Acute Liver Failure (ALF)**** Flashcards
What are the features of acute liver INJURY?
What is the main feature distinguishing acute liver injury from acute liver failure?
How much of the liver needs to be damaged for this to happen?
What needs to be ruled out in the history to diagnose any of the above?
Biochemical evidence of liver injury/damage
Impaired liver function - (Prolonged PT for example)
Hepatic encephalopathy
2/3
No underlying CLD
Whats the time scale for the following:
Hyperacute
Acute
Subacute
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What is a major cause for hyper acute ALF?
What 2 hep viruses may cause hyper acute ALF? - 3
What else may cause it? - think collapse or AF
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What hep virus is the most likely cause of acute ALF?
Pregnancy can also cause acutE ALF!
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Non-paracetamol drug-induced is a cause of Subacute!
< 1 wk
2-4 wks
1-3 months
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Paracetamol overdose
Hep A
Hep E
Ischaemia
Causes:
Overdose - 2
Viral - 2
Pathogens - 3
Drugs - seizures med (2), ABs (2)
What is seronegative hepatitis?
Paracetamol
Alcohol - acute alcoholic hepatitis
Hep A and B
CMV
HSV
EBV
Phenytoin and sodium valproate
Nitrofurantoin and co-amoxiclav
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No cause found including Hep A, B and C
Causes - Metabolic:
2 - Wilson’s and Reye’s
What is Wilson’s disease?
What is Reye’s disease?
A rare genetic disorder characterized by excess copper stored in various body tissues, particularly the liver, brain, and corneas of the eyes.
A rare but serious disease that causes swelling in the liver and brain. It can affect people of any age, but it is most often seen in children and teenagers recovering from a virus such as the flu or chickenpox.
Causes - Vascular:
2 - Ishcaemic hepatitis and Budd-Chiari syndrome
What is ischaemic hepatitis?
What is Budd-Chiari syndrome?
An acute liver injury caused by insufficient blood flow (and consequently insufficient oxygen delivery) to the liver. The decreased blood flow (perfusion) to the liver is usually due to shock or low blood pressure.
The condition is caused by occlusion of the hepatic veins that drain the liver. It presents with the classical triad of abdominal pain, ascites, and liver enlargement.
Causes - Pregnancy:
2 - Fatty liver of pregnancy and HELLP
What are the 3 components of H-EL-LP syndrome?
HELLP stands for haemolysis (H), elevated liver enzymes (EL) and low platelet count (LP) .
It’s a serious but rare pregnancy complication.
It involves red blood cells in the blood breaking down, signs of liver damage and a low platelet count
S+S:
Non-specific - list a few - 4
Hepatic - 4
Fatigue Nausea Anorexia Weight loss ---- Abdo or RUQ pain Jaundice Pear drop smell - ketones - fetor hepaticus Hepatic encephalopathy
Investigations - Bloods:
We are investigating 3 things:
(1) Asesss disease severity
(2) Check aetiology
(3) Test for complications
(1) Assess disease severity:
What bloods would you do specifically for the liver function? - 4
What is a common finding on the FBC especially if they are a heavy alcohol drinkers?
Why do you do Hb?
Why is an ABG/VBG done?
LFTs - high Synthetic function - PT/INR - high Albumin - low Glucose - low gluconeogenesis ---- Thrombocytopenia Macrocytic anaemia
Low Hb - haemolytic anaemia in Wilson’s
To look for arterial lactate - it is a marker for severity as well
Investigations - Bloods:
(1) An ABG is done which would show acidosis. Why does this happen?
Why do you do U&E?
Reduced hepatic clearance of lactate
AKI is a potential complication or hepatorenal syndrome
Also check for urine output.
(2) Investigations for causes:
- What drugs serum levels are you going to look for?
- Infection
- What auto-antibodies can be measured? - 4
- 2 tests for Wilson’s
- Haemochromatosis
- Pregnancy
- What needs to done which isn’t in the LFT’s, but could help in working out if it is liver pathology?
- What should be measured which could be contributing to encephalopathy, which needs to be ruled out?
- Although not a cause, how could you possibly test for HCC?
Paracetamol levels
Viral serology
ANA, ASMA, AMA, ANCA
Ceruloplasmin and 24hr urine copper
Iron studies (ferritin, transferrin saturation)
Beta-hCG
AST
B12 and folate
Alpha-fetoprotein (AFP)– this should not form part of the liver screen but instead is used in screening for Hepatocellular Carcinoma – a common sequelae of Cirrhosis, and chronic Hepatitis B and C infection.
Investigations:
(2) Why do you do an abdo USS with doppler? - 3
(2) Why do you do an XR in those with reduced consciousness (hepatic encephalopathy)?
(3) Test for complications:
- What other organ is at risk of pathology with ALF?
What imaging should be done to rule out other causes of confusion?
An ascitic tap can be done and a serum to ascites albumin gradient (SAAG) can be worked out.
- What does a gradient > 11 g/L suggest the cause is?
- If it is <11g/L, then it is unlikely to be above!
Hepato/splenomegaly Cirrhosis Hepatic vein thrombosis -- Looking for aspiration pneumonia
Pancreas - so Lipase and amylase are done
CT Head
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> 11 - Portal HTN
<11
Complications:
The main one causing death
2 others
Cerebral oedema - the commonest cause of death - leads to raised ICP
Brain hypoperfusion
Coning
Sepsis and shock
AKI
Paracetamol overdose:
Can present within 8 hrs or over 3 days as it is dose dependent!!
Early features
Later features
When do most people tend to present and why?
Non-specific abdo pain
N&V
Altered clotting
Jaundice
RUQ pain
ALF
Encephalopathy
Pre-symptomatic - usually regretting OD or brought in by others
Paracetamol overdose:
Serum paracetamol level should be measured >4 hrs after ingestion. Why?
It takes some time to peak
Paracetamol overdose:
What is the first line Rx which is the antidote?
Within what window should it be given?
What is another alternative?
What can be given if it is less than 1 hr of ingestion and why?
Acetylcysteine IV or infusion - best within 8 hrs
Methionine PO - an amino acid
Activated charcoal - reduces absorption
