liver/GI Flashcards
list 4 functions of the liver
glucose/fat metabolism
detoxification and excretion
protein synthesis
defence against infection
what does the liver detoxify/excrete
bilirubin
ammonia
drugs/hormones/pollutants
which proteins does the liver synthesise?
albumin
clotting factors
define hepatitis
inflamed liver
what is 1 of the major consequences of chronic liver disease?
susceptibiliy to infection
how does blood flow into the liver?
via the portal vein and hepatic artery
how is the normal liver arranged?
in a regular way - acinar/lobular models
where does the portal vein and hepatic artery lie
together, with a small bile duct in the portal tract (each of the corners of hexagon model)
blood flows into a system of WHAT that bathe liver cells?
sinusoids
arranged in plates, before exiting via hepatic (central) vein
what is the hepatic vein aka
central vein
what is the central vein aka
hepatic vein
liver cells within the lobule can be divided into which zones? why is this significant?
zones 1-3
receive progressively less oxygenated blood
what are the 2 types of liver injury?
acute and chronic
what are the 2 outcomes of acute liver injury?
liver failure or recovery
what are the 3 outcomes of chronic liver injury?
liver failure
recovery
cirrhosis
what are some causes of acute liver injury?
viral (A, B, EBV) drug alcohol vascular obstruction congestion
what are some causes of chronic liver injury?
alcohol
viral (B, C)
autoimmune
metabolic (iron, copper)
what may acute liver injury result in?
damage and loss of cells
chronic damage eventually leads to what?
fibrosis
what is the severest form of fibrosis termed?
cirrhosis
how does acute liver injury usually present?
malaise nausea anorexia jaundice rarer: confusion, bleeding, liver pain, hypoglycaemia
how does chronic liver injury usually present?
ascites oedema varices malaise anorexia wasting easy bruising itching hepatomegaly abnormal LFTs rarer: jaundice, confusion
define cirrhosis
scarring and disorganisation of liver structure
what do LFTs look @
serum bilirubin
albumin
prothrombin time
do serum liver enzymes give indication of liver function?
no
do LFTs give indication of liver function?
some
define jaundice
raised serum bilirubin
what are the 2 types of jaundice?
unconjugated (pre-hepatic)
conjugated (cholestatic) [includes hepatic and post hepatic]
what is cholestasis?
decrease in bile flow due to impaired secretion by hepatocytes/obstruction of bile flow through bile ducts)
is liver disease hepatic or post hepatic?
hepatic
is bile duct obstruction hepatic or post hepatic?
post hepatic
what does cholestatic jaundice include?
hepatic and post-hepatic
what is urine in pre-hepatic jaundice like?
normal
what are stools in pre-hepatic jaundice like?
normal
what are LFTs in pre-hepatic jaundice like ?
normal
what is urine in cholestatic (hepatic/post hepatic) jaundice like?
dark
what are stools in cholestatic (hepatic/post hepatic) jaundice like?
may be pale
do u get itching in cholestatic (hepatic/post hepatic) jaundice?
maybe
what are LFTs in cholestatic (hepatic/post hepatic) jaundice like?
abnormal
if there’s dark urine, pale stools and itching … what don’t they have?
pre-hepatic jaundice
why may u have biliary pain?
due to gallstones
why may u have rigorss?
bile duct stone(s)
which history is V important w the liver?
drug/herbs! idiosyncratic reaction is important sis
what should u look at when looking at social history in someone w/ liver issues?
alcohol !
potential hepatitis contact (sex, IVDU, travel, certain foods)
family Hx rarely helpful
what is a rigor?
sudden feeling of cold w/ shivering, accompanied by temp rise often w copious sweating
what tests will be done for jaundice ?
liver enzymes
biliary obstruction
further imaging
what can sickle cell cause?
jaundice
why can sickle cell cause jaundice?
bc sickle cells do not live as long as normal RBC they die faster than the liver can filter them out.
bilirubin from these broken down cells builds up in the system
where do most gallstones form
in the gallbladder
what are gallstones usually made up of?
80% cholesterol
30% pigment
± calcium
what are the 2 main types of gallstones?
cholesterol (usually yellow-green)
pigment (darker and made of bilirubin)
if u have gallstones in the gallbladder, do get biliary pains and cholecystitis (inflammation of gallbladder)?
yes
define cholecystitis
inflammation of the gallbladder
if u have gallstones in the gallbladder, will u get obstructive jaundice?
maybe!
if u have jaundice in the gallbladder, will u get cholangitis/pancreatitis?
no
define cholangitis
inflammation of the bile duct
what is the difference btwn cholecystitis and cholangitis
cholecystitis = inflammation of gallbladder cholangitis = inflammation of bile duct
if u have gallstones in the bile duct, will u get biliary pain?
yes
if u have gallstones in the bile duct, will u get cholecystitis (inflammation of gallbladder)?
no
if u have gallstones in the bile duct, will u have obstructive jaundice/pancreatitis/cholangitis (inflammation of bile duct)
yes
is fat intolerance/indigestion and upset bowel associated with gallstones presentation?
no
what is cholecystectomy ?
removal of gallbladder
90% of ppl w obstruction have what ?
dilated bile ducts
what is ALT?
alanine aminotransferase
why might there be low levels of ALT in the blood ?
expected/normal
why might there be high levels of ALT in the blood ?
liver disease ! v high levels (more than 10x usually due to acute hepatitis, sometimes viral infection
what is the commonest reason for drug withdrawal from formulary?
jaundice
what is DILI?
drug induced liver injury
what are the types of DILI
hepatocellular
cholestatic
when looking at DILI, what is important?
not what drugs they are taking
but what they started RECENTLY
what are the most common drugs for DILI?
ABs
what do cyp450 enzymes do
metabolise potentially toxic compounds incl drugs, bilirubin
what is the most common cause of acute liver failure?
paracetamol
how is paracetamol OD managed
N acetyl cysteine (NAC)
is liver damage detectable after a paracetamol OD?
not usually until at least 18h after
what are some causes of ascites ?
chronic liver disease
neoplasia
what is the pathogenesis of ascites like ?
systemic vasodilation can lead TO portal hypertension (also incr intrahepatic resistance n low serum albumin can contribute )
this can also result in secretion of RA, NA and ADH thus fluid retention
how can ascites be managed?
]diuretics
fluid n salt restriction
fat accumulation within hepatocytes is termed WHAT?
steasosis
what can a fatty liver result in ?
alcohol hepatitis
cirrhosis
what is the main cause of liver death in the UK
ALD (alcohol liver disease)
what are some causes of portal hypertension
cirrhosis
fibrosis
portal vein thrombosis
what happens w portal hypertension?
increased hepatic resistanc/splanchnic blood flow can lead to varices and splenomegaly
what is the commonest serious infection in cirrhosis
spontaneous bacterial peritonitis
why are liver patients vulnerable to infection?
bc they have:
- impaired reticula-endothelial dysfunction
- reduced opsonic activity
- leucocyte function
- permeable gut wall
end stage liver disease is represented by what?
cirrhosis
what is the safest analgesic to prescribe to someone w/ liver disease?
paracetamol
bc sensitive to opiates
NSAIDs cause renal failure
autoimmune hepatitis requires what for diagnosis?
liver biopsy
do antihistamines help w cholestatic (bile ducts) itch?
they are little help
cholestyramine (cholesterol lowering, also anti-diarrhoea)
what are some risk factors for NAFL (non alcohol fatty liver)
obesity
diabete
hyperlipidaemia
what is the commonest cause of mildly elevated LFTs?
NAFL
why do liver patients get ascites?
high BP in the veins that bring blood to the liver (portal hypertension), which is usually due to cirrhosis.
In people with a liver disorder, ascitic fluid leaks from the surface of the liver and intestine and accumulates within the abdomen. a combo of factors is responsible:
they include the following:
- portal hypertension
- fluid retention by the kidneys
- alterations in various hormones and chemicals that regulate body fluids
acute hepatitis is when?
less than 6m
chronic hepatitis is when?
over 6m
describe a common acute hepatitis patient
can be asymptomatic general malaise (tiredness, discomfort) myalgia (muscle pain) upset GI abdo pain ± jaundice (pale stools, dark urine)
what are characteristic features of jaundice stool/urine sample
pale stools
dark urine
what are the 2 causes of acute hep
infectious (viral vs non viral)
non-infectious
list some viral infectious causes of acute hep
hep A, B etc
herpes viruses
list some non viral infectious causes of acute hep
spirochaetes
mycobacteria
parasites
bacteria
list some non-infectious causes of acute hep
alcohol NAFL drugs toxins/poisoning pregnancy
describe a common chronic hep patient
can be asymptomatic/non specific symptoms
± signs of chronic liver disease (clubbing, dupuytren’s contracture, spider naevi etc)
LFTs can be ormal
compensated - jaundice, ascites, low albumin etc
what are some common signs of chronic liver disease
clubbing
dupuytren’s contracture
spider naevi
what are oesophageal varices
v dilated submucosal veins in lower third of oesophagus
most often a cause of portal hypertension, commonly bc of cirrhosis. strong tendency to develop bleeding
what are the 2 types of chronic hep causes?
infectious n non-infectious
list some infectious causes of chronic hep
hepatitis B ± D
hep C
hep E
what are some non-infectious causes of chronic hep?
alcohol NAFL drugs toxins autoimmune
how can hep A be transmitted?
faeco-oral !!!!!
ingesting contaminated food/water
person-to-person contact
what are some risk factors of hep A
travel
household
sexual contact (MSM)
IVDU
how are the different hep’s linked by transmissions? any trends?
A & E: faecal-oral route (travel, foooood)
B & C: via blood (childbirth, IVDU, sex)
does hep A develop to chronic?
nope
does hep E develop to chronic?
nah
does Hep C develop to chronic?
usually !
does hep B develop to chronic?
in around 20%, but the younger u are the higher the risk
what is hep A aka
HAV
how can hep A be managed
supportive
monitor LFT
manage close contacts
primary prevention vaccinations
risk of chronic infection in Hep E is only to who?
immunosuppressed patients
how can hep E be managed
if acute: supportive
if chronic: reverse immunosuppression
what is hep E aka
HEV
what is hep B aka
HBV
how is hep B acquired
blooooododddd
what is Hep C aka
HCV
what can hep c result in
cirrhosis
linked to liver cancer (hepatocellular carcinoma)
how can u prevent Hep C
no vaccine
previous infection doesn’t confer immunity either :/
BUT
u can screen blood products n have universal precautions when handling bodily fluids :)
also have lifestyle modification eg needle exchanges
helicobacter pylori is involved in the pathogenesis of what?
peptic ulcer disease
bacterial infection is a frequent cause of what ?
diarrhoea
clostridium difficile infection results when ?
broad spectrum antimicrobials allow this bacteria to overgrow in the gut :@
can result in diarrhoea in susceptible host patients (particularly elderly n immunocompromised)
what kills most swallowed pathogens
gastric acid
when are u classed as having diarrhoea
3+ loose/liquid stools in 24h
what are some infection causes of diarrhoea
intraluminal infection
systemic infections eg sepsis, malaria DON’T FORGET BITCH
what are some non-infective causes of diarrhoea
cancer chemical eg poisoning, side effects IBD malabsorption endocrine eg T4 radiation
with intraluminal infection, WHAT is key?
history taking !
how does onset of diarrhoea differ?
acute onset: viral/bacterial
chronic: parasites/non-infectious
how do the characteristics of diarrhoea stool differ?
floating: fat? malabsorption?
blood/mucus: inflammation? cancer?
how does food history impact diarrhoea
takeaways: food poisoning BBQs: campylobacter rice: bacillus cereus poultry: salmonella shellfish: norovirus
what else can influence diarrhoea?
hobbies, fresh wateR/? swimming?
animals?
medications
what are some stool tests for diarrhoea
microscopy
culture
toxin detection
ova, cysts and parasites esp if been abroad
where is watery diarrhoea located
proximal small bowel
where is bloody, mucoid diarrhoea located
colon
watery diarrhoea: inflamm or non?
non-inflammatory
bloody/mucoid diarrhoea: inflamm or non?
inflamatory
in the UK, what are 50-70% of diarrhoea cases caused by?
viruses
traveller’s diarrhoea occurs when?
within 2w of arrival in new country