liver Flashcards
Describe the drug metabolism of aspirin
Phase I:
- Hydrolysis reaction:
Aspirin + H2O —> Salcylic acid + Ethanoic acid
Phase II:
- Conjugated with glycine or glucuronic acid
- Forms a range of ionised products which can be excreted
What is the metabolism reaction of alcohol
ADH = alcohol dehydrogenase
ALDH = aldehyde dehydrogenase
Ethanol—ADH—> acetaldehyde—ALDH—> Acetate —> CO2 + H20
Functions of the liver
(ADMIReS)
Albumin
Detoxification
Metabolism of carbs and billirubin
Immunity (Kuppfer cells)
Regulation of oestrogen levels
e
Storage (vitamins ADEK, Fe, Cu, fat)
Liver function tests (LFTs) - markers of liver function
- Bilirubin (mainly unconjugated)
- Albumin
- Prothrombin time (PT/INR)
Direct markers of liver damage
- Highun conjugated bilirubin
- Low albumin
- High PT/INR
Enzymes that show liver damage is likely
- AST and ALT
- AST:ALT usually around 1
If your AST levels are too high, it might be a sign of an injury affecting tissues other than the liver. High ALT levels may mean you have a liver injury.
Bilirubin metabolism
1 – Creation of Bilirubin
Reticuloendothelial cells are macrophages which are responsible for the maintenance of the blood, through the destruction of old or abnormal cells. They take up red blood cells and metabolise the haemoglobin present into its individual components; haem and globin. Globin is further broken down into amino acids which are subsequently recycled into new rbcs.
Meanwhile, haem is broken down into iron and biliverdin, a process which is catalysed by haem oxygenase. The iron gets recycled to rbcs, while biliverdin is rapidly reduced (bilverdin reductase) to create unconjugated bilirubin.
2 – Bilirubin Conjugation
In the bloodstream, unconjugated bilirubin binds to albumin to facilitate its transport to the liver. Once in the liver, glucuronic acid is added to unconjugated bilirubin by the enzyme glucuronyl transferase. This forms conjugated bilirubin, which is more soluble. This allows conjugated bilirubin to be excreted into the duodenum in bile.
3 – Bilirubin Excretion
Once in the colon, colonic bacteria deconjugate bilirubin and convert it into urobilinogen. Around 80% of this urobilinogen is further oxidised by intestinal bacteria and converted to stercobilin and then excreted through faeces. It is stercobilin which gives faeces their brown colour.
Around 20% of the urobilinogen is reabsorbed into the bloodstream as part of the enterohepatic circulation. It is carried to the liver where some is recycled for bile production, while a small percentage reaches the kidneys. Here, it is oxidised further into urobilin and then excreted into the urine.
What is the name of the cells responsible for fibrosis?
Stellate
Functions of the peritoneum
In health:
- Visceral lubrication
- Fluid and particulate absorption
In disease:
- Pain perception
- Inflammatory and immune response
- Fibrinolytic activity
Risk factors for biliary tract disease
- Female
- Fat (BMI 30+)
- Forty (+)
- Fertile (pregnant or many children)
- Fair
also:
- Family history
- Fatty liver disease (non-alcoholic)
- T2DM
- Haemolytic conditions
Symptoms of ascending cholangitis
Charcot’s triad:
- RUQ pain
- High fever
- Jaundice
Reynold’s pentad:
- Charcot’s triad + altered mental state + hypotension
Diagnosis of ascending cholangitis
- FBC: leukocytosis
- LFT: high conjugated hyperbilirubinaemia
- Abdo ultrasound for CBD dilation and gallstones
- MRCP: diagnostic
Treatment of ascending cholangitis
- ERCP (bile duct clearance)
- Laproscopic cholecystectomy once stable to prevent recurrence
- Consider risk of sepsis
- Empiricle while waiting Abx - co-amoxiclav
MRCP and ERCP
MRCP = Magnetic resonance cholangio-pancreatography
ERCP = Endoscopic retrogade cholangio-pancreatography
Murphy sign
- RUQ tenderness, ask patient to take a breath in while pressing RUQ
- Will wince or stop inspiring normally in cholecystitis
Symptoms of cholecystitis
- RUQ pain
- Fever
- Tender gallbladder
- Referred pain to tip of right shoulder (phrenic)
- Murphy sign positive
Diagnosis of cholesystitis
- FBC: leukocytosis + neutrophilia
- LFT: normal
- Abdo ultrasound shows thickened gallbladder wall 3mm≤
and stones/sludge in and fluid around gallbladder
Treatment for cholecystitis
- Surgery within 1 week, typically done within 72 hours
- via laproscopic cholecystectomy
- Until then: IV fluids, analgesia, antibiotics if necessary, nothing by mouth
Complications of cholecystitis
- Sepsis
- Gallbladder empyema
- Gangrenous gallbladder
- Perforation
What are gall stones made from?
- Cholestrol (80%)
- Pigment
- Or mixed
Symptoms of gallstones
- Colicky or sharp pain
- Fever
- Jaundice
- Dietary upset
Worse after a fatty meal, may come in episodes
Diagnosis of gall stones
Bloods:
- Alanine transaminase
- Bilirubin
- Amylase
Then:
First line: Abdominal ultrasound to identify gallstones
Or: MRCP (MRI scan) or CT abdomen & pelvis
Aetiology of gall stones
- Cholesterol supersaturation (diet, hormones)
- Genetic (gallbladder motility)
- Haemoglobin turnover (haemolytic anaemia, cirrhosis, sickle cell)
10% of people have gallstones
And they acount for 30% of all acute presentations
Management of gall stones if not treating directly/straight away
- NSAIDs for mild pain
- IM diclofenac for severe pain
- Change lifestyle
- Decrease fat in diet
Treatment of gallstones
Symptomatic OR asymptomatic and stone blocks CBD:
Elective laproscopic cholecystectomy
Radiological drain (cholesystostomy)
ERCP (endoscopy)
Complications of gallstones that may also be signs
- Acute cholecystitis
- Acute cholangitis
- Obstructive jaundice
- Pancreatitis
What is it called when a gall stone is trapped in the common bile duct?
Choledocholelithiasis
What is a hernia?
Protrusion of an organ through a defect in its containing cavity. Typically bowel
Reducible vs irreducible hernias
Reducible - can be pushed back into place
Irreducible:
- Obstructed - intestinal obstruction
- Strangulation - intestinal ischaemia
- Incarcerated - contents fixed in sac due to size or adhesions
Curative treatment for hernias
Surgery
Other types of hernias
- Umbilical (in neonates)
- Incisional (surgical scars)
- Epigastric
- Obturator (Howship-Romberg sign)
- Diastasis recti
- Spigelian
What is a femoral hernia?
- Bowel herniates through femoral cord
- Female, mid-old age
- Very likely to strangulate due to rigid femoral canal borders
Symptom of femoral hernia
Swelling in upper thigh pointing down
Diagnosis of femoral hernia
- Abdo/pelvic ultrasound if unsure
- BUT usually clinical (based on symptoms)
Borders of the femoral TRIANGLE
Sartorius laterally
Adductor longus medially
Inguinal Ligament superiorly
⛵️
Borders of the femoral CANAL (within the femoral triangle)
Femoral vein laterally
Lacunar ligament medially
Inguinal ligament anteriorly
Pectineal ligament posteriorly
Rolling hiatal hernias
- 20%
- LOS stays in the abdomen
- Part of fundis rolls into thorax
Sliding hiatal hernias
- 80%
- LOS slides into abdomen
What is a hiatal hernia?
- Stomach herniates through diaphragm aperture
- Obese women and 50+ year olds
Symptoms of hiatal hernias
- GORD
- Dysphagia
Diagnosis of hiatal hernias
- Barium swallow (diagnostic)
- Oesophago gastro duodenoscopy
- Chest x-ray
What is an inguinal hernia?
- Spermatic cord herniates through inguinal canal
- In males (obviously
- History of heavy lifting/abdopressure
Direct inguinal hernias
- 20%
- In Hesselbach’s triangle
- Medial to inferior epigastrics
Hesselbach’s triangle
Rectus abdominis medially
Inferior epigastric vessels superiorly/laterally
Poupart’s (inguinal) ligament inferiorly
🪦
Indirect inguinal hernias
- 80%
- Not in Hesselbach’s triangle
- Lateral to inferior epigastrics
Symptoms of inguinal hernias
- Painful swelling in groin
- Points along groin margin
Diagnosis of inguinal hernias
- Usually clinical
- Unsure = AUSS (CT/MRI)
Acute vs chronic pancreatitis
Acute
- Reversible acute inflammation of the pancreas
Chronic
- 3+ month history of pancreatic deterioration
- Irreversible pancreatic inflammation + fibrosis
Causes of acute pancreatitis
Idiopathic
Gallstones
Ethanol🍾🍷🍻
Trauma
Steroids
Mumps/malignancy
Autoimmune
Scorpion stings
Hypercalcaemia/hyperlipidaemia
ERCP
Drugs (azathiprine, NSAIDs, ACE inhibitors, tobacco, thiazides)
Pathophysiology of acute pancreatitis
- Gall stones obstruct pancreatic secretions
- Accumulated digestive enzymes in pancreas
- Host defences soon overwhelmed
- Causes autodigestion -> inflammation + enzymes leak in blood
Symptoms of acute pancreatitis
- Sudden severe epigastric pain radiating to the back (DDx: abdominal aortic aneurysm)
- Nausea and vomiting
- Jaundice
- Pyrexia
- Steatorrhoea
- Grey Turner sign and Cullen sign
Diagnosis of acute pancreatitis
- Blood test first line: High serum amylase/lipase
- Cxr to eclude gastroduodenal perforation
- Abdo ultrasound -> diagnostic for gall stones; CT/MRI for extent of damage
Glasgow score for severity of acute pancreatitis
PaO2 < 8KPa
Age > 55
Neutrophils (WBC > 15x109/L)
Calcium > 2mmol/L
Renal urea > 16mmol/L
Enzymes (LDH > 600iu/L or AST > 200iu/L)
Albumin < 32g/L
Sugar, glucose > 10mmol/L
0-1 - mild pancreatitis
2 - moderate pancreatitis
3+ - severe pancreatitis
Treatment for acute pancreatitis
- Rescuscitation if required
- IV fluid
- IV analgesia
- IV antibiotics for infection/associated cholangitis
- Nil by mouth
- ERCP within 72 hours of pain onset if required
Main complication of acute pancreatitis
Systemic inflammatory response syndrome (SIRS)
2 ≤ out of:
- Tachycardia (90+ bpm)
- Tachypnoea (20+ RR)
- Pyrexia (38°c <)
- High WCC
Causes of chronic pancreatitis
- Alcohol (mc)
Also:
- CKD
- CF
- Trauma
- Recurrent acute pancreatitis
- Cancer
- Autoimmune
Symptoms of chronic pancreatitis
- Epigastric pain radiating to back - exacerbated by alcohol
- Exocrine (eg: steatorrhoea) and endocrine (eg: T2DM) dysfunction
- Pseudocysts or abscesses
DDx: Pancreatic cancer, especially of body and tail
Diagnosis of chronic pancreatitis
- Faecal elastase low (indicator of exocrine function)
- Abdo ultrasound and CCT to detect pancreatic calcification and dilated pancreatic duct (diagnostic)
Treatment of chronic pancreatitis
- Alcohol cessation
- Dietary modification
- Analgesia for abdo pain, first line = NSAIDs
- Pancreatic supplements (eg: enzymes, insulin for DM)
- ERCP or surgery if required
Pathophysiology of primary biliary cholangitis
- Intrahepatic autoimmune jaundice affecting intralobular bile ducts
- Autoantibodies cause intralobular bile duct damage; chronic autoimmune granulomatous inflammation
- Resulting in cholestasis -> Fibrosis, cirrhosis, portal hypertension, infection
Risk factors for primary biliary cholangitis
- Female
- 40-50 years old
- Other autoimmune disease
- Smoking
Complications of primary biliary cholangitis
- Malabsorption of fats + vit ADEK (=steatorrhoea)
- Ostemalacia
- Coagulopathy
Symptoms of primary biliary cholestasis
- Initially often asymptomatic
- Routine test shows high anti-mitochondrial antibodies
- Pruritis + fatigue earliest, then jaundice, then hepatosplenomegaly, + xanthelasma
Diagnosis of primary biliary cholangitis
- LFT
- Rule out acute hepatitis by testing for HepBsAg and HVCAb
- Serology
- Rule out extrahepatic cholestasis via ultrasound
- Liver biopsy
LFT and serology results for primary biliary cholangitis
LFT:
- High ALP
- High conjugated bilirubin
- low albumin
Serology:
95% have anti-mitochondrial antibodies (especially M2)
Liver biopsy results for primary biliary cholangitis
- Portal tract infiltrate (lymphocyte + plasma cell)
- 40% granulamatous
- Portal tract fibrosis
Treatment for primary biliary cholangitis
- Ursodeoxycholic acid (reduces intestinal absorption of cholesterol)
- Colestyramine to treat pruritus
- Consider vitamin ADEK supplements
- May ultimately need liver transplant
Pathophysiology of primary sclerosis cholangitis
- Autoimmune destruction of intra + extralobular hepatic duct
- Blocks the flow of bile out of the liver into the intestines
- Chronic bile obstruction eventually leads to liver inflammation (hepatitis), fibrosis and cirrhosis
Risk factors for primary sclerosing cholangitis
- Male
- 40-50
- Strong link to IBD (especially ulcerative cholitis)
Presentation of primary sclerosis cholangitis
- 50% asymptomatic until disease advances
- Charcot’s sign
- Pruritis
- Fatigue
- Hepatosplenomegaly
- IBD
Diagnosis of primary sclerosing cholangitis
- Cholestatic LFT
- GS imaging: MRCP
- Biopsy same as PBC
Serology: - HBVsAg/HCVAb -ve
- AMA -ve
- Coelic screen anti tTG -ve
- pANCA +ve in 33-88%
Treatment of primary sclerosing cholangitis
Conservative:
- Colestyramine for pruritis
- Fat soluble ADEK
- ERCP to dilate and stent structures
- Consider liver transplant
Risk factors for alcoholic liver disease
- Chronic alcohol
- Obesity
- Smoking
- Female gender
- Genetic
Stages of alcoholic liver disease
steatosis (fatty liver, undamaged)
alcohol hepatitis (w/ mallory bodies)
alcohol cirrhosis (micronodular)
Symptoms of alcoholic liver disease
- Early stages may be asymptomatic
Later: - Chronic liver failure symptoms
- Alcohol dependency
- Hepatomegaly
Assessing alcohol dependency
- Alcohol use disorder ID test: 10 questions
- Questionnaire with CAGE questions (>2 = dependent!)
- Should you cut down?
- Are people annoyed by your drinking?
- Do you feel guilty about drinking?
- Do you drink in the morning? (eye opening)
Diagnosis of alcoholic liver disease
Bloods
- LFT shows liver damage
- High GGT-
- (gamma-glutamyl transferase (GGT) test measures the amount of GGT in the blood. GGT is an enzyme found throughout the body, but it is mostly found in the liver. When the liver is damaged, GGT may leak into the bloodstream. High levels of GGT in the blood may be a sign of liver disease or damage to the bile ducts)
-
- AST:ALT > 2
- Macrocytic and megaloblastic anaemia
Biopsy to confirm extent:
- Mallory cytoplasmic inclusion bodies
- Inflammation and necrosis in alcoholic hepatitis
Conservative treatment for alcoholic liver disease
- Healthy diet, lower BMI
- Stop alcohol
Pharmacological treatment for alcoholic liver disease
- Consider steroids short term (Maddrey’s discriminant value of 32)
- IV thiamine (Vit B1) so you don’t develop Wernicke Korsakoff syndrome
- Could also give folate
Surgical treatment for alcoholic liver disease
- Consider liver transplant for ESLF cases-end stage liver failure
- Must have abstained from alcohol for 3+ months
Complications of alcoholic liver disease
- Pancreatitis
- Hepatic Encephalopathy
- Ascites
- HCC= Hepatocellular carcinoma
- Mallory-weiss tear
- Wernicke Korsakoff syndrome
Pathophysiology of ALD
- Alcohol dehydrogenase enzymes and cytochromes (2 ways of metabolism)
Alcohol dehydrogenase and acetaldehyde dehydrogenase reduce nicotinamide adenine dinucleotide (NAD) to NADH (reduced form of NAD). Excessive NADH in relation to NAD inhibits gluconeogenesis and increases fatty acid oxidation, which in turn promotes fatty infiltration in the liver.
oxidative stress promotes hepatocyte necrosis and apoptosis in these patients. Free radicals can also induce lipid peroxidation, which can cause inflammation and fibrosis. The alcohol metabolite acetaldehyde, when bound to cellular protein, produces antigenic adducts and induces inflammation.
- Risk of forming reactive O2 species, more overload = more O2 species
- Eventual scar tissue around central veins, adding to portal hypertension
Delirium tremens+ treatment
- Alcohol stimulates GABA receptors and inhibits glutamate receptors
- Chronic alcohol leads to upregulation of glutamate receptors and downregulation of GABA receptors
- Treat wirh IV Chlordiaepoxide or diazepam
Alcohol units
- 1 unit = 8g/10ml pure alcohol
- Recommended no more than 14 units a week for both men and women
Equation:
strength (ABV) x volume (ml)
dividedby
1000
1000
Alcohol withdrawal
6-12 hours: tremours, sweating, headaches
12-24 hours: hallucination
24-48 hours: seizures
24-72 hours: delirium tremens (medical emergency)
Gilbert’s syndrome
- Most common in males
- T1DM
- Autosomal recessive
- Most common cause of hereditary jaundice
Pathophysiology of Gilbert’s syndrome and Crigler Najjar syndrome
- Autosomal recessive
- Deficient or abnormal UGT (UDP101), reducing UGT activity
- Causes an excess in unconjugated hyperbilirubinaemia
(In Crigler Najjar, UGT is completely gone)
Presentation of Gilbert’s syndrome
- 30% asymptomatic
- Typically males around 20
- May present with painless jaundice at a young age
Symptoms of Crigler Najjar syndrome
- More severe than Gilbert’s
- Jaundice
- Nausea and vomiting
- Lethargy
Treatment of Gilbert’s and Crigler Najjar syndrome
- Gilbert’s: Usually no need
- CN: Phototherapy to break down unconjugated bilirubim
Complications of Crigler Najjar syndrome
- More severe progression chances
- Can die from kernicterus in childhood
- Kernicterus is accumulation of bilirubin in the basal ganglia, causing severe neurological deficits
What do all types of hepatitis show?
Interface necrosis
“Piecemeal necrosis” on histology (don’t ask wjhat it looks like bc idk)
Pathophysiology of autoimune hepatitis
- Chronic inflammation of the liver - aka: lupoid hepatitis, very rare
- T helper cell mediated response vs hepatocytes
Risk factors for autoimmune hepatitis
- Female:male, 4:1
- Nitrofurantoin use
- Other autoimmune diseases
- Viral hepatitis
- HLA DR3 or DR4
Type 1 autoimmune hepatitis
- Adult females
- 80% of cases
- ANA - antinuclear antibody (found in many other autoimmune diseases but very specific for Type 1 autoimmune hep)
- ASMA - antismooth muscle antibody
Type 2 autoimmune hepatitis
- Young females
- Rarer
- ALC-1 (antiliver cystosol)
- ALKM-1 (antiliver-kidney microsome)
Presentation of autoimmune hepatitis
- 25% asymptomatic
- Many = jaundice, fever, hepatosplenomegaly
- Anorexia
- Lupus-like rash