Pancreatitis (44) Flashcards
What are the protective mechanisms against autodigestion of the pancreas?
- proteases released as inactive proenzymes (zymogens)
- pancreas contains trypsin inhibitor that prevents trypsin activation
- enzymes only activated in duodenum
How are digestive enzymes activated in the duodenum?
- duodenal mucosa secretes enterokinase, which converts trypsinogen–> trypsin
- trypsin then converts all other proteolytic and some lipolytic enzymes
What is acute pancreatitis?
rapid onset inflammation of the pancreas
What is chronic pancreatitis?
long-standing inflammation of the pancreas
What are the causes of acute pancreatitis?
Gallstones Ethanol (alcohol) Trauma Steroids Mumps and other viruses Autoimmune condition Scorpion/snake bite Hypercalcaemia, hypertriglyceridaemia, hypothermia ERCP Drugs (SAND: steroids and sulphonamides, azothioprine, NSAIDS, diuretics)
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What is the pathogenesis of acute pancreatitis?
- gallstones cause back pressure–> bile reflux and pancreatic juices release blocked
- if gallstones removed–> reflux of duodenal contents (activated enzymes)
- alcohol (also histamine and aspirin) inc. permeability of pancreatic duct epithelium–> acinar cell enzymes diffuse into periductal interstitial tissue–> leaks
- alcohol precipitates proteins in ducts, forming a plug that blocks–> inc. pressure
- pancreatic enzymes activated intracellularly and prematurely bc proenzymes and lysosomes mix
What are the potential consequences of acute pancreatitis due to trypsin activation?
activated trypsin can then activate:
- elastase–> vessel arrosion–> bleeding
- prothrombin–> thrombin–> thrombosis–> ischaemia
- elastase–> islet necrosis–> dec. insulin prod.–> hyperglycaemia
- phospholipase A2–> fat necrosis–> calcium sequestration–> hypocalcaemia
- vasodilation and plasma exudation–> shock
- systemic damage–> hypoxia bc lung damage and anura bc kidney damage
What are the symptoms of acute pancreatitis?
- epigastric pain radiating to back (eased by sitting forward)
- vomiting
- fevers
What are signs of acute pancreatitis?
- hypotension and tachycardia
- localised peritonitis
- Grey-Turner’s sign (bruising in flanks)
- Cullen’s sign (bruising around umbilicus)
What are differential diagnoses for acute pancreatitis?
- gallstones
- ruptured aortic aneurysms
- peptic ulcer disease/perforation
What are the investigations done for acute pancreatits?
- X-rays: erect CXR, AXR
- amylase/lipase: but there are other causes
- ultrasound: to look for gallstones
- CT of abdomen: if patient not settling
- MRCP: if gallstones suspected
- ERCP: to remove CBD GS
What is the modified glasgow criteria for assessing severity of acute pancreatitis?
PO2 Age N- raised WCC Calcium Renal: urea Enzymes Albumin Sugar - if 3 or more within 48hrs of onset--> severe pancreatitis - CRP>200 is an independent predictor
How is acute pancreatitis managed?
- fluid resus
- analgesia
- pancreatic rest (no eating)
- determine underlying cause
- if severe–> intensive care
- surgery RARELY
- only give ABs if infected necrosis
What are the systemic complications of acute pancreatitis?
- hypocalcaemia
- hyperglycaemia
- multi organ failure
- acute renal failure
- adult respiratory distress syndrome
What are the local complications of acute pancreatitis?
- pancreatic necrosis
- pancreatic abscess
- pancreatic pseudocyst
- haemorrhage due to bleeding from arroded vessels–> splenic artery life threatening
- thrombosis of splenic vein, superior mesenteric vein, portal vein
- chronic pancreatitis
