Transcript PATHOPHYSIOLOGY -The liver.

PATHOPHYSIOLOGY
-The liver.
Anne Aspin 2010
Bile.
 Thick
greenish yellow fluid secreted by
liver cells.
 Alkaline.
 Emulsifies fats in the intestine.
 It stimulates peristalsis in the intestine,
acts as a natural aperient.
 Deodorant in faeces.
 During
fetal life, placenta is the principal
route to eliminate unconjugated bilirubin.
 In
newborn infants hepatic cells excrete
conjugated water soluble bilirubin into
biliary system and gastro intestinal tract
A guide to the liver.
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Located behind lower
ribs on the right side
of the abdomen.
 An adult- size of a
rugby ball.
 300 billion specialised
cells- well organised
intricate system of
bile ducts and blood
vessels.
 The
little bile ducts drain every bile cell
and join together like tributaries entering a
stream to form one main duct from each
lobe.
 The two ducts join to form the common
hepatic duct, this joins the duct from the
gall bladder (cystic duct), to form the
common bile duct. This joins the small
intestine through the Ampulla of Vater.
The gall bladder and its ducts.
Blood supply to and from the liver.
 Hepatic
artery- which divides into fine
branches –to the fine bile ducts.
 Portal vein carries nutrients from the
stomach and intestine to the liver (also
from spleen).
 Portal vein divides into fine branches- into
sinusoids.
 Blood leaves sinusoids via hepatic vein to
heart.
Functions of the liver.
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Breaks down fat to produce energy.
Amino acids broken down to form urea.
Detoxicate drugs.
Vit A synthesized to carotene.
Liver main heat producing organ.
Plasma proteins synthesized.
Tissue cells broken down – uric acid and urea.
Carbohydrate converted to fat for storage.
Functions (cont)
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Prothrombin and fibrinogen synthesized from
amino acids.
Antibodies and antitoxins are manufactured.
Heparin is manufactured.
Stores: Vit A and D, anti anaemic factor, iron
from diet, glucose stored as glycogen and back
to glucose in the presence of insulin.
Bile is formed.
Guess which one was on TPN?.
Extremely Low Birth Weight Infant
Less than 1000g, less than 27/40
 Susceptible to all complications of
prematurity
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 Thermoregulation
– high surface area to
body weight
 Hypoglycaemia – stress and low glycogen
stores
ELBW
and electrolytes –
PDA,IVH,CLD,BPD
Compromised renal function
– decreased GFR
– decreased ability to reabsorb bicarbonate
– inability to concentrate urine
 Fluids
Nutrition
 High
energy requirements for growth
 Heat loss raises energy need
 Trophic feeding stimulates gastro-intestinal
tract and prevent mucosal atrophy
 Prolonged TPN may result in cholestasis
and elevated triglyceride levels.
 Breast milk
Hyperbilirubinaemia
 Increased
production of bilirubin
transfusion, infection
 Decreased
activity of transferase enzyme
due to hypoxia,infection,hypothermia or
thyroid deficiency
Hyperbilirubinaemia (cont)
 Block
of transferase enzymes (drugs)
 Decreased
enzyme- prematurity
 Decreased
bilirubin uptake by liver cells
Kernicterus
 Occurs
when unconjugated bili crosses
blood-brain barrier staining basal ganglia,
pons and cerebellum
 Those
who do not die with kernicterus are
deaf, mental retardation and cerebral
palsy
Phototherapy
 Decreases
 Breaks
unconjugated bilirubin levels
down so water soluble, so can be
easily excreted
Hepatic complications in preterm
babies on TPN
 Cholestasis
7.4% - 84%
reported 1971 – baby 71days old,
cholestasis, bile duct proliferation, early
cirrhosis
 1st
 Early
feeding reduces above
 Increased biochemical test results of
damage, function and excretion
Prevention
 Early
enteral feeding
 Prevention of sepsis
 Cycling TPN
 Mucus fistula re-feeding
 Ursodeoxycholic acid
Differential diagnosis
 Jaundice
birth-24hrs
 Sepsis
 Haemorrhage
 Cytomegalovirus
 Rubella
 Congenital
toxoplasmosis
Jaundice day 2-3
 Physiological
jaundice
 Criggler Najjar syndrome
Jaundice after day 3
 Septicaemia
 Syphillis
 Toxoplasmosis
 Cytomegalovirus
Jaundice after one week
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Breast milk
Septicaemia
Congenital atresia of ducts
Hepatitis
Rubella
Herpes
Galactosaemia
Hypothermia
Haemolytic disease
Jaundice after one month
 Inssipated
bile syndrome
 TPN related cholestasis
 Cytomegalovirus
 Syphillis
 Toxoplasmosis
Biliary atresia.
What is biliary atresia?.
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Inflammation
develops within bile
ducts around time of
birth, either within
ducts inside or
outside of the liver.
 Bile ducts outside
liver – irreversible
damage preventing
bile flow.
Signs of biliary atresia.
 Seem
well, but white of the eyes are
yellow, yellowing of the skin.
 Yellow coloured urine.
 Pale stools.
 Bleeding –prolonged.
Investigations.
 Haematological
and liver function tests.
 Screening for infection and metabolic
causes.
 Ultrasound examination.
 Radionuclide studies.
 Percutaneous liver biopsy.
Always look for yellow pooh!!!
Treatment.
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Surgical operation
called a Kasai
procedure.
 Major surgery, very
sick babies.
Extrahepatic biliary atresia.
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The blocked duct is
removed.
 A single open duct is
then joined to a loop
of intestine.
Hepaticojejunostomy.
Post operation.
 IV
fluids.
 Pain relief.
 Antibiotics.
 Parents.
 Medications regime.
Medications.
antibiotics –to reduce risk of cholangitis.
 Vitamins A,D,E,K - due to poor bile flow
which reduces absorption of dietary fat
soluble vits.
 Phenobarbitone – given to increase bile
flow.
 Questran – improves liver function and
removes substances which cause the skin
to itch.
 IV
Medications (cont)
– excretion of excess fluid
which otherwise collects in the abdomen.
 Ursodeoxycholic acid – promotes the flow
of bile.
 Ranitidine – reduces stress induced
stomach irritation.
 Spironalactone
Some complications may occur.
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Cholangitis
Ascites
Low albumins
Portal hypertension
Itching
Cholangitis.
 An
infection of the bile ducts resulting in
inflammation.
 Pyrexia
 Increasing jaundice
 Further liver damage
 IV antibiotics.
Ascites
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An abnormal collection of fluid in the abdomen
around the organs.
May be associated with general oedema.
Protruding abdomen
Shiny, tense
Prominent veins
Rapid weight gain
Shortness of breath
Reduced appetite.
Complications of ascites
 Failure
to thrive and vomiting
 Infection
 Restricted movement
 Breathing difficulties.
Albumins.
 If
ascites persists, disease process has
affected the livers ability to make albumin.
 Diet will be assessed to reduce fluid and
salt intake.
 20% Albumin infusion.
Portal hypertension.
 High
blood pressure in the portal vein, the
main vein carrying blood from the gut to
the liver.
 Occurs due to scarring in the liver which
causes back pressure in the portal vein.
 This causes veins like varicose veins to
develop in the lining of the oesophagus,
stomach or intestine.
Portal hypertension
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Blockage of portal
vein –thrombus.
 Scarring in the liver
 Increased resistance
to blood leaving the
liver, due to
obstruction or heart
disease.
Portal hypertension (cont)
spleen – from back pressure,
effects breakdown of RBC as new are
made, when spleen enlarged it removes
more than it should – effects platelets
needed for blood clotting.
 Ascites –from back pressure on blood
vessels –forces fluid to leak out to around
surrounding organs.
 Prominent veins over abdomen.
 Enlarged
Portal hypertension (cont)
 Varices,
also known as collaterals. Thin
walled and can bleed.
 Bleeding causing tiredness,
breathlessness, pale appearance. Present
in vomit or stools.
 Diarrhoea, poor weight gain –the blood
vessels in the lining of the intestine swell
as blood flows under pressure, reduces
absorption of digested food.
Pruritis/itching.
 Occurs
with poor bile flow.
 Excessive amounts of bile acids.
 From mild , intermittent or severe.
 Palms, soles of feet, extremeties and
trunk.
 Medications for treatment.
Pruritis/itching (cont)
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Questran/ cholestyramine. Combines with bile
acids in the small intestine and reduces
reabsorption.
Phenobarbitone –helps liver to excrete the
substances thought to induce itching.
Rifampicin –significant relief from itching by
reducing harmful bile acids but increases the
amount of protective acids.
Sedatives –Vallergan.
Ursodeoxycholic acid –increases watery bile
salts to aid secretion.
Choledochal cyst.
– relating to bile
 Dochal – containing or receiving
 Cyst – fluid collection
 Chole
 Affects
ducts outside liver. Bile collects
inside dilated ducts – flow of bile impaired.
 Caused by ?malformation of bile duct
inutero.
Types of choledochal cyst.
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1:50,000
 3 x girls than boys
 These two types
cause pancreatitis.
Other types of choledochal cysts.
Signs and symptoms
 Jaundice,
 Persistant
or intermittent.
 Pale stools and dark urine
 Intermittent abdominal pain.
 Cholangitis, causing rigors.
 Peritonitis, if the cyst bursts or leaks.
 An abdominal swelling
Roux loop.
Complications
 Bleeding
 Infection
 Leakage
where ducts join to the bowel.
 Cholangitis
 Pancreatitis.
 Cancer of bile ducts later in life –rare.
Cystic fibrosis and liver disease.
 Liver
disease more likely to develop with
those babies who had meconium ileus as
an infant.
 Damage starts in the small bile ducts, bile
stickier than normal –blockage of ducts.
 Surrounding tissue then becomes
damaged and scarred –biliary fibrosis.
 Liver becomes hard and the blood flow
through more difficult.
examination – hepatomegaly,
splenomegaly.
 Portal hypertension
 Liver function tests
 Abdominal ultrasound
 Physical
Treatments
 Medications
 Nutrition
 Endoscopy
for varices
 Sclerotherapy of oesophageal varices
 Banding
 TIPS –radiological procedure which
reduces blood flow through varices
directing it through a channel created in
the liver.
Alagille Syndrome
 Biliary
hypoplasia in association with at
least two other anomalies in the body.
 1:100,000, boys = to girls.
 Severity differs with each baby
Biliary hypoplasia
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Ducts not formed properly so the bile flow is
poor causing liver dysfunction and sometimes
jaundice.
Typical facial features include prominent
forehead, deep set eyes and a small chin.
Cardiovascular – pulmonary artery stenosis,
from mild to severe symptoms.
Posterior Embrytoxon –accumulation of a
substance on inner aspect of cornea.
Butterfly notches of the spine.
Autoimmune liver diseases
 Caused
by body’s defence mechanism,
immune system malfunctioning and
attacking part of itself.
 Two types: autoimmune hepatitis and
autoimmune sclerosing cholangitis.
 Continuous
cell destruction results in
scarring of the liver leading to cirrhosis.
Symptoms
 Tiredness,
loss of appetite,spider-naevi,
nausea and vomiting, weight loss, itching,
fever, nose bleeds, jaundice, abdominal
pain, ascites,lower limb oedema, irritability.
 Treatment
with immunosuppresive drugs.
Gilbert’s disease.
 A liver
condition which is mild in nature.
 Intermittent jaundice, no abnormality of
liver function.
 Males more than females.
 Abdominal discomfort, lethargy, malaise.
 May be triggered by infection, overexertion
and fasting.
Feeding baby’s with liver disease.
Nutrition
 The
liver plays an important role in good
nutrition and growth.
 It produces bile which helps to absorb fat
in the diet
 It converts the nutrients in the diet into
energy and substances needed for growth
and normal body functions.
 Babies
drink large quantities of milk, as
they do not digest nutrients they still feel
hungry.
 Poor nutrition leads to poor growth, lack of
energy and increased risk of infection.
 Need to drink special formula. Not normal
formula which has long chained
triglycerides and needs a good bile flow for
absorption.
Milks
 Medium
chain triglycerides found in
Pregestimil, Peptijunior and Neocate.
 These milks can be taken and fully
absorbed as they do not need bile for
absorption of the fat.
 Weaning between 4-6 months.
 Supplementary vitamins.
Tube feeding
 This
is not unusual.
 Pressure to get nutrition into a baby that
will not feed.
 Need to get full requirements as
mentioned before.
 Continuous overnight feeding, small bolus’
by day
 Gastrostomy –only if absolutely necessary.
Thank you
Time to go home.
References
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Bassett M, Murray K (2008). Biliary atresia: recent progress. Journal
of Clinical Gastroenterology. 42 (6) : 720 – 729
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Cincinnati Childrens Hospital Medical Center (2009). Liver diseases
and treatments. Biliary atresia.
www.cincinnatichildrens.org/suc/alpha/1/liver
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Manning D, Todd P, Maxwell M et al (2007). Prospective surveillance
study of severe hyperbilirubinaemia in the newborn in the UK and
Ireland. Archives of Disease in Childhood. Fetal Neonatal Edition.
92 : F342 - F346

Schwarz S (2009). Biliary atresia: eMedicine Pediatrics.
Emedicine.medscape.com

Smitherman H, Stark A, Bhutani V (2006). Early recognition of
neonatal hyperbilirubinaemia and its emergent management.
Seminars in Fetal Neonatal Medicine. 11 : 214 - 224