Jaundice Flashcards
where is haemoglobin broken down?
the spleen
What breaks down haemoglobin in the spleen?
macrophages
What is haem broken down into?
biliverden
What is biliverden converted to?
bilirubin
How is bilirubin carried to the liver?
Albumin
What conjugates bilirubin in the liver?
UDP-glucoronyl-transferase
In the small intestine what do bacteria convert bile to?
urobilinogen
How does the liver get rid of conjugated bilirubin?
Bile
urobilinogen is _____ to form urobilin which gives faeces its brown colour
oxidised
Some urobilinogen is reabsorbed and then re-excreted by the kidney. This does what to urine?
causes it to be yellow
Prehepatic jaundice is caused by?
the haemolysis of RBCs
Examples of conditions causing pre-hepatic jaundice?
haemolytic anemias, new born jaundice
Jaundice from pre-hepatic causes is usually…?
mild
Blood tests would show what levels of conjugated and unconjugated bilirubin in pre-hepatic jaundice?
normal conjugated, raised unconjugated (saturated enzyme)
clinical features that may present with pre-hepatic jaundice?
anemia, splenomegaly, gall stones
Potential causes of hepatic jaundice?
hepatitis, hepatotoxicity, cirrhosis, congenital disorders
What two possibilities are the cause of hepatic jaundice (pathophysiological processes)?
- disruption in the ability to uptake or conjugate bilirubin 2. oedema of the hepatocytes causing intrahepatic obstruction of the bile ducts
Causes of disruption in ability to conjugate bilirubin in hepatic jaundice
reduced UDP enzyme: leads to increased unconjugated bilirubin but otherwise normal LFTs (Gilbert syndrome)
Intrahepatic obstructive jaundice would potentially cause what blood abnormalities?
raised unconjugated and conjugated bilirubin - highest being conjugated as it is an obstructive issue
LFTs in hepatic jaundice may show?
very raised AST and raised ALT, slightly raised GGT and ALP
A low albumin in hepatic jaundice indicates?
ongoing chronic condition
What is the process behind extrahepatic jaundice?
obstruction of bile drainage through the biliary system
Main causes of extrahepatic jaundice?
gallstones, cancer of the head of the pancreas
Hepatic jaundice may cause what changes to stools and urine?
Depending on obstruction may have paler stools and darker urine. depends on level and is not a diagnostic indicator
Extrahepatic jaundice causes what changes to stools and urine? why?
pale stools and dark orange urine. Conjugated bilirubin isnt getting into the gut to be oxidised but may be excreted by the kidneys
Blood results concerning bilirubin in extrahepatic jaundice?
normal unconjugated and increased conjugated as there is normal liver function, just issues in excretion.
LFTs in extrahepatic jaundice?
slightly raised AST, ALT, ALP and GGT - more from back pressure through the biliary system than liver issues
A history involving country of origin might point to what causes of jaundice?
Hep B and Hep C
A history involving duration of illness might point to what causes of jaundice?
- prolonged, weight loss - malignancy 2. short, prodromal - hepatitis
A history involving outbreaks of jaundice in the community might indicate what causes of jaundice?
Hep A
A history involving IVDU and tattoos might indicate what causes of jaundice?
Hep B or Hep C
A history of alcohol with jaundice might indicate?
chronic liver disease
A family history of jaundice might indicate?
hereditary conditions such as Gilbert’s syndrome (lack of enzyme UDP)
A history of surgery with jaundice might indicate?
biliary tract surgery or carcinoma
A history of fever and rigors with jaundice might indicate?
cholangitis
A smooth hepatomegaly might indicate what causes of jaundice?
hepatitis, extrahepatic causes
A knobbly, irregular hepatomegaly with jaundice?
metastases or cirrhosis
Splenomegaly with jaundice might indicate?
Portal hypertension from chronic disease, viral hepatitis, or increased RBC lysis
Ascites with jaundice might indicate?
cirrhosis
A palpable gallbladder with jaundice may indicate?
blocked biliary tract or carcinoma of the pancreas
Investigations for jaundice?
USS, Serology, FBC, LFTs, Auto-antibodies, Albumin, Pro-thrombin, WCC
USS might indicate what causes of jaundice?
rules out obstruction, features of chronic liver disease, size of bile ducts, tumours and gallstones,
Serology might indicate what causes of jaundice?
hepatitis, CMV, HIV
Hepatitis might show what LFTs?
raised AST and ALT, small raise in ALP
Extrahepatic jaundice might show what LFTs?
raised ALP and small raise AST and ALT
Chronic liver disease associated jaundice might show what LFTs
increased pro-thrombin time, low serum albumin
Raised WCC might indicate what causes of jaundice?
cholangitis, infection, abscesses
Anti-AMA might indicate?
PBC
