enzymes are released into the systemic circulation.

Question 4

What does release of enzymes into systemic circulation cause?

Answer 4

Autodigestion of fats (resulting in a ‘fat necrosis’) and blood vessels (sometimes leading to haemorrhage in the retroperitoneal space). Fat necrosis can cause the release of free fatty acids, reacting with serum calcium to form chalky deposits in fatty tissue, resulting in hypocalcaemia.

Question 5

What are clinical features of acute pancreatitis?

Answer 5

• sudden onset of severe acute epigastric pain which radiates to the back
• nausea and vomiting
• epigastric tenderness (with/without guarding)
• Cullen’s and Grey turners sign
• tetany
• cause specific e.g. jaundice with gall stones

Question 6

What causes tetany?

Answer 6

Enzymes released cause fat necrosis which release free fatty acids which react with serum calcium

Question 7

What are differential diagnosis for acute pancreatitis?

Answer 7

Abdominal pain that radiates through to the back include:

- abdominal aortic aneurysm, renal calculi, chronic pancreatitis, aortic dissection, or peptic ulcer disease.

Question 8

What investigations would you consider?

Answer 8

• serum amylase
• LFTs
• (serum lipase)
• abdo USS
• (AXR and CXR)
• (contrast CT)

Question 9

What levels of serum amylase is diagnostic?

Answer 9

3x the upper limit of normal

Question 10

What else can raise serum amylase?

Answer 10

Bowel perforation, ectopic pregnancy, DKA

Question 11

Why is USS done?

Answer 11

When underlying cause is unknown, used to identify gallstones or duct dilation

Question 12

What might an abdominal x-ray show?

Answer 12

‘sentinal loop sign’. This is a dilated proximal bowel loop adjacent to the pancreas, which occurs secondary to localised inflammation

Question 13

When might you request an CXR?

Answer 13

look for pleural effusions or signs of acute respiratory distress (complication of pancreatitis)

Question 14

When might you request contrast CT?

Answer 14

If the initial assessment and investigations prove inconclusive. If performed after 48hrs from initial presentation, it will often show areas of pancreatic oedema and swelling, or any non-enhancing areas suggestive of pancreatic necrosis

Question 15

Give an example of risk scoring system for acute pancreatitis?

Answer 15

Modified Glasgow criteria (first 48hrs after admission) - score of >= 3 considered to have severe pancreatitis

Question 16

What are the different criteria for the modified Glasgow scoring system?

Answer 16

PANCREAS:

• pO2 <= 8kPa
• age > 55
• neutrophils (wcc) > 15x109L
• Calcium <2mmol/L,
• Renal function (Urea) >16mmol/L,
• Enzymes LDH>600U/L or AST>200U/L,
• Albumin <32g/L,
• Sugar (blood glucose) >10mmol/L

Question 17

What is involved in management?

Answer 17

Treat underlying cause e.g. gallstones(early laparoscopic cholecystectomy), otherwise supportive treatment:

• fluid resuscitation and oxy therapy as required
• NG tube if profuse vomiting
• catheterisation to monitor urine output and start fluid balance chart (due to potential for third spacing)
• analgesia (opioid, IV paracetamol?)

Question 18

When might antibiotics be used and what type?

Answer 18

In confirmed cases of pancreatic necrosis for prophylaxis against infection
- broad spectrum e.g. meropenem, imipenem

Question 19

What are local complications of acute pancreatitis?

Answer 19

• necrosis

- pseudocysts

Question 20

When should necrosis be suspected, how is it confirmed and treated?

Answer 20

• suspected in patients with evidence of persistent systemic inflammation for more than 7-10 days after the onset of pancreatitis
• confirmed by CT imaging
• treatment will often warrant pancreatic necrosectomy (delayed until walled of necrosis has occurred in 3-5 weeks)

Question 21

how can pancreatic necrosis be diagnosed?

Answer 21

Pancreatic necrosis is prone to infection and should be suspected if there is a clinical deterioration in the patient associated with raised infection markers (or from positive blood culture or changes of low density within the pancreas on CT). Definitive diagnosis of infected pancreatic necrosis can be confirmed by a fine needle aspiration of the necrosis.

Question 22

what is a pancreatic pseudocyst?

Answer 22

a collection of fluid containing pancreatic enzymes, blood, and necrotic tissue

Question 23

where are pancreatic pseudocysts seen?

Answer 23

they can occur anywhere within or adjacent to the pancreas, however are usually seen in the lesser sac obstructing the gastro-epiploic foramen by inflammatory adhesions..