Liver: case studies Flashcards
Cholestatic enzymes
GGT (gamma-glutamyl transferase) and ALP (alkaline phosphatase)
This often indicate a mass or biliary obstruction
Inflammation enzymes
ALT (alkaline-transferase) and AST (aspartate-transferase)
What causes jaundice?
Elevated bilirubin. causes yellow sclera and skin.
Due to a biliary obstruction (bile release), or hepatocellular injury (lysis)
Haemolysis also causes bilirubin
What measure the livers synthetic function
Prothrombin Ratio (clotting factors) Albumin
What measure the livers detox function
NH3 ammonia levels, if not detoxified they can build up in the brain > hepatic encephalopathy
If the AST and ALT are really high, what is the much common cause to look at first?
Viral infection, most commonly Hep A, B, C
Why should you be worried about blood transfusions pre 90’s
Because there wan’t the regulations there are now, so potentially carrier of infection. eg) hep B and C
Chronic Hepatitis A
Doesn’t exist, Hep A is benign and self-limiting
How do you determine if viral hepatitis is acute of chronic
Acute: first 6 months
Chronic: post 6 months
Causes of Hep B and Hep C, how are they transmitted, what do they cause and available treatment?
Causes of Hep B: *** sexually transmitted drug use mother to child horizontal transmission
Causes of Hep C ***Drug use blood transfusion low sexual transmission risk mother to child occupational tattoo
Both transmittable through blood
Can lead to cirrhosis and hepatocellular carcinoma (if aqquired later some Hep B patients will resolve)
There is a vaccine for Hep B but not Hep C (incurable)
Interferon
Old drug for HCV, many adverse side -effects, low success rate (50%), a cytokine so gives flu like effect.
-given as a sub-cutaneous injection
Initially alone
the interferon + ribavirin
Breakthrough HCV treatment
Direct-acting Antiviral agents
-tablets
- Cure rates >90%
Been the cause of declining need for liver transplants
Oesophageal/ gastric Varices
Due to pressure increase due to portal hypertension (associated with cirrhosis), these are dangerous as they have potential to bleed.
Treatments: ‘Banding’, suck varices up into a cap, rubber band strangles varices and stops the bleeding
This may need to be done several times, but they can REFORM, so it’s only temporary!
Portal circulation consists of?
Portal Vein: that drains nutrient rich blood from the GI tract and spleen to the liver
venous blood passes through the
Liver > IVC > heart
Portal Hypertension
High pressure in the portal vein, more resistance making it harder for blood in the portal circulation to return to the heart.
Portosystemic shunts/collaterals form, that enlarge and try to divert blood away from the portal system to the heart > varices
Two most common place to get varices
1) Gastro-oesophageal Junction: work upwards
2) Stomach: particularly fundus
Normal Portal BF vs Cirrhosis (Portal hypertension)
BP: 55mmHg
Supplies 3/4 Blood flow to liver (70% O2)
100% blood > hepatic vein > systemic circulation
BP: 12mmHg
portosystemic shunts formed > varices
Liver intitially ______ then progressively ______
Liver intitially elarged then progressively shrinks
Is fibrosis reversible?
Potentially if the liver is allowed time to regenerate by removing inflammatory cause. If this doesn’t occur»_space; cirrhosis ‘irreversible scarring’
What causes fibrosis
repeated bouts of inflammation
Can the liver function with cirrhosis?
When it is mild, as the liver is good at compensating, huge reserve capacity. However as it progresses more and more function is lost (liver failure at 80-90%)
Hepatic Encephalopathy. Early and late symptoms
Build up of NH3 toxins in the brain due to liver failure. THe liver is unable to detoxify substances from the bacterial metabolism. Also portosystemic shunts bypass the liver entirely (no detox at all). You get a build up of ammonia in the blood (passes blood-brain barrier)
Early Symptoms: mood and personality change. Inverted sleep pattern. (hard to diagnose)
Late Symptoms; Confusion and bizarre behaviour, drowsiness and coma.
Treatment of HE
Lactulose
- normally a laxative to treat constipation
- decrease ammonia production by bacteria
- makes it a non-absorbable substance > excreted
For management but not definitive treatment.
Ascites
fluid accumulation in the peritoneum > abdominal distention.
Often caused by portal hypertension
-Elevated hydrostatic pressure in PV > fluid moves out of circulation
-Low oncotic pressure in PV (low serum albumin) unable to hold onto fluid
Hypersplenism
1) Splenomegaly : swollen spleen
2) Low platelet count: platelets going through spleen are destroyed at a higher rate
People can donate upto _____% of their liver
50%
Definitive treatment for liver failure
Liver transplant
Acute thrombosis of Hepatic veins
Budd-Chiari
- outflow of blood from liver obstructed
- liver becomes congested > hepatocellular damage
- Results in PH with ascites forming
Fulminant
very severe and sudden
Causes of Budd-Chiari
75% no obvious cause 25% cause identifies -tumor -pregnancy -Contraceptive pill -clotting disorders
Management of Budd-Chiari
Portocaval shunting to divert blood flow
- TIPSS (transjugular intrahepatic portosystemic shunt): reduces resistence of BF to liver, done for PH
- surgical
Anticoagulation : thin blood and dissolve clot
Diuretics
