Chronic liver disorders Flashcards
What does chronic liver disease result from
Hepatocellular injury and necrosis often with a degree of underlying fibrosis of the liver
When does jaundice result
When the liver’s capacity to convert and excrete bilirubin as bile is exceeded
What can jaundice result from
Over production of bilirubin
reduction in the eliminatory capactiy of the liver
What is bilirubin
The breakdown product of haem
Where is bilirubin found
Bound to albumin in the plasma but at the hepatocyte membrane, it dissociates and enters the hepatocyte
What is prehepatic jaundice
increased degradation of haem leading to haem concentrations that cannot be cleared by the normal conjufative mechamisms resultin in predominately unconjugated hyperbilirubinaemia
What is hepatic jaundice
Liver damage and or inflammation affecting the conjugative and excretory ability of the liver so that the normal bilirubin load cannot be excreted. This results in a predominately unconjugated or mixed conjugated and unconjugated hyperbilirubinaemia
What is postheaptic jaundice
Obstruction of the biliary outflow tract at any level, leading to an inability to excrete conjugated bilirubin in bile resulting in a conjugated hyperbilirubinaemia
Is unconjugated bilirubin in water soluble or insoluble
Insoluble (cannot be excreted in urine)
What is conjugated bilirubin converted to in the terminal ileum
Urobilinogen
Bilirubin that is not reabsorbed is further converted to what and what does this do
Urobilin then stercobilin
It gives faeces its normal colour
What gives clues about the cause of jaundice
Observation of the stool and testing for the different byproducts of haem excretion in the blood and urine
What results in pale stool and dark urine
Obstruction of the biliary system
What is portal hypertension defined as
The gradient reaching 12mmHg or greater
What does increased pressure in the portal system result in
Collateral vessel formation Ascites increased risk of hepatorenal syndrome hepatic encephalopathy Splenomegaly
What is the management for portal hypertension
First line is with a non-selective B blocker: propanolol to reduce the pressure within the portal system
What is ascites
The presence of fluid in the peritoneum
What are the two main pathogenic mechanisms for asictes
Transudation and exudation
What are transudates:
Hydrostatic: result of portal hypertension and resultant increases in the pressure in splanchnic vessels
Oncotic: the result of lowered serum albumin as the synthetic function of the liver decreases
Fluid retention: renal hypoperfusion resulting from portal hypertension causes release of renin and hence a secondary hyperaldosteronism; this results in salt and water retention and contributes to ascites
What are exudates
They result from an inflammatroy or neoplastic process at the peritoneal surface causing increased production of peritoneal secretions
What is the function of the Serum-to-ascites albumin gradient
To determine whether ascites is related to transudation or exudation
How is SAAG calculated
Serum albumin conc. - Ascites albumin conc.
What is the general management of ascites
treat the underlying liver condition
Improvement of nutritional status in order to maximise serum albumin
What are the specific management for asicties
Reduction of hydrostatic pressure in the splanchnic vasculature with diuretics - spironolactone!
Abdominal paracentesis - removing the fluid through a drain
What is intractable ascites
Ascites not responding to aggressive diuretic use
What are the options for Intractable ascites
Repeated paracentesis
Radiological placement of intraheaptic portal venous hunts to reduce splanchnic pressure
What is spontaneous bacterial peritonitis
The spontaneous onset of bacterial infection of ascitic fluid in the setting of liver disease
What are the majority of the causative organisms in spontaneous bacterial peritonitis
Gram negative
What are the investigation required to diagnose SBP
paracentesis and identification of ascitic neutrophils
Gram stain and culture of ascitic fluid
What is the management of SBP?
Empiric therapy is with IV cephalosponins but may be guided by past culture and IV albumin
What do varices result from
Collateral flow from the portal system through the coronary vein of the stomach in the azygous vein
Where do varices lie
Submucosally
What are varices graded by
According to their size and the presence of overlying mucosal lesion
What is the management for varices
Primary prophylaxis - following diagnosis of varices but proper to the development of a bleeding complication
Secondary prophylaxis - instituted after an episode of bleeding
What is the current favoured initial treatment for primary prophylaxis
Beta blockers
What is the modality of first choice
Band ligation
What are some second line modalities
Sclerotherapy
splanchnic vasoconstrictors
When does hepatic encephalopathy result
When toxic metabolites cannot be excreted by the diseased liver; they bypass the liver due to portosystemic shunts and produce direct effects on the brain
When does hepatic encephalopathy result
When toxic metabolites cannot be excreted by the diseased liver; they bypass the liver due to portosystemic shunts and produce direct effects on the brain
What is the management of hepatic encephalopathy
Correction or reduction in factors that precipitate the onset of encephalopathy
Non-digestable disaccharides (lactulose)
Reduction of protein in the diet may be reasonable in the short term
What is hepatorenal syndrome
Renal dysfunction in chronic liver disease
Who does hepatorenal syndrome occur in
Patients with chronic or acute liver disease
What are the 2 classes of hepatorenal syndrome
Early and late (type 1 and type 2)
How is the diagnoiss of HRS made
Through exclusion
What is the management of HRS
Correcting reversible factors:
Hypovolaemia
Infection
Presence of nephrotoxins
What is the only definitive treatment for HRS
Liver transplantation
What is hepatopulmonary syndrome
Pulmonary dysfunction in association with chronic liver disease
What is the common complaint from patients with hepatopulmonary syndrome
Shortness of breath
What 3 things does the diagnosis of HPS rely on
The demonstration of:
liver disease or portal hypertension
Elevated age-adjusted alveolar-arterial oxygen gradient AaPO2
Evidence of intrapulmonary vasodilatation
What is involved in the management for HPS
Liver transplantation
Oxygen supplementation
