Liver, biliary and pancreatic disease Flashcards
Which strain of Ecoli is thought to be the most severe form? (Produces shigatoxin)
EO157
An isolated rise in serum bilirubin with otherwise normal liver biochemistry is likely to be due to what?
Inherited defect in bilirubin metabolism - Gilbert’s disease
Haemolysis
Ineffective erythropoiesis
What is the overall cause of high aminotransferases (AST, ALT)?
Liver cell damage e.g. acute hepatitis
What can high levels of AST (aspartate aminotransferase) be seen in other than liver injury?
Myocardial infarction/ skeletal muscle damage. Is present in both heart and skeletal muscle as well as liver
Which aminotransferase is a more specific measure of injury to the liver (ALT/AST)?
ALT
Raised serum concentrations of alkaline phosphatase is seen in what?
Cholestasis (bile flow impaired)
Can also be increased in pregnancy, osteomalacia and growing children (as is also derived from placenta and bone)
Gamma-GT serum concentration rises in what?
Alcohol abuse
Cholestasis (in parallel with alkaline phosphatase)
Why may a prolonged prothrombin time occur in biliary obstruction?
Low concentration of bile salts (emulsify) results in poor absorption of vitamin K, which is essential - key in synthesising blood clotting factors inc. prothrombin
What are the 4 main functions of the liver?
- Glucose and fat metabolism
- Detoxification and excretion
- Protein synthesis (albumin, clotting factors)
- Defence against infection (R-E system)
Name some causes of acute liver failure
Viruses (A, B, EBV), drugs, alcohol, vascular, obstruction, congestion
Name some causes of chronic liver failure
Alcohol, virus (B,C), autoimmune, metabolic (iron, copper)
What is the term given to iron overload, and when is it most commonly seen?
Haemachromatosis
Seen in those with regular blood transfusions. Iron chelation is required
How does acute liver injury present?
Malaise, nausea, anorexia, jaundice
How does chronic liver injury present?
Ascites, oedema, haematemesis, melaena (varices), malaise, anorexia, wasting, easy bruising, itching, hepatomegaly, abnormal LFT’s
What serum LFT’s give a relatively good index of liver function?
Serum bilirubin, serum albumin, prothrombin time
What enzyme in the liver conjugates bilirubin?
Glucuronyl transferase
What is Gilbert’s disease, and what causes it?
Congenital hyperbilirubinaemia, due to reduced glucuronyl transferase and therefore reduced conjugation of bilirubin –> High levels of unconjugated bilirubin build up. Often is asyptomatic but can appear jaundiced
What type of jaundice is seen in haemolysis, and how would LFT’s appear?
Unconjugated bilirubin causes. All LFT’s would be normal other than increased unconjugated bilirubin
How do the clinical symptoms differ in unconjugated jaundice and conjugated jaundice.
Unconjugated - jaundice, normal LFT
Conjugated - pale stool, dark urine, may itch (pruritis), abnormal LFT
Give some causes of hepatic jaundice?
Hepatitis (viral, drug, immune, alcohol), ischaemia, neoplasm, CCF
Give some causes of post hepatic jaundice?
Gallstones in bile duct, Mirizzi syndrome, stricture of CBD (malignant, ischaemic, inflammatory), blocked stent
What is Mirizzi’s syndrome?
Gallstone becomes embedded in cystic duct or neck of gallbladder and compresses CBD or hepatic duct
What are the two types of gallstone and how are they formed?
a) Cholesterol (70%) - cholesterol is held in solution by bile salts. So if excess cholesterol or reduced bile salt, they are formed
b) Pigment (30%) - consist of bilirubin polymers so are seen in chronic haemolysis and cirrhosis
What are the risk factors for gallbladder formation?
Fat, female, fertile
What is the management for a gallstone in both the gallbladder and bile duct if symptomatic?
Gall bladder = Laproscopic cholecystectomy
Bile duct = ERCP (endoscopic retrograde cholangio-pancreatography)
What is the main cause for acute liver failure?
Drug induced liver injury (DILI)
Drugs that are the possible cause of liver injury?
Antibiotics, CNS drugs, immunosuppressants, analgesics, GI drugs, dietary supplement
What enzyme in the body converts the reactive toxic paracetamol intermediate to a stable metabolite?
Glutathione transferase
What drug is used to increase the availability of glutathione transferase in a paracetamol overdose?
N-acetyl-cysteine (NAC)
What factors indicate a poor prognosis in paracetamol overdose and potential requirement for transplant?
- Late presentation (over 24 hours)
- Acidosis
- Prothrombin time > 70 sec
- Serum creatinine >=300mmol/l
What is melaena and what causes it?
Black tar like faeces associated with upper gastrointestinal bleeding
What is the most common cause of ascites?
Chronic liver disease (cirrhosis)
What is ascites?
Build up of fluid in peritoneal cavity
Outline pathogenesis of ascites
Nitric oxides from liver damage (cirrhosis) cause peripheral arterial vasodilation. Sympathetic nervous system, and renin angiotensin system try to compensate for this and increase secretion of NA, as well as aldosterone and vasopressin. Salt and water retention.
The resulting oedema is localised in the peritoneal cavity due to the portal hypertension caused by the cirrhosis. Low serum albumin also contributes
What is the management for ascites?
- Diuretics - begin spironolactone and move to furosemide. Must be careful to not remove too much fluid too quickly as transfer of fluid from ascitic to vascular compartment only 700ml/day. If do too fast will get hypokalaemia and encephalopathy
- Paracentesis
Give 3 causes of portal hypertension?
- Cirrhosis
- Fibrosis
- Portal thrombosis
What are the consequences of portal hypertension?
Increased hepatic resistance and therefore increased splanchic blood flow means that varices form (oesophageal or gastric) and splenomegaly may occur
What are the main sites of infection for liver patients?
SBP (ascites), septicaemia, pneumonia, skin (cellulitis), UTI
Cirrhotic patient with ascites BP and sats start to fall, general malaise. What test would be done, and what is the significance of this test being positive?
Diagnostic aspiration. Neutrophil count of 250 or over suggests spontaneous bacterial peritonitis and empirical antibiotic therapy given
What bacteria is the most common cause of SBP?
E.coli
Name 4 key consequences of liver dysfunction
- Malnutrition
- Coagulopathy - vitamin K deficiency
- Endocrine changes (gynaecomastia, impotence, amenorrhoea)
- Hypoglycaemia
What are the main causes of chronic liver disease?
- Alcohol
- NAFLD (Non alcoholic steatohepatitis)
- Viral (B,C)
- Autoimmune
- Metabolic
- Vascular
What is NASH commonly associated with?
Obesity, type 2 diabetes, hypertension, hyperlipidaemia
Autoimmune hepatitis is commonly seen in what patients?
Young and middle aged women
How will a patient with autoimmune hepatitis present?
Chronic liver disease signs: Palmar erythema, spider naevi, hepatosplenomegaly and jaundice
or anorexia, malaise, nausea and fatigue.
40% will present with acute hepatitis
What is the treatment for a patient with autoimmune hepatitis?
Prednisolone +- azathioprine
AMA (anti mitochondrial antibody) will be increased in?
Primary biliary cirrhosis and other autoimmune liver conditions (AIH, sclerosing cholangitis)
Name 3 autoimmune causes of chronic liver disease.
- Autoimmune hepatitis
- Primary biliary cirrhosis
- Sclerosing cholangitis
What does ASMA stand for and what is it raised in?
Anti-smooth muscle antibody
Raised in autoimmune condition
How does primary biliary cirrhosis present?
- Asymptomatic lab abnormalities
- Itching +- fatigue
- Variceal bleeding
- Possibly dry eyes and joint pain
How do varices occur and what are they?
Cirrhosis leads to portal hypertension in the liver, and the rerouting of blood through small vessels in oesophagus and stomach. These vessels may become large and swollen.
What is the safest analgesic to prescribe in liver disease and why?
Paracetamol
NSAIDs cause renal failure and these patients are very sensitive to opiates
What drugs are capable of causing renal failure in liver disease?
NSAIDS, ACE inhibitors, diuretics, aminoglycosides
What are the main causes of renal failure in liver disease?
Drugs, infection, GI bleeding, myoglobinuria, renal tract obstruction
What is the cause of hepatic encephalopathy?
Build up of ‘toxic’ substances including ammonia. Bypass the liver via collaterals and gaining access to the brain.
Ammonia is produced by the breakdown of dietary protein by gut bacteria