GIT investigations

Question 1

what are the functions of the functions of the liver and where is it located

Answer 1

upper right quadrant 
glycogen store and syn 
protein metab  
lipid metab 
bile syn  
excretion and detox 
iron storage and vit  storage ADE

Question 2

what are damaging factors of liver disease

Answer 2

poison, drugs, infection, inadequate perfusion, autoimmune, tumours

Question 3

what are the systemic effects of liver disease

Answer 3

jaundice, oestrogen excess, clubbing, pigmentation, ascites

Question 4

what are the signs of systemic liver disease

Answer 4

neonatal jaundice 
jaundice
finger clubbing
sider naevi - liver metablises oestorgen 
gynaecomastia

Question 5

what are the routine LFT’s

Answer 5

ALP / ALT, bilirubin, albumin, total protein, GGT (gamma glutamyl transferase)

Question 6

what are the tests for hepatocyte damage

Answer 6

ALT (alanine
aspartate - AST
related by cellular damage - and CK

ALT is more specific for liver than AST as ast also found in muscle and RBC’s

Question 7

what is a tumour marker for hepatocyte damage

Answer 7

alpha fetoprotein

Question 8

what is the role of the markers of biliary tract damage

Answer 8

show impaired excretory function - increased conjugated bilirubin, ALP and yGT

Question 9

what do elevated ALP and yGT mean in biliary tract damage

Answer 9

alp - increased production of cells lining the bile canniculi and overflow into blood - cholestasis

yGT elevated due to structural damage

Question 10

how can you tell the difference between bone and liver ALP

Answer 10

separated by electrophoresis

Question 11

what are biochemical markers of fibrosis in the liver

Answer 11

seen in imaging

ELF score - likelihood of fibrosis

Question 12

what are the different forms of measure of bilirubin

Answer 12

total
unconjugated - prehepatic and hepatic
conjugated - post hepatic and hepatic

Question 13

what is the amount of bilirubin needed to from jaundice

Answer 13

more than 40-50 umol/L

Question 14

describe bilirubin metabolism

Answer 14

from Hb and insoluble in water and travels in plasma
taken by liver and conjugated by UDP GT - more soluble
excreted in bile and used for fat digestion / absorption
urobillogen in urine - darker colour
stercobillogen in faeces - acted on by bacteria

Question 15

what is the pre hepatic aetiology of hyperbillirubinaemia

Answer 15

haemolysis

ineffective erythropoiesis

Question 16

describe the inborn error of bilirubin meytablolism

Answer 16

deacrsed activity of UDP GT - gilberts cripplers nailers syndromes

reduced ability to excrete bilirubin glucuronide

Question 17

how do you distinguish between hepatitis and obstructive jaundice

Answer 17

AST/ALT - with normal ALP = hepatitis

AST pr ALT normal and elevated ALP = obstructive jaundice

Question 18

what are the urine test differences of pre-hepatic, hepatic and post-hepatic disease

Answer 18

pre - unconjugated bilirubin = no urinary bili
hepatic - dependant on degree of obstruction
post - obstruction - dark urine and pale stools

Question 19

what are direct and indirect pancreatic function tests

Answer 19

invasive tests are gold standard - look for secretin, CCk lung tests

indirect - pancreatic enzyme analysis (elastase)
trypsinogen (IRT)