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Flashcards in Liver Function Tests Deck (20):
0

Signs of hepatic disease

Jaundice
Pruritis
Nausea and vomiting
Hepatomegaly
Ascites
Spider naevi
Dark urine and pale stools

1

Causes of liver disease

Infection
Adverse drug reaction
Alcohol abuse
Obesity
Cancer

2

Normal blood concentrations

Bilirubin 5-17micromol/l
Hepatocellular:
Alanine (ALT) <50iU/l
Obstruction:
Alkaline phosphatase 39-17iU/l
Gamma-glutamyl transpeptidase 0-70iU/l male 0-40iU/l female
Synthetic function:
Albumin 30-48g/l
Coagulation INR 1-1.2

3

Stages of haem breakdown

Haem-> iron+globin
|
Biliverdin
|
Insoluble bilirubin
|
Liver
|
Soluble bilirubin
Biliary excretion

4

Conditions where bilirubin might be altered

Biliary obstruction (choleostasis)
Hepatocellular damage
Haemolysis

5

Conditions where aminotransferases maybe altered

Hepatocellular damage
Leak out of damaged cells-> large increase in blood
Detection of paracetamol overdose
ALT more specific to liver damage



6

Conditions where Alkaline phosphatase might be altered

Present in canicular and sinusoid membranes of liver
Increased in choleostasis
But also produced by bone and placenta so increased in pregnancy
Raised in infiltration of the liver-> metastasis

7

Conditions where Gamma GT's might be altered

Present in manny tissues
Increased by induction
Alcohol
Carbamazepine
Barbiturates
Phenytoin
Rifampincin
Increased in choleostasis
May be increased in cellular damage
Look at mean corpuscular volume as we'll

8

Conditions where albumin might be altered

Measure of synthetic activity of the liver
Indicates a change over longer term-> 16-24 days

9

International normalised ratio

Prothrombin time
Indicates synthetic activity
Coagulation factors have a short half life so indicates change acute and chronic

10

Hepatitis LFT results

ALT and AST raised
ALP increased or normal
Bilirubin increased or normal
GGT increased or normal
Albumin only effected in late stages
INR raised or normal

11

Cholestasis LFT results

ALP raised
GGT raised
Bilirubin raised as not excreted
ALT and AST raised or normal
Albumin normal, synthetic function not effected by choleostasis
INR raised or normal

12

LFT chronic liver disease

GGT raised
Bilirubin raised
Albumin decreased
INR increased
ALP, ALT, AST raised or normal

13

Pre hepatic jaundice

Problem before liver
Insoluble bilirubin produced faster than the liver can conjugate it
Haemolytic anaemias such as spherocytosis
Gilbert's syndrome-> decreased UDP- glucuranosyl transferase-> conjugated bilirubin

14

Hepatocellular jaundice

Transaminases leak out
Liver can't conjugate bilirubin
Reduced excretion

15

Choleostasis

Cholesterol blockage of bile duct
Intra hepatic:
Primary biliary cirrhosis-> autoimmune damage to duct
hepatocellular damage
Pregnancy
Extra hepatic:
Gall stones
Cancer in head of pancreas

16

Obstructive jaundice

Choleostasis
GGT and ALP not excreted so are raised
Liver can conjugate but not excrete bilirubin
Water soluble bilirubin excreted in urine

17

Other complications, ascites

Accumulation of fluid in peritoneal cavity
Oedema secondary to hypoproteinaemia
Sodium retention due to secondary hyperaldosteronism
Portal hypertension
Treat with diuretics or surgery

18

Encephalopathy

Neuropsychiatric symptoms
Personality changes
Disorientation
Confusion and drowsiness
Sensitivity to centrally acting drugs
Ammonia produced by gut isn't exerted by liver-> reacts with neurotransmitters
Rx. Neomycin/metronidazole and lactulose

19

Other complications of liver disease

Impaired coagulation
Gastric bleeding rx ranitidine
Bleeding of oesophageal varies rx beta blockers, octreotide