Jaundice Flashcards
What is obstructive jaundice?
It is a type of jaundice that occurs due to narrowing or obstruction of the extrahepatic biliary tract
- the blockage causes blockage of the bile and causes hepatitis
- the blockage of bile also prevents the bile from goimg into the intestines
What are the causes of obstructive jaundice?
- gallstones
- pancreatic CA of the head
- cholangitis
- pancreatitis
- cholangiocarcinoma
- choledochal cysts
- biliary stricture
What are the common symptoms that patients with obstructive jaundice present with?
- RUQ pain
- pale stools, dark urine
- pruritis
- nausea and vomiting
- decolouration of their skin and eyes
What is Courvoisiers Law?
-the presence of a palpable gallbladder that is non-tender with mild painless jaundice is unlikely to be gallstones but likely to be malignant
What do we look for in a patient with obstructive jaundice?
- vitals: check if patient has fever or haemodynamically stable
- inspection: jaundice, pallor
- abdo exam:ascites, hepatomegaly, abdominal scars,enlarged gallbladder, splenomegaly
- digital rectal exam
- cervical and supraclavicular LN
- bony tenderness
- respiratory exam
What clinical tests must be done?
1-LFT's to confirm obstructive jaundice typical picture is elevated bilirubin and ALP 2-FBC 3. U&E and CRP 4. Amylase 5.Tumour markers(CA19-9) 6.PT/PTT 7. Blood culture
What does hemoglobin break up into?
- heme
2. globin
What protein carries the unconjugated bilirubin around?
albumin
Is unconjugated bilirubin lipid soluble or not?
-lipid soluble
Is conjugated bilirubin water soluble?
Yes
What are the characteristics of pre-hepatic jaundice?
- the urine/stools are normal
- unconjugated hyperbilirubinaemia
- check stool for (ova, parasites, cysts)
- Direct Coombs test for autoimmune haemolytic anaemia
What are the causes of pre-hepatic jaundice?
- inherited anaemias-spherocytosis, sickle cell anaemia, thalassemia, G6DP
- acquired: malaria, SLE
What are the characteristics of hepatic jaundice?
- mixed picture with normal stools and dark urine sometimes
- decreased albumin
- increased AST and ALT
- On abdo exam: increased nodulariy and echogenicity in cirrhosis
What are the causes of hepatic jaundice?
- infective causes:
- viral hepatitis(HBV)
- CMV, TB, EBV - Liver cirrhosis
- alcoholic liver disease
- sarcoidosis/amyloidosis - Hepatotoxic drugs:
- alcohol. isoniazid, paracetamol, augmentin - inherited decreased unconjugated bilirubin
- gilberts syndrome
- crigler najjar 1 and 2
What is the presentation of cholestatic jaundice?
- dark urine, pale stools
- conjugated hyperbilirubinaemia
- increased ALP and GGT before ALT,AST
- Abdo ultrasound usually depicts dilated ducts >8mm which you then have to do ERCP,MRCP or PTC
What are the causes of cholestatic jaundice?
- intraluminal
- mural
- extramural
What are the intraluminal causes?
- gallstones
- parasites like schistosomiasis
What are the mural causes?
- cholangitis
- cholelithiasis
- choledochal cysts
- biliary strictures caused by post ERCP
- biliary strictures caused by gallstones o hronic pancreatitis
What are the extra-luminal causes?
- carcinoma of the head of the pancreas
- Mirizzi’s syndrome
What is the function of the biliary tract?
To carry bile from the liver
What is bile made up of?
- water
- electrolytes
- bile pigment which is mostly bilirubin
- bile salts
- phospholipid
- mucus
- cholesterol
How is bilirubin formed and how does obstructie jaundice cause pale stools?
Bilirubin is conjugated in the liver and travels down the biliary duct because it is soluble. If there is an obstruction then there is backup of the bilirubin and increased conjugated bilirubin in circulation.
Stercobilinogen is the derivative of bilirubin that causes the brown colour of poo and once absorbed it is urobilongen. So if there is an obstruction then there is no way for the stercobilinogen to get to the stool hence pale stools
Why does the urine still turn dark?
Because of the increased concentration of the conjugated bilirubin
What are bile salts?
Metabolites of cholesterol that are different to bile pigments becuase they actually serve a function and are not just waste
What are the 2 functions of bile salts?
- Helps absorbs lipids in the GIT
- To ensure cholesterol is soluble in bile
95% of bile salts are going to be reabsorbed in the terminal ileum and reused by the liver
What happens if the bile salts do not function?
- malabsorption leading to steatorrhea
2. pruritis
What is Hartmann’s pouch?
It is when a pouch develops adjacent to the cystic duct
What does cholecyskinin do?
It leads to the contraction of the gallbladder and relaxation of the sphincter of Oddi caused by food intake
What are the 2 main causes of obstructive jaundice?
- gallstones
2. malignancy
What are the luminal causes of obstructive jaundice?
- gallstones
- worms
- hydatid cysts
- blood clots as found in haemobilia due to trauma
This type is usually associated colicky right upper quadrant pain
What are the biliary wall causes of obstructive jaundice?
- Congenital: biliary atresia, choledochal cyst
- Inflammatory: sclerosing cholangitis
- Trauma
- malignant cholangiocarcinoma
What are the causes of obstructive jaundice outside of the biliary tract?
- swollen lymph nodes from TB, gastric cancer, lymphoma
- adavanced gallbladder pathology like Mirizzi’s syndrome, chronic pancreatitis, pancreatic cyst
- Malignancy like peri-ampullary ca and ca of the pancreatic head
Why does peri-ampullary ca have a better prognosis than pancreatic head ca?
- It has a slower progression
2. It affects the biliary tree faster so patients show up earlier
What are the pathophysiological signs and symptoms of obstructive jaundice?
- hepatomegaly (congestion)
- raised total bilirubin, raised ALP and GGT
- low serum albumin, decreased clotting factors
- Dilation of the biliary tree above the obstruction
- Increased risk of infection (cholangitis)
What are the pathophysiological signs and symptoms below the obstruction?
- pale stools
- decreased stercobilinogen and urobilinogen but still dark urine
- Acute renal failure
- decreased absorption of vitamins which leads to deficiency in vitamin k which leads to dysfunction in clotting factors 2, 7, 9, 10
What imaging would you get for obstructive jaundice?
- chest X-ray
- Abdominal X-ray to look for gallstones(radio-opaque ones)
- ultrasound -gold standard
- Others:
- CT
- MRCP(magnetic resonance cholangiopancreatogram) which helps us visualise the biliary tract
- ERCP-CONTRAST introduced from the bottom(endoscopic retrograde cholangiopancreatogram)
- PTC-percutaneous transhepatic cholangiogram
When would an ERCP be indicated?
When we are unsure of the diagnosis and want to take a biopsy, put in a stent or stone removal
What is the peri-operative management of the patient with obstructive jaundice?
- vitamin K 5-10mg IV daily and fresh frozen plasma
- Broad spectrum IV antibiotics which treat the cholangitisprevent SIRS
- Start patient on fluids to maintain renla function
- Put in catheter to monitor the urinary output
