liver Flashcards
liver failure: define liver failure, identify main types and underlying pathophysiology, recall aetiology, explain the clinical features and complications of liver failure and recall possible treatments
commonest causes of liver disease in developed world
alcohol, non-alcoholic fatty liver disease
commonest causes of liver disease in developing world
chronic viral hep B or C
symptoms of liver disease
asymptomatic, with general lethargy, anorexia, malaise, pruritus (itchy skin), right upper quadrant pain
symptoms of progressive liver failure
peripheral swelling, abdominal bloating, bruising, vomiting of blood, confusion and somnolence
common signs of liver disease
jaundice; reduced ability to metabolise oestrogens: spider naevi, loss of body hair, gynaecomastia, testicular atrophy, palmar erythema
other signs of liver disease
xanthelasma (yellowish deposit of cholesterol underneath skin - normally around eyelids), finger clubbing, pruritus, Dupuytren’s contracture, ascites and dilated abdominal veins, hepatomegaly, hepatosplenomegaly, caput medusa (severe portal hypertension), oedema, weight loss and loss of musculature, bruising, hepatic encephalopathy, fetor hepaticus (musty sweet breath), hepatic flap (coarse hand tremor)
what 3 categoreis are signs split into
compensated (liver function compensated), general and decompensated (loss of function)
what is the final common pathway for liver disease
cirrhosis (confirmed by biopsy)
what is cirrhosis characterised by
necrosis of liver cells, followed by progressive fibrosis and nodule formation
what does cirrhosis lead to
impairment of function and gross distortion of architecture, leading to portal hypertension and deterioration of liver function
what does cirrhosis develop in response to
chronic liver injury
2 types of cirrhosis
micronodular, macronodular
feature of micronodular cirrhosis
uniform, small nodules up to 3mm diameter
2 causes of micronodular cirrhosis
ongoing alcohol damage, biliary tract disease
feature of macronodular cirrhosis
nodules of variable size
cause of macronodular cirrhosis
chronic viral hepatitis
definition of acute liver failure
severe hepatic dysfunction occuring within 6 months of onset of liver disease, with clinical manifestation of hepatic encephalopathy (brain) or coagulopathy (blood), caused by massive loss of hepatocytes
3 classifications of acute liver failure
hyperacute: encephalopathy occurs within 7 days of jaundice onset; acute: encephalopathy occurs after 8-28 days of jaundice onset; subacute: encephalopathy occurs 5-12 weeks after jaundice onset
divisions of primary features of hepatic failure after jaundice
CNS complications, coagulopathy, renal failure, sepsis, cardiovascular complications, metabolic complications
sepsis and liver failure
90% with bacteria, 32% with fungi; infection within 3 days of admission; fever and leucoytosis absent; reduced in acute liver failure by prophylactic IV antibiotic therapy
cardiovascular: what does acute hepatic failure cause a reduction in
peripheral resistance, requiring reflex increase in cardiac output to maintain pressure
cardiovascular outcome of acute liver failure in pre-existing heart disease
cardiac failure, hypotension
2 common metabolic signs in liver failure
hypoglycaemia, hypoxia
what induces cerebral oedema in hepatic encephalopathy caused by liver failure
accumulation of toxins from gut - leads to coma
what is hepatorenal syndrome
occurence of unexplained renal failure in patients with liver disease/patients undergoing surgery for biliary tract obstruction (kidneys are morphologically normal)
what is renal failure due to in hepatorenal syndrome
reduced renal blood flow (more in cortex) due to cortical vasoconstriction, resulting from endotoxin (vasoactive) cleared in liver
when does resolution only occur for hepatorenal syndrome
dramatic improvement in liver function (transplant), otherwise 95% fatality
what coagulation factors does liver synthesise
I, II, V, VII, IX, X
what coagulation factors are affected first in liver disease
vitamin K-dependent factors (II, VII, IX, X) - liver absorbs vitamin K; VII is earliest as has shortest half-life; fibrinogen (I) synthesis only affected in severe disease
what does the liver inhibit in its role with coagulation
fibrinolysis/coagulation (synthesises plasma anticoagulant proteins C, S and antithrombin III)
role of liver in clearing activated clotting factors
fibrin, tPA removed from circulation by reticuloendothelial system
what does impairment in any coagulation-associated liver role lead to
bleeding, oozing at venepuncture sites from excessive fibrinolysis, bruising
when does chronic liver failure occure
when there is a deterioration in liver function superimposed on chronic liver disease causing decompensation
pathological processes causing potentially rapid acute deterioration
underlying disease process, different process undermining functional reserve of liver (e.g. infection, haemorrhage, electrolyte imbalance)
