LFTs, Jaundice and Bilirubin, Investigations

Question 1

pre-hepatic cause of elevated bilirubin?

Answer 1

haemolysis - increase quantity of bilirubin

impaired transport

Question 2

hepatic cause of elevated bilirubin?

Answer 2

parenchymal damage
defective uptake
defective conjuagtion
defective excretion

Question 3

post-hepatic cause of elevated bilirubin?

Answer 3

obstructive

defective transport of bilirubin by biliary ducts

Question 4

what is bilirubin?

Answer 4

by product of haeme metabolism

Question 5

what and where is bilirubin generated?

Answer 5

in the spleen, by senescent RBCs

Question 6

when is bilirubin a) conjugated, and b) unconjugated?

Answer 6

a) conjugated when solubilised by liver

b) unconjugated when initially bound to albumin

Question 7

what are aminotransferases?

Answer 7

enzymes, present in heptaocytes

Question 8

which is more specific, ALT or AST?

Answer 8

ALT

Question 9

what is the function of aldosterone?

Answer 9

hormone that affects blood pressure, also regulates Na and K in blood

Question 10

what does AST/ALD ration indicate? what does it suggest?

Answer 10

ALD - alcohol liver disease,

suggests parenchymal involvement

Question 11

what is alkaline phosphatase?

Answer 11

enzyme, present in bile duct

Question 12

elevated alkaline phosphatase indicates..?

Answer 12

obstruction or liver infiltration

Question 13

where is alkaline phosphatase present, other than liver?

Answer 13

bone, placenta, intestines - therefore doesn’t always indicate problem with the liver

Question 14

what is gamma GT?

Answer 14

non specific liver enzyme

Question 15

when is there elevated gamma GT?

Answer 15

alcohol use

Question 16

what is gamma GT useful for?

Answer 16

confirming that elevated alkaline phosphatase has come from liver

Question 17

what can also elevate gamma GT levels?

Answer 17

NSAIDs

Question 18

what is albumin important for?

Answer 18

indicating synthetic liver function levels

Question 19

what does decreased albumin suggest?

Answer 19

CLD - chronic liver disease

Question 20

what other causes of low albumin are possible?

Answer 20

kidney disorders and malnutrition

Question 21

what does prothrombin time indicate?

Answer 21

the level of liver dysfunction

Question 22

what is prothrombin time used for?

Answer 22

calculating scores to decide stage of liver disease as well as who gets liver transplants

Question 23

what does creatinine measure?

Answer 23

kidney function

Question 24

what does creatinine determine?

Answer 24

survival from liver disease, also need for transplant

Question 25

what does cirrhosis result in?

Answer 25

splenomegaly, hypersplenism, liver scarring

Question 26

what is platelet count and cirrhosis indirect markers of?

Answer 26

portal hypertension

Question 27

normal levels of bilirubin?

Answer 27

17μmol/L

Question 28

bilirubin levels in jaundice?

Answer 28

34μmol/L (doubled)

Question 29

when bilirubin is conjugated (i.e. hepatic and post-hepatic causes of jaundice) what symptoms present?

Answer 29

dark coloured urine as bilirubin has been excreted by kidneys

Question 30

history - prehepatic jaundice?

Answer 30

history of anaemia, fatigue, dyspnoea, chest pain | acholuric jaundice

Question 31

history - hepatic jaundice?

Answer 31

IVDU, drugs, ascites, vatical bleeding, encephalopathy

Question 32

history - post hepatic Jaundice?

Answer 32

abdo pain, cholestasis, itching, pale stools, high coloured urine

Question 33

examination - prehepatic jaundice?

Answer 33

pallor, splenomegaly

Question 34

examination - hepatic jaundice?

Answer 34

CLD signs - spider naevi, gynaecomastia | ascites, flapping tremor

Question 35

examination - post hepatic jaundice?

Answer 35

Courvoisier's sign - palpable gall bladder

Question 36

Tests for Jaundice

Answer 36

liver screen - hep B&C serology, serum immunoglobulins, Alpha 1 anti trypsin, Caeruloplasmin and Cu, fasting glucose and lipid profile.

Question 37

investigations for Jaundice?

Answer 37

most important - US of abdomen

Question 38

what will US of abdomen show?

Answer 38

whether its extra/intrahepatic obstruction, site and causes of obstruction, evidence of portal hypertension, staging of disease

Question 39

US v.s. MRI/CT

Answer 39

US - cheap, no radiation (CT), widely available, high specificity, low sensitivity MRI/CT - expensive, radiation (CT), better for pancreas, high sensitivity and specificity

Question 40

ERCP v.s. MRCP

Answer 40

MRCP - diagnostic, no radiation or complications ERCP - therapeutic, radiation, sedation issues (cardio and rest), procedural issues (pancreatitis and cholangitis), failure rate of 10%

Question 41

PTC - uses | Percutaneous Transhepatic Cholangiogram

Answer 41

more invasive and is used for more severe obstructions - | hilar stenting, when ERCP is not available

Question 42

uses of EUS - endoscopic ultrasound

Answer 42

characterising pancreatic masses, staging of tumours, FNAs of tumours/cysts