Jaundice Flashcards
synthetic functions of the liver
Clotting factors
Bile acids
Carbohydrates
Gluconeogenesis, Glycogenolysis, Glycogenesis
Proteins
Albumin synthesis,
Lipids
Cholesterol synthesis, Lipoprotein and TG synthesis
Hormones
Angiotensinogen, insulin like growth factor
what roles does the liver play in detoxification
Urea production from ammonia
Detoxification of drugs
Bilirubin metabolism
Breakdown of insulin and hormones
what role does the liver play in immune function
Combating infections
Clearing the blood of particles and infections, including bacteria
Neutralizing and destroying all drugs and toxins
what storage functions does the liver play
Stores glycogen
Stores Vitamin A, D, B12 and K
Stores copper and iron
what is bilirubin
By product of haeme metabolism
Generated by senescent RBC’s in spleen
in what state is bilirubin originally found
Initially bound to albumin (unconjugated)
Liver helps to solubilise it (conjugated)
when is bilirubin elevated
pre-hepatic
Haemolysis
when is bilirubin elevated
hepatic
Parenchymal damage
when is bilirubin elevated
post hepatic
Obstructive
Aminotransferases
Enzymes present in hepatocytes
ALT more specific than AST
AST/ALT ratio can point towards ALD
Suggests parenchymal involvement
what is the difference between ALT and AST
Serum aspartate transaminase (AST) is mainly found in the liver, cardiac muscle, and other tissues while serum alanine transaminase (ALT) is predominantly found in the liver.
Alkaline phosphatase
Enzyme present in bile ducts
Elevated with obstruction or liver infiltration
Also present in bone, placenta and intestines
Gamma GT
Non specific liver enzyme
Elevated with alcohol use
Useful to confirm liver source of ALP
Drugs like NSAID’s can raise levels
Albumin
important test for synthetic function of liver
Low levels suggest chronic liver disease
Can be low in kidney disorders and malnutrition
Prothrombin time
Extremely important test for liver function
Tells degree of liver dysfunction
Used to calculate scores to decide stage of liver disease, who needs a liver transplant and who gets a liver transplant
Creatinine
Essentially kidney function
Determines survival from liver disease
Critical assessment for need for transplant
Platelet count
Liver is an important source of thrombopoietin
Cirrhosis results in splenomegaly
Platelets low in cirrhotic subjects as a result of hypersplenism
Indirect marker of portal hypertension
what are important markers for liver and kidney damage
bilirubin, aminotranderase, alkaline phosphatase, gamma gt, albumin,prothrombin time, creatinine, platelet count
symptoms of liver malfunction
Jaundice
Ascites
Variceal bleeding
Hepatic encephalopathy
definition of jaundice
Yellowing of the skin, sclerae, and other tissues caused by excess circulating bilirubin.
when is jaundice detectable
when total plasma bilirubin levels exceed 34 µmol/L
what is the differential diagnosis for jaundice
carotenemia
pre-hepatic jaundice
Increased quantity of bilirubin (Haemolysis)
Impaired transport
hepatic jaundice
Defective uptake of bilirubin
Defective conjugation
Defective excretion
post-hepatic jaundice
Defective transport of bilirubin by the biliary ducts
identifying features during history taking for pre hepatic jaundice
History of anaemia (fatigue, dyspnoea, chest pain)
Acholuric jaundice
identifying features during history taking for hepatic jaundice
Risk factors for liver disease (IVDU, drug intake)
Decompensation (ascites, variceal bleed,encephalopathy)
identifying features during history taking for post-hepatic jaundice
Abdominal pain
Cholestasis (Pruritus, pale stools, high coloured urine)
clinical examination clues for pre-hepatic jaundice
Pallor
Splenomegaly
clinical examination clues for hepatic jaundice
Stigmata of CLD (spider naevi, gynaecomastia)
Ascites
Asterixis
clinical examination clues for post-hepatic jaundice
Palpable gall bladder (Courvoisier’s sign)
investigations for liver failure
Liver screen
Hepatitis B & C serology
Autoantibody profile, serum immunoglobulins
Caeruloplasmin and copper
Ferritin and transferrin saturation
Alpha 1 anti trypsin
Fasting glucose and lipid profile
what is the most important investigative test
Ultrasound of the abdomen
why is an abdominal ultrasound important
Differentiates extrahepatic and intrahepatic obstruction
Delineates site of obstruction
Delineates cause of obstruction
Documents evidence of portal hypertension
Preliminary staging of extent of disease e.g. cancer spread
ultrasound benefits
Cheap
No radiation
Portable, widely available
Good for gallstones
High specificity
Lower sensitivity
Examines organs as well as biliary system
ct scan / MRI benefits
Better for pancreas
High specificity
High sensitivity
Examines organs
(and biliary system)
ct scan / MRI negatives
Expensive
Radiation (only for CT scan)
Requires CT / MRI scanner
ERCP
endoscopic test which we do by putting a specialised side viewing endoscope, then using the X-ray machine to find out what’s happening in the bile duct by injecting dye within the bile duct - helping to take out stones and place stents that can take care of jaundice
ERCP features
Radiation
Sedation
Complications (5%)
Failure rate (10%)
Only images ducts
Therapeutic option
MRCP features
No radiation
No complications
5% claustrophobia
Can image out with the ducts
when is therapeutic ERCP used
Acute gallstone pancreatitis
Stenting of biliary tract obstruction
Post-operative biliary complications
Complications of ERCP
Sedation related - respiratory
- cardiovascular
Procedure related
Pancreatitis
Cholangitis
Sphincterotomy
Bleeding
Perforation
when is Percutaneous Transhepatic Cholangiogram (PTC) used
ERCP not possible due to
duodenal obstruction
or previous surgery
Hilar stenting
disadvatage of Percutaneous Transhepatic Cholangiogram (PTC)
More invasive than ERCP
when is Endoscopic Ultrasound (EUS) used
Characterising pancreatic masses
Staging of tumours
Fine needle aspirate (FNA) of tumours and cysts
Excluding biliary microcalculi
why are liver biopsies important
Important for definitive diagnosis of certain conditions e.g. autoimmune hepatitis
Important to confirm diagnosis e.g. PBC, DILI
Important for staging of severity e.g. Alcoholic hepatitis, NAFLD
