Liver Flashcards
What is the definition of acute liver failure?
Hepatic encephalopathy and deranged clotting (INR >1.5)
In a patient with a previously healthy liver
Otherwise it’s acute-on-chronic liver failure
What is the definition of chronic liver failure?
Development of abnormal fibrotic tissue and destruction of hepatic architecture
Leading to physiological dysfunction
For at least six months
What are the systemic manifestations of portal hypertension?
Varices
Splenomegaly
Ascites
Hydrothorax
Hepatorenal syndrome
Hepatopulmonary syndrome
Thrombocytopenia
What are the causes of portal hypertension?
Pre-hepatic
Splenic vein thrombosis
Portal vein thrombosis
Intra-hepatic
Alcoholic liver disease (cirrhosis)
Non-alcoholic fatty liver disease (NASH)
Viral hepatitis (B or C)
Primary biliary cirrhosis
Idiopathic liver fibrosis
Polycystic liver disease
Wilson’s disease
Haemochromatosis
Sarcoidosis
Drugs (methotrexate)
Post-hepatic
Budd-Chiari syndrome
Right heart failure
Pericarditis
Tamponade
Vena cava obstruction
What types of cell are found in the liver?
Hepatocytes - metabolism and transport
Cholangiocytes - bile production
Kupffer cells - phagocytosis of iron from senescent RBCs
Endothelial cells - highly fenestrated to facilitate transport
Stellate cells - regulate blood flow and store vitamin A
Note that there are no membranes in the sinusoidal spaces, meaning that any central venous pressure can back straight up into the interstitium of the liver itself.
What are the contraindications to TIPS?
Absolute
Heart failure
Severe tricuspid regurgitation
Severe pulmonary hypertension (>45 mmHg)
Hepatic cysts
Severe uncontrolled sepsis
Obstructive biliary pathology
Relative
Hepatic vein obstruction
Portal vein thrombosis
Hepatocellular carcinoma
Severe coagulopathy
Severe thrombocytopenia (<20)
Encephalopathy
Moderate pulmonary hypertension
Why should liver patients have reduced doses of thiopentone?
Reduced plasma proteins result in reduced protein binding of thiopentone
This results in an increased unbound fraction of the drug and increased clinical effect
The same applies to alfentanil - less protein binding by alpha1-acid glycoprotein.
Why should liver patients have reduced doses of rocuronium?
Rocuronium undergoes significant hepatobiliary excretion, which is impaired in liver disease
This means the elimination phase for rocuronium is increased, resulting in longer duration of action
What are the cardiovascular effects of liver disease?
Hyperdynamic circulation
Increased cardiac output
Reduced systemic vascular resistance
Cardiomyopathy (due to haemosiderosis and alcohol)
Ischaemic heart disease (due to other comorbidities)
What are the respiratory effects of liver disease?
Pleural effusions
Reduced FRC and atelectasis due to splinting from ascites
Increased risk of aspiration (due to ascites, reflux)
Intrapulmonary arteriovenous shunting
Orthodeoxia (shortness of breath when sat up)
Portopulmonary hypertension (rare)
What are the haematological effects of liver disease?
Anaemia (bleeding, haemolysis, malnutrition)
Thrombocytopenia
Hypofibrinogenaemia
Reduced vitamin K dependent clotting factors (2, 7, 9, 10)
What are the renal effects of liver disease?
Secondary hyperaldosteronism
Water retention
Hyponatraemia
Peripheral oedema
Renal hypoperfusion due to vasodilatation
Hepatorenal syndrome*
*A combination of hypoperfusion, portal hypertension, intra-abdominal hypertension and build up of nephrotoxins
What are the grades of hepatic encephalopathy?
0 = Alert and orientated
1 = Drowsy but orientated (incoordination, apraxia, tremor)
2 = Drowsy and disorientated (asterixis, dysarthria, ataxia)
3 = Agitated and aggressive (muscle rigidity, Babinski +, hyper-reflexia)
4 = Unresponsive (Decerebrate)
What signs and symptoms may be found on history and examination of a patient with liver disease?
Remember they may be completely asymptomatic!
Leuconychia
Palmar erythema
Dupytren’s contracture
Spider naevi
Telangactasia
Bruising
Oedema
Parotid swelling
Gynaecomastia
Hepatomegaly
Testicular atrophy
Encephalopathy
Specific to portal hypertension
Ascites
Splenomegaly
Caput medusae
Due to malnutrition
Muscle wasting
Cachexia
Glossitis
How can liver disease be risk stratified?
The most commonly used scoring systems for chronic liver disease are:
Child-Turcotte-Pugh score
Model for end-stage liver disease or MELD score
The Mayo Clinical mortality calculator
VOCAL-Penn model
