Liver Failure (2)

Question 1

What’s the difference between Acute and Chronic Liver failure?

What are its causes?

Answer 1

➊ Onset of liver failure (hepatic encephalopthy and coagulopathy) in those w/o a hx of liver disease (acute) and with a hx of liver disease (chronic)

➋ • Alcohol
• Infections - Hep B and C, Yellow fever
• Drugs - Paracetamol OD, Isoniazid
• Toxins - Certain mushrooms
• Vascular - Budd-Chiari syndrome
• Other - Alcohol, Fatty liver disease, Primary biliary cholangitis, Haemochromatosis, Wilson’s disease, malignancy

Question 2

How does it present?

What’s the pathophysiology behind the hepatic encephalopathy?

What can be measured in the ascitic fluid?
→ What information does this give?

Answer 2

➊ * Hepatic encephalopathy
* Abnormal bleeding
* Jaundice
* Ascites
* Fetor hepaticus (breath smells like pear drops)
* Liver flap
* Signs of CLD

➋ * In liver failure, ammonia builds up. Astrocytes in the brain clear it by changing it to glutamine.
* The excess glutamine affects the osmotic balance, leading to cerebral oedema

➌ SAAG (Serum Ascites Albumin Gradient)
→ * < 1.1 = Ascites is due to portal hypertension e.g. cirrhosis, CHF, portal vein thrombosis
* > 1.1 = Ascites is NOT due to portal hypertension e.g. peritoneal cancer, malignancy, nephrotic syndrome

N.B. In portal hypertension, the raised hydrostatic pressure forces water out into the peritoneal cavity whilst albumin remains in the vessels, therefore resulting in a higher difference in the albumin concentration between the serum and ascitic fluid.

Question 3

How is it investigated?

What is its most common complication?
→ How does it present?

What are its other complications?

Answer 3

➊ * Bloods - FBC, U&E, LFT, Albumin, INR, Glucose, Paracetamol levels, Hep screen, a1-antitrypsin
* Peritoneal tap if ascitic, checking for SBP
* Blood and Urine MC&S
* Abdo USS

N.B. PT/INR is the best test to demonstrate the synthetic function of the liver.

➋ Infection
→ Atypically, with no fever or raised WCC

➌ * Cerebral Oedema ± raised ICP
* Bleeding
* Hypoglycaemia

Question 4

How is it managed?

Which drugs are important to avoid/stop in these cases?

Answer 4

➊ * Treat the underlying cause
* Monitor obs closely including blood glucose
* For hepatic encephalopathy:
‣ Lactulose to help gut excretion of ammonia
‣ IV mannitol to reduce cerebral oedema
* For coagulopathy - Vit K and FFP
* SBP - Abx
* Liver transplantation may be needed

➋ Those that carry a risk of precipitating hepatic encephalopathy. The 3 main categories of these are:
* Drugs with a sedatives effect, due to increased sensitivity to them in liver disease
* Drugs that cause constipation, which can increase production and absorption of ammonia from the GIT e.g. codeine
* Drugs that cause hypokalaemia, because this interferes with the renal handling of ammonium ions e.g. furosemide