liver failure Flashcards
What is jaundice?
Elevated levels of bilirubin in blood plasma
What blood concentration of bilirubin is: Normal
17μmol/L
What blood concentration of bilirubin is: Yellow sclera
> 30μmol/L
What blood concentration of bilirubin is: Yellow skin
> 34μmol/L
What is cholestasis and its relevance in jaundice?
Slow or cessation of bile flow. Is a cause of jaundice
What are some Pre-hepatic causes of jaundice?
Haemolytic anaemia, toxins, ineffective erythropoesis, large haematoma resorption
What is a pre-hepatic jaundice typically associated with?
Increased production of bilirubin
What are some intrahepatic causes of jaundice?
Gilberts syndrome (reduced BR uptake), Crigler-Najar syndrome (reduced BR conjugation), Dubin-Johnson and Rotor syndrome (reduced BR secretion), Sepsis, TPN, drugs, acute & chronic liver failure
What are some post-hepatic causes of jaundice?
Gallstones, tumours, obstructions and inflammation of ducts
What is the simple pathophysiology of liver failure?
Rate of hepatocyte generation < rate of hepatocyte death (combination of apoptosis and necrosis)
What are the classifications of acute liver failure?
Fulminant and Sub-Fulminant
What is Fulminant liver failure?
rapid onset of liver failure (<8wks), reduced synthetic function and encephalopathy with previously normal liver function
Sub-fulminant liver failure?
< 6 month onset
What is chronic liver failure?
Onset over years, marked cirrhosis
What is the most common toxin to cause acute LF in the western world?
Paracetamol overdose (behind amanita phalloides, bacillus cereus)
What is the most common cause of acute liver failure in the eastern world?
Inflammation (due to Hep B or E)
What process exclusive to females can induce acute liver failure?
Acute fatty liver of pregnancy (AFLP), HELLP syndrome (haemolysis, elevated liver enzy. Low platelets), hepatic infarction, Budd-Chiari syndrome and Hep E
Which common drug interactions can cause acute liver failure?
Amoxicillin+clavulanic acid, trimethoprim+sulphamethoxazole, rifampicin+isoniaizid
What single drugs can cause acute liver failure?
Isoniazid, NSAID’s, valproate
Name two metabolic diseases which can cause acute liver failure?
Wilsons disease, Reye’s syndrome
Name some vascular diseases which can cause acute liver failure?
Ischaemic hepatitis, post-OLTx, hepatic artery thrombosis, post arrest, VOD
Name all the broad causes of chronic liver failure (I ‘AD CINA - say it in a cockney accent)
Inflammation, Alcohol abuse, Drug side effects, Cardiovascular effects, Inherited disease, NASH, Autoimmunity
Explain the process of cirrhosis
Noxious factor -> necrosis -> enzyme leakage -> cytokines activate kupffner and granulocytes -> fibroblast proliferation and microfibroblast activation -> fibrosis -> cirrhosis -> inflammation -> fibrosis etc
Consequence of LF on: Production of clotting factors
coagulopathy and bleeding
Consequence of LF on: Protein synthesis
ascites
Consequence of LF on: Detoxification
encephalopathy and cerebral oedema
Consequence of LF on:Glycogen storage
hypoglycaemia
Consequence of LF on: Immunological function, globin production
susceptibility to infection
Consequence of LF on: Homeostasis
circulatory collapse, renal failure, MOF