liver failure Flashcards
describe paracetamol poisoning
less common free radical damage to hepatocytes overloading paracetamol pathways sudden loss of liver function assess with blood sample rapid death from: -bleeding -encephalopathy liver usually recover given time
what causes chronic liver failure?
cirrhosis primary liver cancer secondary liver cancer -metastases -bowel tumour common as cells washed through portal system and embed in liver
what is cirrhosis?
mixed picture of damage, fibrosis and regeneration of liver structure
what is the aetiology of cirrhosis? (multifactorial)
alcohol primary biliary cirrhosis viral disease-chronic active hepatitis autoimmune chronic hepatitis haemochromatosis cystic fibrosis
what are the signs and symptoms of cirrhosis?
none liver inflamed/shrunk acute bleed -portal hypertension -oesophageal varices jaundice oedema & ascites encephalopathy spider naevi, palmar erythema
what are ascites?
high portal venous pressure
low plasma protein synthesis
how do oesophageal varices occur?
blood entering portal system has no exit as portal vein cannot communicate w/ hepatic vein
due to disordered portal triads in liver cirrhosis
blood engorges as passes through vessels and lower oesophagus
veins dilated and fragile
protrude into oesophageal lumen
-rupture -> catastrophic bleed
what is loss of synthetic function?
plasma proteins
-transporting proteins
-gamma globulin
clotting factors
what is loss of metabolic function?
drug metabolism
detoxification
conjugation of RBC breakdown products
what liver function tests are available?
hepatic cell enzyme levels -ALT, GGT -measures degree of inflammation not function -proportional to number of hepatic cells INR -most useful -synthesis of clotting factors
what is INR?
measures prothrombin time against a control prothrombin->thrombin normal = 1 if on warfarin 2-4 if not 1 significant dysfunction
what are the effects of liver failure?
fluid retention raised INR & prolonged bleeding portal hypertension -inability of GI blood to re-enter vena cava -oesophageal varices inability to remove waste/urea -encephalopathy build up of haem breakdown products- jaundice
what are the treatments for liver failure?
supportive -end stage disease -acute failure transplant -only cure artificial liver systems -MARS -some function restored
what analgesics can you give a px with hepatic disease?
paracetamol
co-codamol
NO NSAIDS
-bleeding risk
what antifungals can hepatic dx px not take?
miconazole
erythromycin
tetracycline
