Liver Failure Flashcards
(23 cards)
What is encephalopathy?
Impairment of brain function caused by high levels of toxins in the blood
What is often the cause of death after liver failure?
Rapid death from:
- bleeding
- encephalopathy
What is a common cause of acute liver failure?
Paracetamol overdose
What disease is often caused by chronic liver failure ?
Cirrhosis
What other diseases can chronic liver failure result in?
Primary liver cancer
- can follow cirrhosis
Secondary liver cancer
- metastases
- from bowel tumours
Briefly describe cirrhosis
Mixed picture of damage, fibrosis and regeneration of liver structure
What is the aetiology of cirrhosis?
- Multifactorial aetiology:
- alcohol
- primary biliary cirrhosis
- viral disease (chronic active hepatitis)
- autoimmune chronic hepatitis
- haemachromatosis
- cystic fibrosis
What are signs and symptoms of cirrhosis?
- None - large and small liver (inflamed or shrunk)
- Acute bleed - portal hypertension
- oesophageal varices - Jaundice
- Oedema and as cites (abdominal fluid)
- Encephalopathy
- Spider naevi, palmar erythema
- caused by high oestrogen levels from reduced metabolism
What is as it’s and what is it’s cause?
Accumulation of fluid in the peritoneum
- caused by high portal venous pressure
- caused by low plasma protein synthesis (=lower oncotic pressure)
What are oesophageal varices?
Dilated and fragile veins that protrude into the lumen of the oesophagus - easy to rupture and can lead to catastrophic bleed
What causes oesophageal varices
- Blood entering the portal system has no exit route as portal vein can not communicate with the hepatic vein
- due to disordered portal triads in liver cirrhosis
Blood engorges as it passes through vessels at the end of the embryological gut - lower oesophagus - getting from the portal vein to systemic circulation
What synthetic functions are lost in liver failure?
- Plasma proteins
- transporting proteins
- gamma globulin - Clotting factors
What metabolic functions are lost in liver failure?
- Drug metabolism (especially 1st pass)
- Detoxification
- Conjugation of RBC breakdown products
What are common liver function tests?
- Traditionally use hepatic cell enzyme levels
- ALT, GGT (raised levels in liver inflammation, however not always accurate)
- proportional to the number of hepatic cells (falls in end stage liver disease)
- Internalised Normal Ratio (INR) most useful
(Based on synthesis of clotting factors, more accurate at assessing liver function)
What does INR measure?
Time for prothrombin to form thrombin
- compared to a control (volunteer)
What are considered normal INR values?
- Normal value is 1.0
- On warfarin ranges between 2.0 - 4.0
If INR is not 1.0 then there is significant liver synthetic dysfunction (I.e. not enough clotting factors)
What are the effects of liver failure?
- Fluid retention - ascites
- Raised INR and prolonged bleeding
- 1.3 is high for non warfarin patient - Portal hypertension
- inability of GI blood to re-enter the vena cava
- leads to oesophageal vein dilation (varices) - Inability to remove ‘waste’ - urea
- encephalopathy - Build up of haem breakdown products - jaundice
What are treatment options for liver failure?
- Supportive
- end stage disease
- acute failure - recovery likely if patient is kept alive - Transplantation
- only ‘cure’ possible - Artificial liver systems
- molecular adsorbent recirculating systems (MARS)
How many can theoretically benefit from one liver transplant and why?
3 - because the liver has 3 lives which can be divided and will restore good liver function in multiple patients
How does hepatic disease relate to dentistry ?
- Need to ensure adequate blood clotting for procedures that cause bleeding
- Need to be aware of drugs prescribed to avoid unnecessary damage and side effects
Very important to liase with physician: INR level is very useful
- End stage liver disease
- clotting factors
- abnormal drug metabolism - Suitable analgesics and sedatives
What protein can be measured to assess liver function
Albumin
What is the main function of albumin?
Helps maintain oncotic blood pressure
What part of the blood can be transfused into patients to allow blood clotting for extraction?
Plasma