Week 11- Liver Failure Flashcards
What is the main pathophysiological characteristic of jaundice
High levels of bilirubin
What is the normal level of plasma BR?
17 micro ml
What happens when BR exceeds 30 micro ml?
Yellow sclera and mucous membranes
What happens when BR exceeds 34 micro ml?
Yellow skin
What is cholestasis?
Slow bile flow/ cessation of bile flow
Does jaundice always indicate cholestasis?
No
What are pre hepatic causes of jaundice?
Haemolysis, ineffective erythropoiesis, massive transfusion etc reducing bile production
What are intra hepatic causes of jaundice?
Problems with conjugation of bilirubin, decreased uptake, decreased secretion, reduced outflow (cholestasis), liver failure
What are post hepatic causes of jaundice?
Gallstones, tumors etc reducing extra hepatic outflow
What is liver disease from pathophysiological point of view?
Hepatocyte death rate > hepatocyte regeneration
How does cell death occur in liver failure?
Can apoptosis or necrosis (or a combination)
How serious is liver failure?
Very serious, can lead to multiple organ failure and coma
What are the 2 types of acute liver failure? Define them
Fulminant hepatic failure= rapid development in less than 8 weeks of severe acute liver injury, impaired synthetic function, encephalopathy, previously normal liver
Sub fulminant= same but develops in less than 6 monthds
What is chronic liver failure?
Over years, cirrhosis
What are the 2 common causes of liver failure and where are they most common?
Toxins (western world): Paracetamol, bacillus cereus
Inflammation (eastern world): Hep E (India) and chronic Hep B exacerbations (Hong Kong)
What are some other uncommon causes of acute liver failure?
Disease of pregnancy
Idiosyncratic drug reactions
Vascular disease
Metabolic disease
What are causes of chronic liver failure?
Inflammation Alcohol abuse Side effects of drugs Cardiovascular disease Inherited disease
What is the consequence during hepatocyte failure of lack of production of clotting factors?
Coagulopathy and bleeding
What is the consequence during hepatocyte failure of lack of protein synthesis?
Ascites
What is the consequence during hepatocyte failure of lack of detoxification?
Encephalopathy and cerebral oedema
What is the consequence during hepatocyte failure of lack of glycogen storage?
Hypoglycaemia
What is the consequence during hepatocyte failure of lack of immunological function and globulin production?
Increased susceptibility to infection
What is the consequence during hepatocyte failure of lack of maintenance of homeostasis?
Circulatory collapse, renal failure
Why do ascites arise?
Reduced albumin
What are the consequences of cholestasis pathophysiologically?
Aggravates bleeding tendency, reduced bile salts results in reduced absorption of vit K and its carboxylation
What are the clinical consequences of cholestasis?
Increased BR leads to jaundice Pruritus (itching) Cholesterol deposition Malabsorption Cholangitis
What condition associated with blood cell count occurs due to liver failure and why?
Thrombocytpenia due to splenomegaly
What does exudative enteropathy in liver failure lead to?
Increased ascites (loss of albumin from plasma) Increased liberation of ammonia (toxic to the brain)
What makes ascites worse during liver failure?
Reduced lymphatic flow
What are pre hepatic causes of portal hypertension?
PV thrombosis
What are intra hepatic causes of portal hypertension?
Presinusoidal= chronic hepatitis, granulomas Sinusoidal= acute hepatitis, alcohol, fatty liver, toxins Postsinusoidal= venous occlusive disease of venules and small veins
What are consequences of portal hypertension?
Malabsorption
Splenomegaly- anaemia and thrombocytopenia
Vasodilators- glucagon, prostacyclins etc lead to hyperperfusion of abdominal organs and varices
Encephalopathy- toxins from the intestine get into the CNS
Varices- thin walled collateral vessels and reduced clotting factors w thrombocytopenia lead to bleeding
What is hepatic encephalopathy?
Apathy, memory gaps, tremor and liver coma
What is clinically observable in someone with hepatic encephalopathy?
Hyperammonaemia (liver cant NH3 or NH4+ to ammonia)
Hypokalaemia
Toxins (bypass the liver)
False transmitters
How is the severity of liver failure measured?
Via the Child- Pugh score
What total bilirubin level gives 1/2/3 points on the Child- Pugh score?
1: <34
2: 35-51
3: >51
What serum bilirubin level gives 1/2/3 points on the Child- Pugh score?
1: >35
2: 28-35
3: <28
What INR level gives 1/2/3 points on the Child- Pugh score?
1: <1.7
2: 1.71- 2.3
3: >2.3
What ascites level gives 1/2/3 points on the Child- Pugh score?
1: none
2: slight/surpressed with medication
3: moderate despite diuretics/refractory
What hepatic encephalopathy level gives 1/2/3 points on the Child- Pugh score?
1: none
2: grade I-II
3: grade III-IV
How is the Child Pugh scale used?
Class A: 5-6 points (expectancy of 15-20 yrs)
Class B: 7-9 points (transplant candidate)
Class C: 10-15 points (life expectancy 1-3 months)
What treatment is offered to those with liver failure for encephalopathy?
Reduce protein intake
Phosphate enemas/lactulose
What treatment is offered to those with liver failure for hypoglycaemia?
Infusion 10-50% dextrose
What treatment is offered to those with liver failure for hypoglycalcaemia?
10ml 10% gluconate
What treatment is offered to those with liver failure for renal failure?
Haemofiltration
What treatment is offered to those with liver failure for respiratory failure?
Ventilation
What treatment is offered to those with liver failure for hypotension?
Albumin and vasoconstrictors
What treatment is offered to those with liver failure for infection?
Frequent cultures
Antibiotics
What treatment is offered to those with liver failure for bleeding?
Vit K
FFP
Platelets
What are causes of death from liver failure?
Bacterial and fungal infections Circulatory instability Cerebral oedema Renal failure Respiratory failure Acid/base or electrolyte disturbance Coagulopathy
What are some liver support devices used to treat liver failure?
Artficial albumin exchange system- based on selective removal of albumin bound toxins from blood
Bioartificial- hepatocytes in culture
Hepatocyte transplantation
What are the main indications for liver transplantation
Cirrhosis
Cancer
Cholestatic disease
What is required lifelong after liver transplation
Immunosurpression
What is the 5 year survival rate of liver transplants?
60-80% and no recurrence of disease