[41] Acute Pancreatitis Flashcards
What is acute pancreatitis characterised by?
Self-perpetuating pancreatic enzyme-mediated autodigestion
What can cause hypovolaemia in acute pancreatitis?
Oedema and fluid shifts
What fluid shifts cause hypovolaemia in acute pancreatitis?
Extracellular fluid gets trapped in the gut, peritoneum, and retroperitoneal space
What % of acute pancreatitis cases are mild?
80%
What will 20% of acute pancreatitis cases develop to?
Serious and life threatening disease
How fast does the progression of acute pancreatitis occur?
May be rapid
What can severe cases of acute pancreatitis develop into?
Necrotising pancreatitis
What may cases of necrotising pancreatitis be further complicated by?
Infection
What % of cases of necrotising pancreatitis are further complicated by infection?
50%
When does acute pancreatitis occur?
When there is abnormal activation of digestive enzymes within the pancreas
What causes the abnormal activation of digestive enzymes in acute pancreatitis?
Inappropriate activation of inactive enzyme precursors called zymogens inside the pancreas, most notably trypsinogen
What normally happens to trypsinogen?
It is converted to it’s active form (trypsin) in the duodenum
What is the physiological role of trypsin?
To aid in the digestion of proteins
What happens to trypsinogen during an episode of acute pancreatitis?
Trypsinogen comes into contact with cathpepsin, which is a lysosomal enzyme, which activates it
What does the inappropriate activation of trypsinogen to trypsin in acute pancreatitis cause?
- Inflammation
- Oedema
- Vascular injury
- Cell death via necrosis or apoptosis
What can pancreatitis be classified into?
Mild and severe
What is the classification of pancreatitis based on?
Wether the predominant response to cell injury is inflammation (mild) or necrosis (severe)
What happens in mild pancreatitis?
There is inflammation and oedema of the pancreas
What happens in severe pancreatitis?
There is necrosis of the pancreas, and nearby organs may become injured
What are the causes of acute pancreatitis?
- Gallstones
- Ethanol
- Trauma
- Steroids
- Mumps
- Autoimmune
- Scorpion venom
- Hyperlipidaemia
- Hypothermia
- Hypercalcaemia
- ERCP
- Emboli
- Drugs
- Pregnancy
- Neoplasia
What are the symptoms of acute pancreatitis?
- Pain
- Nausea and vomiting
- Diarrhoea
Describe the pain in acute pancreatitis?
It is gradual or sudden onset severe epigastric or central abdominal pain, which radiates o the back
What might relieve the pain in pancreatitis?
Sitting forwards
What are the signs of acute pancreatitis?
- Increased HR
- Fever
- Jaundice
- Shock
- Ileus
- Rigid abdomen, with local or general tenderness
- Periumbilical bruising, or bruising in flanks
What investigations can be done into acute pancreatitis?
- Serum amylase and lipase
- ABG
- AXR
- Other imaging
- CRP
What is considered to be raised serum amylase?
>1000u/mL
Is the degree of elevation of serum amylase related to the severity of the disease in acute pancreatitis?
No
Why may serum amylase be misleading in acute pancreatitis?
It can be normal, even in severe pancreatitis
How is amylase secreted?
Renally
What is the result of amylase being excreted renally?
Renal failure will increase levels
Is serum amylase a specific test for acute pancreatitis?
No
What other conditions can cause raised serum amylase?
- Cholecystitis
- Mesenteric infarction
- GI perforation
How does serum amylase rises in cholecystitis, mesenteric infarction, and GI perforation compare to in acute pancreatitis?
These conditions cause the levels to rise less than in acute pancreatitis
How does testing serum lipase compare to serum amylase in acute pancreatitis?
It is more sensitive and specific for pancreatitis, especially when related to alcohol, rises earlier, and falls later
What may be shown on an AXR in acute pancreatitis?
- No psoas shadow
- ‘Sentinel loop’ of proximal jejunum from ileus