Biliary Colic Flashcards
Briefly describe the pathophysiology of biliary colic
Bile is formed from cholesterol, phospholipids, and bile pigments (products of haemoglobin metabolism). It is stored in the gallbladder, before passing into the duodenum upon gallbladder stimulation.
Gallstones form as a result of supersaturation of the bile. There are three main types of gallstones: cholesterol, pigment and mixed.
Briefly differentiate between the 3 types of gallstones
Note: cholesterol, pigment and mixed
Cholesterol stones
- Composed purely of cholesterol, from excess cholesterol production
- There is a well recognised link between poor diet, obesity, and cholesterol stones
Pigment stones
- Composed purely of bile pigments, from excess bile pigments production
- Commonly seen in those with known haemolytic anaemia
Mixed stones
- Comprised of both cholesterol and bile pigments
Briefly describe the anatomy of the biliary tree
What is biliary colic?
Biliary colic occurs when the gallbladder neck becomes impacted by a gallstone. There is no inflammatory response, yet the contraction of the gallbladder against the occluded neck will result in pain.
What are the risk factors for biliary colic?
Classically the common risk factors for gallstone disease are colloquially described as the “5 F’s”:
- Fat
- Female
- Fertile
- Forty
- Family history
Other recognised risk factors include pregnancy and oral contraceptives*, haemolytic anaemia (specifically for pigment stones), and malabsorption (such as previous ileal resection or Crohn’s disease).
Why does oral contraceptive use increase the risk of biliary colic?
Oestrogen causes more cholesterol to be secreted into bile.
What are the clinical features of biliary colic?
The pain is typically sudden, dull, and colicky in nature. It is often focused in the right upper quadrant although it may radiate to the epigastrium and/or back. The pain may be precipitated by the consumption of fatty foods and the patient often complains of nausea / vomiting. In general, once pain relief has been started, symptoms often settle quickly.
Why does the consumption of fatty food lead to biliary colic?
Fatty acids stimulate the duodenum endocrine cells to release cholecystokinin (CCK), which in turn stimulates contraction of the gallbladder.
How common are clinical features of biliary colic?
Studies have shown for those who are symptomatic, over 50% will present as biliary colic and 35% as an acute cholecystitis.
What is Murphy’s sign?
Whilst applying pressure in the RUQ, ask the patient to inspire. Murphy’s sign is positive when there is a halt in inspiration due to pain, indicating an inflamed gallbladder. This can be achieved more accurately with an ultrasound, namely the sonographic Murphy sign.
What investigations should be ordered for biliary colic?
Note: laboratory investigations
Certain blood tests can help in the initial evaluation of suspected cases:
- FBC and CRP- assess for the presence of any inflammatory response, which will be raised in cholecystitis
- LFTs- biliary colic and acute cholecystitis are likely to show a raised ALP (indicating ductal occlusion), yet ALT and bilirubin should remain within normal limits (unless a Mirizzi syndrome, discussed below)
- Amylase (or lipase)- to check for any evidence of pancreatitis
A urinalysis, including a pregnancy test if relevant, should be performed to exclude any renal or tubo-ovarian pathology.
What investigations should be ordered for biliary colic?
Note: imaging
A trans-abdominal ultrasound is one of the most sensitive modalities for visualising gallstone disease and is typically used first line to investigate suspected gallstone pathology.
If results from US scans are inconclusive, further imaging options are available. The gold standard investigation for gallstones is Magnetic Resonance Cholangiopancreatography (MRCP), largely replacing ERCP for diagnostic purposes. MRCP can show potential defects in the biliary tree caused by gallstone disease, with a sensitivity approaching 100%.
What are the 3 things observed on an ultrasound scan of bilary colic?
Three specific areas are often visualised on US:
- The presence of gallstones or sludge (the start of gallstone formation)
- Gallbladder wall thickness (if thick walled, then inflammation is likely)
- Bile duct dilatation (indicates a possible stone in the distal bile ducts)
Briefly describe labels A-D on MRCP
MRCP image showing stones in the distal common bile duct: A
- A: gallbladder with stones
- B: stone in bile duct
- C: pancreatic duct
- D: duodenum
Briefly describe the conservative management of biliary colic
Patients with biliary colic should be prescribed analgesia (regular paracetamol +/- NSAIDs +/- opiates analgesia).
The patient should be advised about lifestyle factors that may help control symptoms (and help with future surgery), such as a low fat diet, weight loss, and increasing exercise.