Liver Failure Flashcards
what is acute liver failure?
sudden loss of liver function
what can cause acute failure?
paracetamol poisoning
what can acute liver failure result in?
rapid death from bleeding or encephalopathy
what is the only option to treat acute liver failure
transplant
what are the different types of chronic liver failure?
cirrhosis, primary liver cancer, secondary liver cancer (metastases)
what is cirrhosis?
mixed picture of damage, fibrosis, and regeneration of liver structure
what is the multifactorial aetiology of cirrhosis?
alcohol, primary biliary cirrhosis, viral disease (chronic active hepatitis), autoimmune chronic hepatitis, haemachromatosis, cystic fibrosis
what are the signs and symptoms of cirrhosis?
non, acute bleed, jaundice, oedema and ascites (abdominal fluid), encephalopathy, spider naevi, palmar erythema
what is spider naevi?
small prominent arterioles developing near the skin, enlarged and can produce centre arteriole
what is palmar erythema?
pattern of pale palm surrounded by erythema around hand margins
what is palmar erythema caused by?
high oestrogen levels caused by reduced metabolism
what is ascites caused by?
high portal venous pressure, low plasma protein synthesis (lower oncotic pressure)
what is the cause of oesophageal varices?
blood which enters the portal system in the liver cannot exit as the portal vein cannot communicate with hepatic vein due to portal triad distortion in liver cirrhosis, instead the blood passes through to lower oesophagus forcing the veins to dilate and become fragile. The veins can protrude into the oesophageal lumen which is then easy to rupture which food and lead to bleed
what are the two components that are lost in liver failure?
synthetic function and metabolic function
what is the synthetic function of the liver which is lost to liver failure?
production of plasma proteins (transporting and gamma globulins) and production of clotting factors
what is the metabolic function of the liver which is lost to liver failure?
drug metabolism, detoxification, conjugation of RBC breakdown products
what are the tests used for liver function?
hepatic cell enzyme levels, INR
what are the enzymes which are looked for in hepatic cell enzyme level tests?
ALT, GGT (raised in liver inflammation and fall in end stage liver disease)
what does INR measure?
prothrombin to thrombin rate
what is the normal value for INR
1
what is the warfarin INR value?
2-4
what does it mean if INR is not 1
there is significant liver synthetic dysfunction
what is the effect of liver failure?
ascites (fluid retention), raised INR and prolonged bleeding, portal hypertension, inability to remove waste urea, build up of haem breakdown products (jaundice)
what is portal hypertension?
inability of GI blood to re-enter the vena cava
what does portal hypertension lead to?
oesophageal vein dilation (varices)
what is the treatment for liver failure?
supportive for end stage and acute failure, transplantation, artificial liver systems
what must the patient take after getting a liver transplant?
immunosuppressants
in what situation is liver transplant not an option?
when the patient is an alcoholic - they must be off alcohol for a substantial amount of time before getting a transplant
what is the result of end stage liver disease?
clotting disorders, abnormal drug metabolism
what are the metabolic consequences with liver failure that dentists should be aware of?
prolonged sedative effect, avoid certain antifungals, discuss with physician whether to reduce drug doses, avoid ibuprofen and other NSAIDs - paracetamol is safest
what synthetic consequences of liver failure should the dentist be aware of?
reduced clotting factor synthesis so bleeding tendency, reduced plasma transport protein synthesis so drug doses need reduced, reduced gamma globulin synthesis so more prone to infections
what is the option which helps with reduced clotting factor synthesis?
fresh frozen plasma given to the patient
