Jaundice Flashcards
What is jaundice
Accumulation of bilirubin in the skin giving a yellow/orange pigmentation and a significant itch
Where is jaundice most noticeable
The sclera of the eye
How are patients with jaundice described to look
Icteric
How does bilirubin affect the circulation of haem
Haem from RBCs being reprocessed is converted into biliverdin and then into bilirubin which allows the circulation of haem
Describe how bile is formed
Haem converted into bilibverdin then bilirubin has to be conjugated and from that bilirubin is excreted from the liver cells into the biliary tree forming bile
What is the purpose of the gall bladder
It can store bilirubin or it can contract and squeeze the bilirubin into the small intestine through the biliary duct
What happens to bile after it is secreted into the small intestine
Conjugated bilirubin is passed down to the large intestine where it is reabsorbed, converted to urobilinogen which can be excreted through the kidneys, giving urine its colour
What is the role of urobilinogen
Can be excreted through the kidneys but some will pass through the stool and give stercobilin - the colour pigment for the stool
Some urobilinogen is reabsorbed into the liver and reprocessed
What are the different classifications of jaundice
Pre-hepatic
Hepatic
Post-hepatic
Describe pre-hepatic jaundice
Excess of bilirubin being processed and passed into the bile duct
More conjugated bilirubin being produced and still more bilirubin in the blood which can’t be conjugated and therefore will accumulate in the blood and skin causing jaundice but not affecting the urine or stool colours
What are common causes of pre-hepatic jaundice
Haemolytic anaemia
Post transfusion - bad match
Neonatal (maternal RBC induced)
Describe hepatic jaundice
Problem with hepatic cell therefore the unconjugated bilirubin isn’t conjugated in the liver cell
No conjugated bilirubin is passed into the biliary system and no conjugated bilirubin is passed into the blood
What are the signs of hepatic jaundice
No pigment in the stool - it will be pale
No pigment in the urine because unconjugated bilirubin can’t be passed to the kindney
Describe post-hepatic jaundice
Conjugated bilirubin being passed into the bile system but a blockage causing this to flow back through the hepatic cells and into the blood
What are the signs of post-hepatic jaundice
No pigment passing to the stools - pale stools
An excess of pigment in the blood, passing to the urine causing dark urine
What are the common causes of blockage in post-hepatic jaundice
Intrahepatic - primary biliary sclerosis is an autoimmune disease destroying the bile tree and its pathways
Extrahepatic - biliary system can be blocked by either gallstones or tumours
When is bile secreted from the gall bladder
Food entering the duodenum will cause a reflex contraction of the gall bladder releasing bile from the common bile duct to enter the duodenum from the ampulla
What is cholecystitis and what will this cause
Inflammation of the gall bladder
Because the gall bladder sits against the diaphragm, at the bottom and behind the liver, it will cause inflammation of the diaphragm
What are the symptoms of cholecystitis
Referred pain in shoulder tip
Abdominal pain in right side radiating to the back
Pain from eating fatty foods - stimulates bile release
Usually gallstones - rarely cholangiocarcinoma
What investigations can be carried out on patients with jaundice
Ultrasound - detects dilated bile channels within the liver and biliary tree
Plain radiographs - can be used to see small vessels within the liver that can’t be seen in an ultrasound
ERCP
What is an ERCP
Endoscopic Retrograde Cholangio Pancreatography
Best way to illuminate the biliary system and also allows the possibility of carrying out procedures to the biliary duct eg - stented ampulla
How is ERCP carried out
Using an endoscope to put a cannula into the biliary tree from the duodenum
From that, dye is injected that goes towards the pancreatic system and upwards towards the liver where it branches forming the biliary tree to the hepatic cells
What tumours may cause an obstruction leading to jaundice
Cholangiocarcinoma - can arise anywhere in the biliary system
Pancreatic cancer - head of the pancreas
Give examples of common pancreatic diseases
Pancreatitis
Cystic fibrosis
