Transcript HEPATIC FAILURE - Dr. Mehdi Hasan Mumtaz

HEPATIC FAILURE
DR.M.H.Mumtaz
Topics
• Anatomy
• Histology
• Liver Functions
• Liver Function Tests
• Liver Failure
• Management in ICU
ANATOMY
 Wt
. 1.8 - 2 Kg
 Blood supply = 25 % CO

Topography = 2 Lobes subdivided into lobules

Rt Lobe
=have 2 suspended Lobes
Caudate Lobe
quadrate Lobe
Liver Blood Flow
= 1100 -1800 ml / min 25 % CO
 Hepatic artery = 30 – 40 %
= O2 supply = 40 - 55 %
= Saturation = 98 %
= flow = sphincteric mechanism
 Total
Liver Blood Flow
 Hepatic
Portal vein
= 70 % B. flow
=50 - 60 % O2 supply
= po2 = 50 mm Hg
= blood velocity = 9 cm/sec
 Hepatic arterio-venous reciprocity
Liver Blood Flow
Blood Flow
1.
2.
3.
4.
5.
PCO2
Hepatitis
Supine Posture
Food
Drugs
• Beta stimulants
• Phenobarbitone
• Enzyme inducers
Blood Flow
1.
2.
3.
4.
5.
6.
IPPV + PEEP
Surgery
PCO2 , Hypoxia
Upright posture
Cirrhosis
Drugs
• alpha stimulants
• Beta blockers
• Ganglion blockers
• Ranitidine
• Pitressin
• Anaesthetics
Histology
zone 1 - receives blood with
zone 2 - intermediate
zone 3 - receives blood with
spo2
spo2
Important Liver Functions
A.
Carbohydrate Metabolism
1. Glycogen synthesis
2. Glycogenolysis
3. Gluconeogenesis
Important Liver Functions
B.
Lipid Metabolism
1.
2.
3.
Synthesis of Lipoproteins
• Phospholipids
• Cholesterol
• Endogenous Triglycerides
Excretion of breakdown products of
cholesterol
Ketone synthesis
Important Liver Functions
C.
D.
E.
F.
G.
H.
Protein Synthesis
Vitamin .D metabolism
Vitamin A, B, B12. stored in liver
Iron store
Excretion & Detoxication
Reticuloendothelial function
Liver Function Tests
A.
Static Tests
B.
Dynamic Tests
Liver Function (Static )Tests

Liver cell damage
1.
2.

Liver cell dysfunction
1.
2.
3.

Serum Proteins
Coagulation factors - PT, APTT
Serum Bilirubin
Biliary Tract obstruction
1.
2.
3.

Transaminases
Lactate dehydrogenase
Alkaline Phosphatase
Gama-glutamyl Transferase
Bilirubin
Tests Indicating aetiology
ROLE OF VIT K
LIVER ----------VIT. K
WARFARIN -------gamma glutamyl carboxylase
ADDS
carboxyl group to glutamic acid residue
ON
Factors, 2nd,7th,9th & 10th. Proteins S,C,&Z
( activation)
PROTHROMBIN TIME(PT)
HEPARINES
ANTITHROMBINS(SERINE PROTEASE INHIBITOR)
DEGRADE
THROMBIN,F9a, F10a,F12a ( serine proteins)
HEPARIN
increase adhesion of antithrombins to factors
Functional ( Dynamic) Tests
1.
Impaired Lactate clearance (lactate level)
2.
Clearance of organic substances
•
3.
Anionic dye – Indocyanine green (ICG)
Formation of metabolites
•
Monoethylglycinxylidid from lidocain (MEGX)
Topology of Liver Damage
1.
Diffuse Parenchymal damage
2.
Periportal damage
3.
Pericentral damage
Response to injury
1.
2.
3.
4.
5.
6.
Necrosis
Degeneration
Steatosis
Regeneration
Inflammation
Fibrosis
ETIOLOGICAL FACTORS
1.
NON . INFECTIOUS
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2.
Alcohol
Drug related
Reyes’ Syndrome
Pregnancy
INFECTIOUS DAMAGE
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Fungal
Protozoal
Malaria
Parasites
Liver abscess
Aetiology
3. Viral Infections
a. Systemic Viral infection
•
Infectious mononucleosis
•
cytomegalovirus
•
Herpes virus
•
In children ( rubella, adenovirus enterovirus)
Aetiology, 3. Viral infections
b. Hepatotropic Viruses
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Hepatitis A virus (HAV)
Hepatitis B virus (HBV)
Hepatitis C virus (HCV)
Delta Hepatitis virus (HDV)
Hepatitis E virus ( HEV )
Others – ( F,G…. ? )
4. Inborn Errors of metabolism
• Primary Haemochromatosis
• Wilsons’ Disease
• Alpha – 1 – Antitrypsin deficiency
5. Tumours
• Benign
• Malignant
LIVER FAILURE MANIFESTATIONS
a.
Hepatic Manifestations
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•
b.
Jaundice
Coagulopathy
Extrahepatic Manifestations
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Encephalopathy
Hepato-renal Syndrome
Susceptibility to infections
MANAGEMENT IN ICU
 General
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Intensive Care
Enteral nutrition
Stress ulcer prophylaxis
Glucose Homeostasis
Antibiotic prophylaxis / SDD
Control Intracranial Hypertension
Albumen
Vasopressor for HRS
MANAGEMENT
 Specific
Therapy- Antidote
 Monitoring
by. PDR – ICG
 Extracorporeal
 Liver
Support
Transplant
Hepatic Encephalopathy
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
Toxic Metabolites
ammonia,glutamine
^ ICP
Ippv,Mannitol,Hypothermia
Hypertonic saline
Vasopressors--caution
Hepatorenal Syndrome
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1, Marked renal vasoconstriction
RBF decreased
GFR decreased
2,Absence of histological changes
3,Preserved tubular renal function
HRS Pathogenesis
Portal hypertension/Liver failure
1, Increased level of ; NO, CO.
2, Spanchnic arterial vasodilation
3,Low effective circulating volume
4, Activation of systemic endogenous
vasoconstrictors
5, Svere renal vasoconstriction
HRS Diagnostic criteria
 Major
criteria
CHF +Portal hypertension
Low GFR
Absence-shock,infection,drug
dehydration
No improovement after,removal of
diuretics, pv expansion
Proteinurea <500mg/dl
HRS Diagnostic criteria
 Minor
criteria
Urine volume<500ml/d
Urine sod.excretion<10mmol/l
urine osmolality/plasma osm>1
No finding in urine sediment
Natremia <130mmol/l
All major criteria +a few minor to support
HRS
TYPES
Type 1, Type 2
Rapidly progressive---RF with out rapidly
progressive
Acute r.failure-------------Refractory ascites
HRS
Precipitating events
spontaneus bacterial peritonitis
paracentesis without plasma expan
GIT haemorrhage
Severe acute alcoholic hepatitis
Unknown
HRS THERAPY
TIPS
(transjugular intravenous portosystamic s.)
+
Albumin,vasoconstrictors
MARS
(molecular adsorbant recycling system)
New therapies -HRS
Albumin+trlipressin
Albumin+Midodrine+octreotide
Albumin+Noradrenaline
Extracorporeal Liver Support