Acute pancreatitis Flashcards
Give an endocrine function of the pancreas.
Alpha cells of the pancreas produce glucagon
Beta cells produce insulin.
Give an exocrine function of the pancreas.
Acinar cells produce digestive enzymes.
What are zymogens? Give one example.
Zymogens are inactive forms of pancreatic enzymes, which can be activated by cleavage by proteases. They are stored in vesicles called zymogen granules with protease inhibitors. An example is tryspinogen.
Define acute pancreatitis.
Auto-digestion of the pancreas by its own digestive enzymes.
Describe the pathophysiology of acute pancreatitis and give the 2 main causes.
If acinar cells become damaged (by alcohol) or pancreatic ducts blocked (by gallstones), zymogens may be prematurely activated to enzymes. These digest the pancreatic tissues.
How does alcohol cause pancreatitis?
- Increased zymogen secretion, decreased fluid and bicarbonate production -> increased viscosity of pancreatic fluids -> duct blockage -> distension, increased pressure -> chaotic membrane trafficking -> zygmogen granules may fuse with lysosomes. ->
Tripsinogen -> tripsin -> activates other enzymes -> destruction. - Causes acinar cells to release inflammatory cytokines, which attracts strong immune reaction. Neutrophils come to the pancreas and release proteases (which activate zymogens) and superoxides.
- Undergo oxidative metabolism, forming reactive oxygen species’ which damage the pancreas.
How do gallstones cause pancreatitis?
Gallstones get lodged in the sphincter of Oddi, which blocks release of pancreatic juices.
How does liquefactive haemorrhagic necrosis occur?
Pancreatic tissue destruction from proteases and inflammatory response causes blood vessel leakage and rupture. This causes swelling, which causes lipases to destroy peripancreatic fat. The digestion and bleeding can liquefy tissue (=LHN).
How does disseminated intravascular coagulation occur?
DIC is when tiny blood clots form throughout the body, using up clotting factors, making it paradoxically easier to bleed. It can be caused by acute pancreatitis.
What is the main cause of death in people with acute pancreatitis and what is the physiology?
Adult respiratory distress syndrome (ARDS). Inflammation causes blood vessels to become leaky, which causes difficulty breathing.
How does acute pancreatitis cause hypovolaemia?
- Oedema and fluid shifts - ECF trapped in gut, peritoneum and retroperitoneum.
- Blood vessel damage causing haemorrhage
What might cause fever, leukocytosis, abdominal pain, loss of appetite and a palpable mass in a patient with acute pancreatitis? Describe the physiology.
Pancreatic pseudocyst.
Fibrous tissue surround liquefactive necrotic tissue and the resulting cavity fills with pancreatic juice (pain, anorexia,mass).
It can grow and rupture, leading to inflammation, and/or infection (fever and leukocytosis).
How is pancreatic pseudocyst diagnosed?
Abdo CT
Bloods: raised amylase, lipase and bilirubin.
Give 5 causes of acute pancreatitis.
Idiopathic (10%) Gallstones (35%) Ethanol abuse (35%) Trauma (1.5%) Steroids Mumps Autoimmune Scorpion stings Hypertriglyceridemia/ hypercalcaemia ERCP (5%), Emboli Drugs
What is Cullen’s sign?
Periumbilical bruising due to necrosis-induced haemorrhage spreading to soft tissue in the periumbilical area.