Liver and GI Flashcards
What causes death when the liver fails?
Hypoglycaemia due to failed glucogenesis and glycogenolysis
What are the functions of the liver?
- Protein synthesis (albumin, clotting factors)
- Glucose and fat metabolism
- Defence against infection
- Detoxification and excretion (e.g. ammonia, drugs, hormones)
Where does the liver get its blood supply?
Dual supply from portal vein from the gut and hepatic artery
Which vessel carries blood away from the liver?
Hepatic vein
Which part of the liver lobule is most likely to be affected by toxins?
Zone 3 (i.e. the hepatocytes around the hepatic vein as these have the least access to oxygen and nutrients)
What does acute liver injury lead to?
Either liver failure or recovery
What does chronic liver injury lead to?
Either recovery or cirrhosis (which can lead on to acute on chronic liver failure, varices and hepatoma)
What is seen on histology in acute liver injury?
- Apoptosis (seen as eosinophilic areas)
- Fibrosis
- Macrophages
- Ballooned hepatocytes
How does acute liver injury present?
Malaise, nausea, anorexia, jaundice (rarely - confusion and liver pain)
How does chronic liver injury present?
Ascites, oedema, haematemesis, malaise, anorexia, wasting, easy bruising, itching, hepatomegaly, abnormal LFTs
(rarely - jaundice, confusion)
Which blood tests give some index of liver function?
Serum bilirubin, albumin and prothrombin time
Which blood ‘liver function tests’ actually give no index of liver function?
Serum liver enzymes, alkaline phosphatase, gamma-GT, transaminases (AST, ALT)
What is jaundice?
Yellow appearance of the skin caused by raised serum bilirubin
What is pre-hepatic jaundice and what causes it?
Pre-hepatic jaundice is caused by raised unconjugated serum bilirubin and is caused by Gilbert’s syndrome and haemolysis
Raised conjugated bilirubin is found in which types of jaundice?
Hepatic (liver disease), post-hepatic (due to bile duct obstruction)
What is Gilbert’s syndrome?
An inherited liver disorder that affects the body’s ability to process bilirubin - don’t produce enough liver enzymes to keep bilirubin at a normal level
What are the possible causes of hepatic jaundice?
Hepatitis (caused by drugs/autoimmune/alcohol), ischaemia, neoplasm and congestion
What are the possible causes of post-hepatic jaundice?
Gallstones, malignancy, ischaemia, inflammation
How can we differentiate between pre-hepatic and hepatic/post-hepatic jaundice?
Pre-hepatic: normal urine, normal stools, no itching, normal liver tests
Hepatic/post-hepatic: Dark urine, potentially pale stools, possible itching, abnormal liver tests
What does very high AST/ALT suggest?
Liver disease (although some exceptions), jaundice with high AST/ALT enzymes more likely to have hepatic cause.
Besides blood tests, what other investigations can be useful in assessing jaundice?
CT
MRCP (magnetic resonance cholangiogram)
ERCP (endoscopic retrograde cholangiogram)
What are gallstones made of?
Cholesterol, bile duct pigment +/- calcium
What are the three classifications of gallstones?
- Intrahepatic bile duct stones (hepatolithiasis)
- Extrahepatic bile duct stones (choledocholithiasis) in the common bile duct
- Gallbladder stones (cholecystolithiasis)
How do gallbladder stones (cholecystolithiasis) normally present?
Right upper quadrant pain, cholecystitis, possible obstructive jaundice, no evidence of cholangitis or pancreatitis
How do bile duct stones (choledocholithiasis) normally present?
No cholecystitis or ‘biliary’ pain. Obstructive jaundice, cholangitis and pancreatitis present.
How are gallbladder stones normally managed?
Via laparoscopic cholecystectomy (if symptomatic)
Can offer bile acid dissolution therapy instead if patient is not fit for surgery
How are bile duct stones usually managed?
ERCP with sphincterotomy with removal (via basket or balloon), crushing (mechanical/laser) and possible stent placement.
Large stones may need to be removed surgically.
Acute stone obstruction will normally show what on liver enzyme tests?
Alkaline phosphatase usually normal
Initial ALT often high >1000
Which antibiotic used to treat and prevent TB can be associated with elevated transaminases?
Isoniazid
Which drugs are most likely to cause liver injury?
Antibiotics, CNS drugs (e.g. valproate, carbamazepine), immunosuppressants (e.g. azathioprine), analgesics (e.g. diclofenac), GI drugs (e.g. PPIs), dietary supplements.
What drugs apparently don’t cause liver injury?
Low dose aspirin NSAIDs (except diclofenac) Beta blockers HRT ACE inhibitors Thiazides Calcium channel blockers
What drug is given to treat paracetamol overdose?
N acetylcysteine (NAC)
When might a paracetamol overdose require an emergency liver transplant?
- Late presentation (NAC less effective >24h)
- Acidosis
- Prothrombin time >70s
- Serum creatinine >300umol/l
Why is ascites associated with chronic liver disease?
CLD causes systemic dilatation, which leads to the secretion of renin, noradrenaline and vasopressin, which causes fluid retention.
Low albumin also leads to ascites.
What are the management options for ascites?
Fluid and salt restriction, high caloric intake
Diuretics: spironolactone +/- furosemide
To drain fluid:
Large-volume paracentesis
Trans-jugular intrahepatic portosystemic shunt (TIPS)
What is normally seen in the early stages of alcoholic liver disease?
Fatty liver
What is cirrhosis of the liver?
Irreversible architectural change to the liver due to fibrosis
What is the main cause of liver death in the UK?
Alcoholic liver disease
Why might a patient with liver disease present with haematemesis?
Due to bleeding varices in the oesophagus
What drug can be used to treat alcoholic liver disease, although the response is variable?
Prednisolone
What are the main reversible causes of encephalopathy in liver disease patients?
- Constipation
- Drugs
- GI bleed
- Infection
- Hypo- (natraemia, kalaemia, glycaemia..)
What infections are liver patients vulnerable to?
Spontaneous bacterial peritonitis, septicaemia, pneumonia, skin infections, UTIs
What is the most common serious infection seen in liver cirrhosis patients?
Spontaneous bacterial peritonitis
What might cause renal failure in liver disease patients?
Drugs (esp. diuretics, NSAIDs, ACE inhibitors)
Infection, GI bleeding, myoglobinuria, renal tract obstruction
What drugs must be avoided completely in patients with liver disease?
NSAIDs (due to renal failure)
ACE inhibitors (although these patients don’t tend to have high BP anyway)
Aminoglycosides (e.g. gentamicin)
What are the possible causes of chronic liver disease?
- Alcohol
- NASH (Non-alcoholic steatohepatitis)
- Viral hepatitis
- Immune disease (e.g. autoimmune hepatitis, primary biliary cholangitis, sclerosing cholangitis)
- Metabolic disease: haemochromatosis, Wilson’s disease, alpha-1 antitrypsin deficiency
- Vascular disease: Budd-Chiari
Which immunoglobulin is raised in autoimmune hepatitis?
IgG
Which immunoglobulin is raised in primary biliary cholangitis?
IgM
What are the three main autoimmune liver diseases?
Autoimmune hepatitis
Primary biliary cholangitis
Primary sclerosing cholangitis
Which autoimmune liver disease responds well to steroid treatment with prednisolone +/- azathioprine?
Autoimmune hepatitis
How can primary biliary cirrhosis/cholangitis present?
Asymptomatic abnormal LFTs (bilirubin, thrombin time, albumin), itching, fatigue, dry eyes, joint pain, variceal bleeding, liver failure.
What can be used to treat cholestatic itch?
- Antihistamines don’t help much
- Cholestyramine helps in 50% of cases
- Opiate antagonists (e.g. naloxone)
- UV light
- Plasmapheresis
What can be used to treat fatigue in primary biliary cholangitis?
Modafinil
What abnormalities would show up on blood tests for primary sclerosing cholangitis?
Raised alkaline phosphatase and GGT
How does primary sclerosing cholangitis often present?
Itching, pain +/- rigors, jaundice
What are the clinical features of haemochromatosis?
- Hepatomegaly
- Cirrhosis
- Hepatocellular carcinoma
- Flat, white nails
- Koilonychia (spoon nails)
- Joint pain and osteoporosis
- Chronic fatigue
- Diabetes mellitus
- Melanoderma, skin dryness
What would a liver biopsy of a patient with hepatocellular carcinoma show?
Hepatocytes growing in large clumps with large nuclei
What do 50% of hepatocellular carcinoma patients produce?
Alpha fetoprotein
What drug has recently been shown to extend the lives of patients with hepatocellular carcinoma?
Sorafenib
How might hepatic vein occlusion present?
Abnormal liver tests
Ascites
Acute liver failure
What are the treatment options for hepatic vein occlusion?
Anticoagulation
Transjugular intrahepatic portosystemic shunt
Liver transplantation
What is the definition of diarrhoea?
The passage of increased loose/watery stools, at least 3 times in 24 hours
How are acute, persistent and chronic diarrhoea defined?
Acute - 14 days or fewer
Persistent - 14-30 days
Chronic - >30 days
What is dysentery?
An infection of the GIT that leads to diarrhoea containing blood or mucus
What are the potential non-infective causes of diarrhoea?
Cancer and related treatments, chemical diarrhoea (poisoning, medication, sweeteners), IBD (Crohn’s, UC), IBS, malabsorption, endocrine causes (e.g. thyrotoxicosis)
Which common viruses cause watery diarrhoea?
Rotavirus, norovirus
Which parasites cause watery diarrhoea?
Giardia and cryptosporidium
What are the 6 pathogenic serotypes of E coli?
- ETEC (enterotoxigenic)
- EHEC (enterohaemorrhagic
- EIEC (enteroinvasive)
- EPEC (enteropathogenic)
- EAEC (enteroaggregative)
- DAEC (diffusely adherent)
What is the most common cause of traveller’s diarrhoea?
Enterotoxigenic E coli (ETEC)
What pathogen associated with canned meat can cause severe diarrhoea and vomiting?
Clostridium perfringens
What bacterium can cause a type of quick-onset self-limiting food poisoning as a result of food not being refrigerated?
Staph aureus
Persistent infective diarrhoea is more likely to be caused by which pathogens?
Parasites - Giardia, Cryptosporidium
Which invasive bacteria cause diarrhoea?
CESSY Campylobacter E Coli (EIEC, STEC) Salmonella enteritidis Shigella dysenteriae Yersinia (rare)
Which antibiotics have the biggest association with diarrhoea?
Cephalosporins (Cefuroxime, Cefalexin, Ceftriaxone)
Clindamycin
Co-amoxiclav
Ciprofloxacin
What pathogen causes significant diarrhoea in healthcare settings as a result of antibiotics killing off the natural protective bacteria in the gut?
Clostridioides (previously known as C diff)
What drug is used to treat clostridioides?
Vancomycin
What stool tests should be requested when investigating diarrhoea?
Microscopy Culture Multi-pathogen molecular panels Ova, cysts and parasites Toxin detection
What blood tests should be requested when investigating diarrhoea?
Blood cultures
Inflammatory markers
Electrolytes and creatinine
What are the ‘red flags’ for diarrhoea patients?
- Dehydration
- Electrolyte imbalance
- Renal failure
- Immunocompromise
- Severe abdominal pain
- Cancer risk factors (over 50, chronic diarrhoea, weight loss, blood in stool, FH of cancer)
What are the two types of liver abscesses?
- Pyogenic (pus forming - bacterial)
2. Amoebic
How do liver abscesses present?
Fever, RUQ pain, nausea, vomiting, anorexia, weight loss, malaise
How are liver abscesses diagnosed?
Imaging - abdo CT/USS
Blood cultures
Aspirate and culture of abscess material
How are liver abscesses treated?
Drainage and antibiotics
Which pathogen increases the risk of gastritis and peptic ulcers?
Helicobacter pylori
What is the treatment for H pylori?
Omeprazole (or other PPI), clarithromycin and amoxicillin
How is H pylori diagnosed?
Stool antigen test
Breath test
Blood test for antibodies
Endoscopy for biopsy (biopsy urease test, histology)
Which pathogens cause enteric fever?
Salmonella typhi (typhoid) Salmonella paratyphi (paratyphoid)
How does enteric fever present?
Generalised abdominal pain, fever and chills Headache and myalgia Relative bradycardia Rose spots (rare) Constipation/green diarrhoea
How is enteric fever diagnosed?
Blood/bone marrow cultures
What are the potential complications of enteric fever?
GI bleed, perforation/peritonitis, myocarditis, abscesses
What antibiotics can be used to treat enteric fever?
Azithromycin, ciprofloxacin, cephalosporins
Meropenem only as a last resort
What are the three types of GI obstruction?
- Intraluminal obstruction
- Intramural obstruction
- Extramural obstruction
Name three possible causes of intraluminal obstruction in the gut.
- Tumours - more common in the large bowel
- Diaphragm disease - a fibrous diaphragm forms in the gut lumen, leaving only a tiny hole for contents to move through
- Gallstone ileus - caused by massive gallstone forming a fistula so the gallstone ends up in the bowel (rare)