Liver and Friends Flashcards
What are the functions of the liver
Glucose and fat metabolism
Detoxification and excretion (Bilirubin, ammonia, drugs)
Protein synthesis (Albumin and clotting factors)
Defence against infection
What are the two types of liver injury
Acute - damage to and loss of cells with death occurring by necrosis or apoptosis <6months
Chronic - chronic damage leading to fibrosis (Cirrhosis)
What are the causes of acute liver injury
Viral (Hep A, B and EBV) Drugs Alcohol Vascular Obstruction Congestion
What are the causes of chronic liver injury
Alcohol
Viral B and C
Autoimmune
Metabolic (iron, copper)
What is the presentation of acute liver injury
Malaise Nausea Anorexia Jaundice Confusion - encephalopathy Bleeding - lack of clotting factors Liver Pain Hypoglycaemia
What is the presentation of chronic liver injury
Ascites Oedema Haematemesis Malaise Weight loss Anorexia Wasting Easy bruising Itching Hepatomegaly Jaundice Confusion
Name three serum liver function tests
Serum bilirubin
Serum albumin
Prothrombin time
Do serum liver enzymes give an index of liver function
No
Name enzymes that increase in the serum in cholestatic liver disease (Duct and obstructive)
Alkaline Phosphate (Raised in both intrahepatic and extra hepatic cholestactic)
Gamma-GT (Microsomal liver enzyme)
What enzyme increases in serum hepatocellular liver disease
Transaminases (ALT and AST
What do elevated transaminases indicate
Enzymes are contained in hepatocytes and leak into the blood with liver cell damage
Anti-mitochondrial antibodies are seen in the serum with what condition
Primary billiary cirrhosis
Anti-nuclear cytoplasmic antibodies are fond in the serum of patients with what condition
Primary sclerosis cholangitis
What is a normal bilirubin concentration
3-17uM
At what bilirubin concentration does jaundice become visible
50uM
Describe the physiology of bile production
- Hb broken into globin and haem
- Haem broken down into biliverdin
- Biliverdin reduced by biliverdin reductase into unconjugated bilirubin which is transported to the liver bound to albumin
- Unconjugated bilirubin is converted to conjugated bilirubin by glucuronidation by uridine glucuronyl transferase in the liver
- Conjuagted bilirubin converted to urobilinogen which is reabsorbed and returned to the liver and re-excreted into the bile
- Some reabsorbed urobilinogen is excreted into the urine as urobilin
- Urobilinogen that remains in the GIT is converted to stercobilin and excreted
What are the pre-hepatic causes of jaundice?
Excess unconjugated bilirubin production due to haemolytic anaemia or ineffective erythropoiesis (Thalassaemia)
What are the unconjugated hepatic causes of jaundice
- Decreased bilirubin uptake due to drugs
2. Decreased bilirubin conjugation due to Gilberts syndrome or Crigler-Najjar or hypothyroidism
What is Gilbert’s disease
Autosomal dominant condition resulting in a partial deficiency in UDP-GT which increases unconjugated bilirubin
What is Crigler Najjar syndrome
Autosomal recessive condition resulting in a total UDP-GT deficiency
What are the conjugated hepatic causes of jaundice
- Hepatocellular dysfunction
- Congenital (wilson’s, A1ATD)
- Infection Hep A/B/C, CMV and EBV
- Toxins (EtOH and drugs)
- Autoimmune hepatitis
- Hepatocellular carcinoma - Decreased hepatic bilirubin excretion
- Dubin-Johnson (MRP2 mutation)
What are the post hepatic causes of jaundice
Obstruction
- Stones
- Drugs
- Primary biliary cirrhosis
- Primary sclerosing cholangitis
- mirrizi
- malignant
What colour is the urine in pre-hepatic jaundice
Normal
What colour is the urine in cholestatic (hepatic or post hepatic) jaundice
Dark
What colour are stools in pre hepatic jaundice
Normal
What colour are stools in cholestatic jaundice
Pale
Are liver tests normal or abnormal in prehepatic jaundice
Normal
Are liver tests normal or abnormal in cholestatic jaundice
Abnormal
What investigative tests would you carry out in a jaundiced patient
- Very high AST/ALT
- Dilated intrahepatic bile ducts on ultrasound
- CT
- MRI
Where do gall stones most commonly form
Gallbladder
Are gall stones more common in men or women
Women
Are gall stones normally symptomatic or asymptomatic
Asymptomatic
What are the risk factors for gall stones
Female
Fat
Fertile
Smoking
What are the two main types of gall stone
Cholesterol stones (80%) Bile pigment stones
Why do cholesterol gall stones form
Consequence of cholesterol crystallisation
- Cholesterol supersaturation of bile
- Deficiency of bile salts and phospholipids
- Gall bladder stasis
Why do bile pigment stones form
Haemolysis - sickle cell
What are the two types of bile pigment stones
- Black pigment - calcium bilirubinate + Salts
2. Brown pigment - calcium salts and fatty acids
What is bilary colic
Pain associated with temporary obstruction of cystic or common bile duct by stone migrating from gall bladder
What are the symptoms of biliary colic
Pain is severe and constant with crescendo
initial site of pain is epigastrium but may be RUQ
Nausea and vomiting accompanying severe attacks
What is acute cholecystitis
Gall bladder inflammation due to obstruction to gall bladder emptying
What investigations would you carry out in someone with gall stones
Serum bilirubin/alkaline phosphatase and amintransferase are elevated
Abdominal ultrasound
What is the management of gall stones
Laproscopic cholecystectomy
Bile acid dissolution therapy = ursodeoxycholic acid
Extracorpeal shock wave lithotripsy
What are the three types of drug induced liver injury
Hepatocellular
Cholestatic
Mixed
What drugs most commonly cause drug induced liver injury
- Antibiotics (Flucoxacillin
- CNS drugs (Chlorpromazine)
- Analgesics (Diclofenac)
- Gastrointestinal drugs
What is paracetamol conjugated with in its phase II reaction
Glucuronic acid
What enzyme is responsible for mopping up reactive intermediates of paracetamol so prevents toxicity
Glutathione transferase
What is the highly reactive toxic intermediate in paracetamol metabolism
NAPQI
What is the clinical presentation of paracetamol poisoning
Asymptomatic for first 24 hr followed by anorexia, nausea, vomiting and RUQ pain
Jaundice and encephalopathy due to liver damage
What is the management of paracetamol toxicity
N acetyl cysteine which repletes glutathione stores
Supportive care to correct for coagulation defects, renal failure, hypoglycaemia
What is liver failure
When the liver loses ability to regenerate or repair as decompensation occurs
What are the three types of liver failure
- Acute = sudden liver failure with previously healthy liver
- Chronic = Liver failure on background of cirrhosis
- Fulminant = massive necrosis of liver cells
What are the causes of liver failure
Cirrhosis
Infection
- Hep A/B, CMV, EBV, Leptospirosis
Toxin
- EtOH, Paracetamol, isoniazid, halothane
Metabolic
- Wilsons, AIH, A1ATD, Haemochromatosis
Neoplastic = HCC
What are the signs of liver failure
Jaundice oedema and ascites Bruising Encephalopathy - Aterixis (Flapping tremor) - Apraxia Fetor Hepaticus (Breath smells sweet) Signs or cirrhosis
What investigations would you carry out in someone with liver failure
AST:ALT >2 = EtOH
AST:ALT <1 = viral
Albumin is decreased in chronic liver failure
Prothrombin time increase in acute liver failure
What is the management of liver failure
Treat the underlying cause
Good nutrition
Thiamine supplements
Give three causes of iron overload
- Genetic disorders (Haemochromatosis)
- Multiple blod transfusions
- Haemolysis
- Alcoholic liver disease
What is cirrhosis
A chronic disease of the liver resulting from necrosis of the liver cells followed by fibrosis - the end result is impairment of hepatocyte function and distortion of liver architecture
What are the two types of cirrhosis
- Micronodular - regenerating nodules <3mm all over liver
2. Macronodular - Nodules of variable size
What causes micro nodular cirrhosis
Chronic alcohol
Biliary tract disease
What causes macro nodular cirrhosis
Chronic hepatitis
What are the causes of cirrhosis
Chronic alcohol Chronic hepatitis C and B Genetic - Wilson's/ a1ATD Autoimmune - Autoimmune hepatitis - Primary biliary cholangitis Drugs - Methotrexate, Amiodarone, methyldopa Neoplasm - HCC
What are the signs of cirrhosis in the hands
Clubbing Leuconychia Terry's nails Palmar erythema Dupuytron's Contracture
What are the sings of cirrhosis in the face
Pallor
Xanthelasma
What are the signs of cirrhosis in the trunk
Spider naevi
Gynaecomastia
Loss of secondary sexual hair
What are the abdominal signs of cirrhosis
Striae Hepatomegaly Splenomegaly Caput medusa Testicular atrophy
What are the complications of cirrhosis
- Decompensation = hepatic failure
- Jaundice
- Encephalopathy
- Hypoalbuminaemia
- Hypoglycaemia
- Coagulopathy - Spontaneous bacterial peritonitis
- Portal hypertension
- Increased risk of HCC
What investigations would you conduct in someone with cirrhosis
Decreased WCC
Increased LFTs
Decreased albumin and prolonged prothrombin time
Abdominal ultrasound showing small or largee liver with focal marginal nodularity
Liver biopsy to confirm the type and severity
What is the management for cirrhosis
Good nutrition - decrease Na+ EtOH abstinence Colestyramine for pruritus Avoid NSAIDs and aspirin Screen for HCC with ultrasound Fluid restriction with spironolocatone
Portal vein is formed by the union of what veins
Superior mesenteric and splenic veins
Describe the pathophysiology of portal hypertension
Liver cirrhosis increases resistance of blood flow in the liver increasing pressure into the portal system. When the venous pressure increases to 10-12mmHg the venous system dilates and collaterals form
What are pre-hepatic causes of portal hypertension
Blockage of portal vein before the liver due to portal vein thrombosis (Pancreatitis)
What are the hepatic causes of portal hypertension
Distortion of the liver architecture due to cirrhosis and schistosomiasis and sarcoidosis
What are the post-hepatic causes of portal hypertension
Blockage of the portal vein outside the liver due to Budd chiari, constrictive pericarditis and RHF
Where do varices form following portal hypertension
Gastro-oesophageal junction
Ileocaecal junction
Rectum
Anterior abdominal wall
What are the symptoms of portal hypertension
Splenomegaly Ascites Varices Encephalopathy Haematemesis Breathlessness
What investigations would you carry out in someone with portal hypertension
Portal vein blockage can be identified on ultrasound with Doppler imaging
What are the potential consequences of portal hypertension induced varices
If they rupture = haemorrhage
What is the treatment for varices
Endoscopic therapy = banding
Describe the pathophysiology of encephalopathy
- Decreased hepatic metabolic function
- Diversion of toxins from the liver directly into the systemic circulation due to collaterals around the liver
- Ammonia accumulates and passes to the brain where astrocytes Clear it causing glutamate conversion to glutamine
- Increased glutamine alters osmotic imbalance and causes cerebral oedema
What are the 4 classification stages of encephalopathy
- Confused (Irritable, confusion, sleep)
- Drowsy (Disorientated, slurred speech, asterixis)
- Stupor (rousable, incoherence)
- Coma (Unrousable)
What is the presentation of encephalopathy
Asterixis (Coarse flapping tremor when hands are outstretched)
Ataxia
Fetor Hepaticus = sweet breath
confusion
Dysarthia
Constructional apraxia (Unable to write or draw)
Seizures
What are the precipitants of encephalopathy (remember hepatics)
Haemorrhage (Varicies) Electrolytes (Decreased K+/Na+ Poisons (Diuretics, sedatives, anaesthetics) Alcohol Tumour (HCC) Infection (SBP, Pneumonia) Constipation Sugar decrease
What investigation result would you expect to see in someone with encephalopathy
Increased plasma ammonia
What is the treatment for encephalopathy
Correct precipitants
Lactulose (limits ammonia absorption) and PO4 enemas to decrease nitrogen forming bowel bacteria
Consider rifaximin to kill intestinal microflora
What is ascites
An accumulation of fluid in the peritoneal cavity leading to abdominal distension
What is the pathophysiology of ascites
Portal hypertension leads to fluid exudation leading to an effective drop in circulating volume - this leads to RAAS activation causing Na+ and H2O retention
In cirrhosis a decrease in albumin leads to decreased plasma oncotic pressure and aldosterone metabolism is impaired
What are the causes of ascites
Local inflammation - peritonitis
Leaky vessels - imbalance between hydrostatic and oncotic pressure
Low flow - cirrhosis, cardiac failure and thrombosis
Low protein - hypoalbuminaemia
What are the symptoms of ascites
Distension - abdominal discomfort, swelling and anorexia
Dyspnoea
Decreased venous return
How do you determine the cause of ascites
Serum ascites albumin gradient
- > 1.1g/dL = Portal HTN (Pre-hepatic and post and cirrhosis )
- <1.1g/dL = other causes
(Neoplasia, inflammation (peritonitis), nephrotic syndrome, infection (TB peritonitis)
how do you determine the serum ascites albumin gradient
Serum albumin - Ascites albumin
What investigations would you Carry out in someone with suspected ascites
Bloods
Ultrasound
Ascitic tap
Liver biopsy
What is the treatment for ascites
Weight reduction Fluid restriction <1.5L/d Low Na+ diet Spironolatone (Aldosterone antagonist) Therapeutic paracentesis
What is spontaneous bacterial peritonitis
Ascites and peritonitis abdomen
What are the causes of spontaneous bacterial peritonitis
E.Coli, Klebsiella, Steps, Enterococci
What are the three phases of alcoholic liver disease
- Fatty change - hepatocytes contain triglycerides
- Alcohol hepatitis
- Cirrhosis - destruction of architecture and fibrosis
What might be seen histologically that indicates a diagnosis of alcoholic liver disease
Neutrophils and fat accumulation within hepatocytes
What are the effects of alcoholism on the GIT
Gastritis Peptic Ulcer Disease Varices Pancreatitis Carcinoma
What are the effects of alcoholism on the CNS
Poor memory Peripheral polyneuropathy Wernicke's Encephalopathy - Confusion - Ophthalmoplegia - Ataxia Korsakoffs - amnesia
What are the effects of alcoholism on the heart
Arrhythmia ie AF
Dilated cardiomyopathy
Increased Bp
What are the effects of alcoholism on the blood
Increased mean corpuscular volume
Folate deficiency - anaemia
What are the CAGE questions for alcoholism
Do you think you should cut down
Are you annoyed by peoples criticism’s
Are you guilty about drinking
Do you need a drink to get up in the morning
What Is the treatment for alcoholism
Group therapy or self help
Baculofen and acamprosate to reduce cravings
Disulfiram = aversion therapy
What is the presentation of alcoholic hepatitis
Anorexia Diarrhoea and vomiting Tender hepatomegaly Ascites Severe jaundice, bleeding, encephalopathy
What investigations and results would you see in alcoholic hepatitis
Bloods= increased MCV, increased GTT
AST:ALT >2 = EtOH
Ascititic Tap
Abdo ultrasound
What is the treatment for alcoholic hepatitis
Stop EtOH
High does B vitamins (Thiamine)
Optimise nutrition
Manage the complications of failure
What is non alcoholic fatty liver disease
Cryptogenic cause of hepatitis and cirrhosis associated with insulin resistance and metabolic syndrome
What is the most severe form of non alcoholic fatty liver disease
Non alcoholic steatohepatitis
What are the risk factors for NAFLD
Obesity
Hypertension
T2DM
Hyperlipidaemia
What is the presentation of NAFLD
Mostly asymptomatic
Hepatomegaly and RUQ discomfort
What investigations would you carry out in someone with NAFLD
BMI
Glucose
Increase transaminases AST:ALT <1
Liver biopsy to enable staging
What is the management of NAFLD
Lose weight
Control hypertension, diabetes mellitus and lipids
Exercise
What is budd-chiari syndrome
Hepatic vein obstruction –> Ischaemia and hepatocyte damage –> Liver failure
Give 4 reasons why liver patients are vulnerable to infection
- Have impaired reticule-endothelial function
- Reduced opsonic activity
- Leukocyte function is reduced
- Permeable gut wall
Name 3 metabolic disorders that can cause liver disease
- Haemochromatosis
- Alpha 1-antitrypsin deficiency
- Wilson’s disease
What is haemochromatosis
metabolic disorder resulting in excess Fe2+ deposits in organs leading to fibrosis and organ failure
What is the age of onset for haemochromatosis
40-60 years
What is the genetic cause of haemochromatosis
Autosomal recessive condition causing mutation in the Human haemochromatosis protein (HFE) –> C282Y
What is the pathophysiology of haemochromatosis
Increased intestinal Fe absorption resulting in deposition in liver heart joints endocrine, skin and pancreas leading to fibrosis and functional organ failure
What are the clinical features of haemochromatosis (Remember MEALS)
Myocardial
- dilated cardiomyopathy
- Arrhythmia
Endocrine
- DM
- Pituitary = hypogonadism
- Parathyroid = hypocalcaemia, osteoporosis
Arthritis
Liver
- Chronic liver disease leading to cirrhosis leading to HCC
- Hepatomegaly
Skin
- Slate grey discolouration
- bronze skin pigmentation
How might you diagnose someone with haemochromatosis
Raised ferritin increasing LFT Increased Fe Liver biopsy - pearls stain to quantify the FE MRI can estimate iron loading ECHO and ECG for cardiac complications X-ray shows chondrocalcinosis HFE genotyping
What is the treatment for haemochromatosis
venesection - regular removal of blood to use up some excess iron to make new RBC’s
In patients who cant have venesection they can have chelation therapy (Desferrioxamine) which prevents iron absorption
Low iron Diet
Treat DM complication
Look for transplant in cirrhosis and screen 1st degree relatives
What is the pathophysiology of alpha 1 antitrypsin deficiency
a1AT is serine involved in control of inflammatory cascade by inhibiting neutrophil elastase
A1AT is synthesised by the liver and a deficiency results in lung damage
What is the presentation of alpha 1 anti-trypsin
Neonatal and childhood hepatitis
15% adults develop cirrhosis
75% have emphysema
5% die of liver disease
What investigations and results would you see in someone with alpha 1 antitrypsin deficiency
decreased a1AT levels
Liver biopsy = +ve periodic acid shift
Emphysematous changes on CXR
Obstructive defect on spirometry
What is the management of alpha 1 anti-trypsin deficiency
Quit smoking
Mostly supportive for pulmonary and hepatic complications
Consider a1AT therapy from donors
Patients with hepatic decompensation should get liver transplant
What is Wilson’s disease
Autosomal recessive disorder of copper metabolism where there is deposition of copper in the liver which can lead to fulminant hepatic failure and cirrhosis
When does Wilsons disease most commonly present
Between childhood and 30
What is the genetic cause of Wilsons disease
Autosomal recessive ATP7B gene on chromosome 13
Describe the pathophysiology of Wilson’s disease
Mutation of Cu transporting ATPase leading to impaired hepatocyte incorporation of Cu into caeruloplasmin and excretion into bile causingg Cu accumulation in liver and other organs
What are the clinical features of Wilson’s disease (Remember CLANKAH)
Cornea (Kayser-Fleischer rings)
Liver disease (Acute hepatitis in children and necrosis and cirrhosis in adults)
Arthritis
- Osteoporosis
Neurology
- Parkinsonism =bradykinesia, tremor, ataxia
Kidney
- Fanconi’s syndrome
Haemolytic anaemia
What are the investigative results in Wilson’s disease
Decreased copper and caeruloplasmin
increased urinay copper
Increased hepatic copper
MRI = basal ganglia degeneration