Acute Pancreatitis

Inflammation of the pancreas

[Functions of the pancreas]

Causes

1. Gallstones 45%
2. Ethanol 35%
3. Trauma
4. Steroids
5. Mumps, coxsackie
6. Autoimmune
7. Scorpion venom
8. Hypercalcaemia (activates enzymes), hyperlipidaemia
9. ERCP
10. Drugs (steroids, thiazides)

Pathophysiology

1. Activation of proteolytic pro-enzymes contained within pancreas
2. Triggers autodigestion
3. Results in severe inflammatory reaction
   • Inflammed acinar cells and invading leucocytes produce cytokines (IL-1) and TNFalpha
   • Cytokines mediate systemic inflammatory response syndrome (SIRS)
4. Persistant inflammation leads to "pancreatic pseudocyst"
   • Collection of fluid rich in pancreatic secretions enclosed within a cyst lined with granulation tissue (as opposed to epithelium)
   • If < 5cm will resolve spontaneously; if > 5cm may beed surgical intervention and drainage
   • Conservative therapy needed for 4-6 weeks to allow cyst wall to mature
   • Surgical treatment: - Radiology-guided percutaneous drainage; endoscopic drainage; internal drainage

Clinical presentation

1. History
   • severe epigastric pain radiating to back and eased by leaning forwards
   • Accompanied by nausea and persistent vomiting
2. Examination
   • tenderness with rigid abdomen and absent bowel sounds
   • Abdominal distension due to ileus
   • bleeding in fascial planes: Grey-Turner's sign (flanks); Cullen's sign (peri-umbilical)
3. Investigations
   • Shock- tachycardia
   • Low pO2
   • High BM etc...
   • High serum amylase (>500U) or serum lipase
   • AXR: "sentinel loop", CXR - exclude perforation

Ranson Criteria

APACHE III score (acute physiology and chronic health evaluation) 

Glasgow (Imrie) scoring system

• PaO2 < 8kPa
• Age > 55years
• Neutrophils > 15 x10⁸/l
• Calcium <2.0 mmol/l - saponification
• Raised Urea >16mmol/l
• Enzymes: AST/ALT >600; LDH >600
• Albumin <32g/litre
• Sugar > 11mmol/l

Severe if score 3 or more
Should be managed in HDU setting

Complications

1. Pancreatic abscess
2. Pancreatic pseudocyst
3. Severe destructive pancreatic haemorrhage
4. Duodenal obstruction
5. Chylous ascites

Chronic Pancreatitis

1. Chronic inflammatory disease of pancreas
2. Irreversible glandular destruction
   • Early: may appear "normal"
   • Late: fibrosis and calcification
   • Cysts form within pancreas with duct dilation
3. May occur as result of recurrent acute pancreatitis

Causes

1. Alcohol
2. Smoking
3. Hereditary
4. Hypercalcaemia
5. Duct obstruction
   • Strictures
   • Gallstones
   • Cystic fibrosis

Clinical features

• Amylase usually normal
• Interferes with life and leads to opiate abuse
• Loss of exocrine function - malabsorption, steatorrhoea
• Loss of endocrine function - diabetes
• Imaging (CT/MRI-pancreas protocol): demonstrates calcification

Management

1. Dietary modification - low fat, alcohol abstention
2. Avoid opiates
3. Pancreatic enzyme supplements: -
4. Correct endocrine disturbance