Liver Failure & Cirrhosis (ALD, NASH) & Varices Flashcards
Define;
- Acute Hepatic Failure
- Acute-on-Chronic Hepatic Failure (aka decompensation)
- Fulminant Hepatic Failure
- Hyperacute Fulminant Hepatic Failure
- Acute Fulminant Hepatic Failure
- Subacute Fulminant Hepatic Failure
Acute Hepatic Failure
- Liver failure occuring suddenly in previously health liver
Acute-on-Chronic Hepatic Failure
- Decompensation of chronic liver disease
Fulminant Hepatic Failure
- Clinical syndrome resulting from massive necrosis of liver cells leading to severe impairment of liver function
-
Hyperacute Fulminant Hepatic Failure
- Encephalopathy within 7d of onset of jaundice
-
Acute Fulminant Hepatic Failure
- Encephalopathy within 8-28d of onset of jaundice
-
Subacute Fulminant Hepatic Failure
- Encephalopathy within 5-26wks of onset of jaundice
Define Cirrhosis
What is its histological findings?
Irreversible liver damage.
Histologically - loss of normal hepatic architecture + fibrosis and nodular regeneration
What risk is increased with the acuteness of onset of encephalopathy in Fulminant Hepatic Failure
The more acutely Encephalopathy develops; the increased risk of cerebral oedema occuring
What are the causes of liver failure?
- Infections
- Viral Hepatitis (HBV, HCV, CMV)
- Yellow fever
- Leptospirosis
- Drugs
- Paracetamol overdose
- Halothane (anaesthetic)
- Isoniazid (TB)
- Toxins
- Amanita phalloides mushroom
- Carbon tetrachloride
- Vascular
- Budd-Chiari syndrome
- Veno-occlusive disease
- Others
- Alcohol
- 1° Biliary Cirrhosis
- Haemochromatosis
- Autoimmune hepatitis
- a1-antitrypsin deficiency
- Wilson’s disease
- Fatty liver of pregnancy
- HELLP syndrome
- Malignancy
What are the causes of cirrhosis?
Most commonly;
- Chronic alcohol abuse
- HBV & HCV
- Non-alcoholic steatohepatitis
- Genetic disorders;
- a1-antitrypsin deficiency
- Haemachromatosis
- Wilson’s disease
- Anything that causes Hepatic Failure potentially can cause Cirrhosis
Outline the pathophysiology of Alcoholic Cirrhosis
- Inflammation of space of Disse
- Alcohol is solvent to lipid membrane
- Alcohol (NAD) ⇒ Acetaldehyde (NADH)
- High alcohol conversion uses up NAD
- NAD is used in gluconeogenesis & fatty acid oxidation
- Low NAD ⇒ fatty acid production + Inc lactate
- ⇒ Fatty depositions
- Lactic acidosis
- Acetaldehyde is toxic
- Cytochrome p450 CYP2E1 metabolsim
- produces ROS ⇒ lipid peroxidation of membrances + antioxidant deplettion
- Alcohol causes endotoxin release (LPS) from gram -ve bacteria in intestinal flora ⇒ TNF from cells ⇒ inflammation
- Stellate cells ⇒ myofibroblasts
- ROS, GF, cytokines (TNF, IL1), lymphotoxins & +ve feedback
- ⇒ Collagen (1,3) & ECM in space of Disse
- Loss of fenestrations & villi, dence ECM in Disse, +Kuppfer, -Hepatocytes & SINUSOIDS NARROW
Outline the causes of portal hypertension
- Compression of sinusoides from perivenular fibrosis
- Anastomoses between arterial & portal system in fibrous bands
- Reduced clearance of bacterial DNA ⇒ NO production ⇒ vasodilation of splanchnic circulation
Outline the pathophysiology of NASH
- Fat in hepatocytes (steatosis)
- +/- inflammation (steatohepatitis)
Fatty liver is usually caused by alcohol but NASH can occur.
Outline the causes of ascites
- Intravascular fluid moves into Disse due to sinusoidal hypertension & hypoalbuminaemia (↓oncotic pressure)
- Hepatic interstitial fluices moves into peritoneal cavity
- Hepatic lymphatic flow exceeds thoracic duct capacity
- High protein/ low triglycerides in hepatic lymph
- Additional sodium & water retention due to 2ndary hyperaldosteronism
What are the signs & complications of liver disease & cirrhosis?
THE COPS
-
Telangiectasis
- Spider naevi
- Terry’s nails
-
Hypoalbuminaemia
- Leuconychia
- Oedema
-
Encephalopathy (toxins unremoved)
- Liver flap
- Confusion/ coma
- Constructional apraxia (draw 5 pointed star)
- Cerebral oedema
-
Coagulapthy
- ↓F2, 7, 9, 10 ⇒ ↑INR
-
Oestrogen issues
- Hypogonadism & gynacomastia
- Palmer erythema (local vasodilation)
-
Portal hypertension & portosystemic shunting
- Ascites
- Splenomegaly
- Varices
- Caput medusae (umbilical veins)
- Fetor hepaticus
- SUN YELLOW! - Jaundice (hyperbilirubinaemia) & SBP/ Sepsis
- Hepatorenal & Hepatopulmonary Syndrome
Outline blood tests you would perform and what each indicate in suspected liver disease
-
Hepatocellular damage
- ↑ALT - specific to liver (ALT< strong=””>, otherway in Hepatitis/ NAFL)<>
- ↑/- AST - not specific
-
Cholestasis
- ↑/- ALP
- ↑/- Bilirubin - reduced hepatic metabolism by UDP-glucuronyl transferase
- ↑/- GGT - esp in chronic alcohol
-
Impaired synthetic function
- ↓Abumin - protein made by liver
- ↑INR - coagulopathy
-
Hypersplenism
- ↓platelets
- ↓WCC
Outline the pathogenesis of oesophageal varices
- Portal hypertension
- Compression of sinusoides from perivenular fibrosis
- Anastomoses between arterial & portal system in fibrous bands
- Reduced clearance of bacterial DNA ⇒ NO production ⇒ vasodilation of splanchnic circulation
- Portal pressure >10mmHg ⇒Varices
- >12 ⇒ Bleeding risk!
Outline Hepatorenal Syndrome (HRS)
- Definition
- Pathophysiology
- Types of HRS
Definition
- Cirrhosis + Ascites + Renal failure = HRS
Pathophysiology
- Inadequate hepatic breakdown of vasoactive substances
- ⇒Splanchnic & systemic vasodilation
- Splanchnic: also caused by BØ translocation, cytokines & mesenteric angiogensis
- ⇒Renal vasoconstriction
- Altered renal autoregulation
- ⇒Kidney percieves hypovolaemia → +RAA axis → A2 activated NaK → Water reabsorption & hyperosmolar urine
- →Worsens portal hypertension
Types
-
HRS1
- Rapidly progressive deterioration in circulatory & renal function (median survival 2wks)
- Treatment: Terlipressin replenishes hypovolaemia → Haemodialysis
-
HRS 2
- Steadier deterioration (survival ~6months)
- Treatment: Transjugular intrahepatic portosystemic stent shunt
Treatment
- Other than immediate management for HRS1 & 2, the only definitive treatment for both is liver transplant
Outline Hepatopulmonary Syndrome pathophysiology
- Pulmonary vasoconstriction
- ⇒Hypertension
- ⇒Anastomoses & shunting
Outline Hepatic Encephalopathy pathophysiology
Pathophysiology
- Nitrogenous waste (as ammonia) builds up in circulation and passes to the brain
- Astrocytes clear it (by processes converting glutamate to glutamine)
- Glutamine causes osmotic imbalance & a shift of fluid into these cells
- ⇒ Cerebral oedema
Outline Hepatic Encephalopathy grading
- Altered mood/ behaviour; sleep disturbance, dyspraxia (constructional apraxia), poor arithmetic, no liver flap
- ⇈drowsiness, confusion, slurred speech +/- liver flap, inappropriate behaviour
- Incoherent; restless; liver flap; stupor, no coma
- Coma
Outline Hepatic Encephalopathy diagnosis
Diagnosis
- Liver flap
- GCS
- Draw 5-pointed star (constructional apraxia)
- ⇈Ammonia
- EEG: ⇈Amplitube ⇊Frequency Triphasic waves
- CT/ MRI exclude other causes
Outline Hepatic Encephalopathy treatment
- Lactulose/ bowel enemas: draws water & nitrogen from gut
- Antibiotics: Neomycin to reduce ammonia-forming colonic bacteria
- Flumazenil (benzodiazepine antag)
- 20º head up tilt
Outline differentials of Hepatic Encephalopathy
- Hypoglycaemia
- Sepsis
- Trauma
- Post-ictal
What investigations would you perform in suspected cirrhosis?
- LFTs
- Liver ultrasound & duplex
- Liver biopsy (confirms)
- Endoscopy for varices
What is Spontaneous Bacterial Peritonitis & how do you diagnose it?
Complication of Liver Failure.
Ascitic tap finding Neutrophils >250/mm3
Outline King’s College Hospital criteria for liver transplantation in Paracetamol induced liver failure
If tha patient has;
- Aterial pH <7.3 24hr after ingestion
Or all of;
- Prothrombin (PT) >100s
- Creatinine >300umol/L
- Grade 3/4 encephalopathy
Outline King’s College Hospital criteria for liver transplantation in non-paracetamol liver failure
If the patient has;
- Prothrombin time (PT) >100s
Or 3/5 of the following;
- Drug induced liver failure
- Age <10 or >40yrs
- >1wk from 1st jaundice to encephalopathy
- PT >50s
- Bilirubin >300umol/L
Outline the indications and contraindications for liver transplant in Chronic Liver Disease
Indications;
-
Advanced cirrhosis
- ALD, HBV, HCV, autoimune, PBC, PSC, Wilsons, a1-antiT def.
-
Hepatocellular cancer
- 1 nodule <5cm or 2/3 nodules <3cm
Contraindications
- Extrahepatic malignancy & multiple tumours
- Severe cardiorespiratory disease
- Sepsis
- HIV
- Non-compliance with drug therapy
How do you manage cerebral oedema in liver failure?
ITU
- 20% Mannitol IV
- Hyperventilate
How do you manage ascites in liver failure?
- Restrict fluid
- Low-salt diet
- Diuretics
How would you manage spontaneous bacterial peritonitis (SBP)?
- MC&S
- Cefotaxime or tazocin for 5d/ until sensitivities known
- +Metronidazole if recent instrumentation to ascites
- Prophylactic to high risk patients: Norfloxacin