Hepato-biliary: Acute pancreatitis Flashcards
What is acute pancreatitis?
Reversible inflammatory state of the pancreas
- Mild (85%) - Mild form of interstitial edema of the gland
- Severe (15%) - Patients with pancreatic, or peripancreatic, necrosis or acute fluid collections have severe pancreatitis
What are the clinical “phases” of acute pancreatits
Early: lasts for a week
Second: weeks to months
What are causes of acute pancreatitis?
- Idiopathic
- Gallstones
- Ethanol
- Trauma
- Steroids
- Mumps
- Autoimmune
- Scorpian venom
- Hyperlipidaemia, hypothermia, hypercalcaemia
- ERCP
- Drugs
What is the pathophysiology of acute pancreatitis?
Self-perpetuating enzyme mediated autodigestion:
- Enzymes cause leaky vessels, leading to tissue oedema and inflammation
- Lipolytic enzymes -> fat necrosis
- Released fatty acids bind calcium -> white precipitates in the necrotic fat
- Proteolytic enzymes destroy aicnar tissue.
- Destruction of blood vessels causes haemorrhage
- Destruction of islet cells can result in hyperglycaemia
Why do individuals with pancreatitis get hypoglycaemia?
Due to destruction of islet cells
Why do those with pancreatitis have white patches in the necrotic fat?
Fatty acids produced by lipolytic enzyme breakdown of fat bind calcium, forming white deposits
What are symptoms of acute pancreatitis?
- Gradual/sudden severe epigastric/central abdominal pain
- Vomiting
What is characteristic of the pain experienced in acute pancreatitis?
- Radiates to the back
- Relieved by sitting forward
What are signs of acute pancreatitis?
- Tachycardia
- Pyrexia
- Can be in profound shock
- Jaundice - obstructive (oedema of the head of the pancreas compressing the lower end of CBD)
- Ileus
- Rigid abdomen +/- local/general tenderness
- Cullen’s sign
- Turner’s sign
What is Cullen’s sign?
Periumbilical ecchymoses (haemorrhagic discoloration)
What causes cullen’s sign?
Retroperitoneal haemorrhage - The retroperitoneum is connected to the gastro-hepatic ligament, then the falciform ligament, and finally to the round ligament (the obliterated umbilical vein), which tracks to the abdominal wall around the umbilicus. When a haemorrhage (from any cause) occurs, blood is able to move along these ligaments to the abdominal wall to produce ecchymoses
What is Grey Turner’s sign?
Ecchymoses or purple discolouration of the flanks.
What is the mechanism behind Grey-Turner’s sign?
A hole in the abdominal fascia. A defect in the transversalis fascia allows blood from the posterior pararenal space to move to the abdominal wall musculature and the subcutaneous tissue
What are other causes of Cullen’s sign, besides acute pancreatitis?
- Retroperitoneal bleeding
- Post surgery
- Anticoagulation
- Rectus sheath haematoma
- Ectopic pregnancy
- Ischaemic bowel
Why wouldnt there be rigidity on abdominal palpation
Because pancreas is retroperitoneal. Make sure you aren’t missing an itnra-peritoneal rigidity
Why might there be reduced bowel sounds?
Secondary to ileus in small bowel loop or transverse colon nect to pancreas
Differentials of acute pancreatits
- Perforated PU - sudden pain then levels off compared to AP (gradual reaching max due to inflammatory process),
- Erext CXR
- Acute cholecystitis/biliary colic
- AUS
- High intestinal obstruction
- AXR
- CT
- Inferior MI
- Bloods - troponin
- ECG
- Ruptured AAA
- CT
- AUS
- Mesenteric ischaemia
- CT angiogram
What investigations would you do if you thought someone had acute pancreatitis?
- Bloods - Amylase/lipase, FBC, U&Es, LFTs, Ca2+, Glucose, ABG, Lipids, Coagulation screen, CRP
- Urinary amylase
- Abdominal XR/Erect CXR
- Abdominal USS
- Contrast-enhanced spiral CT
- MRI/MRCP
- ERCP
What bloods would you do in someone with suspected acute pancreatitis?
- FBC, U&Es, LFTs
- Amylase/lipase
- LDH
- Albumin
- Ca2+
- Glucose
- ABG
- Lipids
- Coagulation screen
Why would you perform an erect CXR in someone with suspected acute pancreatitis?
To exclude a gastroduodenal perforation/pleural effusion. May also see signs of calcification
Why might you do an abdominal ultrasound in someone with acute pancreatitis?
1st line
Used to screen for possible biliary causes of pancreatitis. This is mainly used to exclude gallstones
Why would you consider doing a CT in someone with acute pancreatitis?
To assess extent/severity of pancreatic necrosis and for complications, including:
- Abscess development
- Fluid collection
- Pseudocyst
Indicated in those with
- uncertain diagnosis
- a severe attack
- clinical deterioration
- suspected local complications
Why would you do an ERCP in someone with acute pancreatitis?
Used to look at pancreatic duct for inflammatory fibrosis, tumours, gallstones. Can also be used to remove stones.
Why might you do an abdominal X-ray in someone with suspected acute pancreatitis?
Look for signs of fluid collection - retroperitoneal fluid.
Also look for ielus - sentinel loop next to inflamed organ, colon cut off sign inflammed colond ue to associated pancreas.
Why might you perform a glucose in someone with suspected pancreatitis?
Look for signs of hypo/hyperglycaemia
Why might you look at LFTs in someone with suspected acute pancreatitis?
Obstructive jaundice pattern
Look for signs of liver dysfunction caused by blockage of biliary system - e.g. gallstones which could cause pancreatitis
Why might you perform a coagulation screen in someone presenting with features of acute pancreatitis?
Look for causes of cullen’s/Grey-turner’s sign - clotting disorders
Why would you do an ABG in someone with acute pancreatitis?
Look for signs of acid/base disturbance and monitor oxygenation (to assess severity - Modified glasgow criteria)
How is amylase excreted?
Renally - renal failure will lead to accumulation
What are causes of raised serum amylase?
- Upper GI perforation
- Biliary peritonitis
- Intestinal infarction
- Macroamylasaemia
Why is a serum calcium measured in acute pancreatitis?
Look for hypocalcaemia & to assess severity - Modified glasgow criteria
Due to deposition of calcium in fat necrosis
Appears 3-8 days after acute attack
Why would you assess U+E’s in someone with suspected acute pancreatitis?
Assess severity - Modified glasgow criteria
Concernad about 3rd space fluid loss - ARF
How would you manage gallstones as a cause of acute pancreatitis?
ERCP - can remove gallstones if progressive jaundice
If mild AP then during same admission
If severe then should be delayed until inflammatory process settled
If local complications - done when these have resolved or dealt with seperately
Why might you do a CRP in someone with suspected acute pancreatitis?
Assess disease severity and prognosis
What level would you expect amylase to reach?
400 units is suggestive
>1000 is diagnostic
How long does it take amylase to intially rise?
Within 6 hours
NON SPECIFIC AND NON PROGNOSTIC
How long does it take amylase levels to fall back to normal after initial presentation of acute pancreatitis?
3-5 days - Late presentation may give false negative result
Other causes of raised amylase
Acute cholecystitis, CBD stone, perofrated PI, mesenteric ischaemia, pancreatic cancer
More specific test other than amylase that isn’t readily availble but would be ideal
Lipase
Diagnostic criteria for acute pancreatitis
- Abdominal pain consistent with acute pancreatitis
- Serum lipase (or amylase) levels at least 3x greater than the upper limit
- Characteristic findings on contrast, CT or less commonly MRI/AUS