PH2113 - GI 2 Flashcards
What is the function of the liver?
- Central to maintenance of homeostasis.
- Storage, Clearance, Filtration, Secretion, Excretion, Synthesis, Metabolism, Homeostasis.
- detoxification of:
- endogenous and exogenous substances
- cellular debris and invading bacteria (Immune system),
- Removal of bilirubin (break down of RBC)
- Hormone deactivation
What are the classifications of liver disease?
Acute:
-less than 6 months
-Often resolves spontaneously, self limiting ( ultimately resolving itself without treatment.)
-Rapid decline in liver function
-May be asymptomatic
100% association with encephalopathy (means disorder or disease of the brain) and coagulopathy
Can result in acute liver failure (ALF)
Chronic: -Over six months duration -Often symptomatic -Secondary to long-standing cell damage -Permanent structural change -Loss of normal liver architecture -Cirrhosis (Fibrous scars Divides the liver into nodules)
Causes of liver disease:
- Viral infection:
- Hep A-/E- transmission through fecal infection/ contamination of food and water.
- Hep B/C- Blood to blood needle contamination
- Hep D- have to have Hep B to get it. - Alcohol:
- most common cause in western world.
- will lead to cirrhosis (fibrous tissue in the liver), which increases resistance to blood flow from the Hepatic portal vein resulting in portal hypertension (PHT)
- Liver cells die = liver failure
- Rate of progression (and regression) linked to further alcohol consumption - obesity, diabetes and metabolic syndrome causes:
- Non-alcoholic steatohepatitis- alcoholic liver disease symptoms, but occurs in people who drink little or no alcohol
- Non-alcoholic fatty liver disease- build-up of fat in the liver. It’s usually seen in people who are overweight or obese. - Cholestasis (reduction or stoppage of bile flow.) :
Intra-hepatic
Extra-hepatic - Immune disorders
- Vascular abnormalities
- Metabolic disorders
- Genetic disorders
9. Drugs: 2 types: Type A: -Related to the dose of the drug -Withdrawal of precipitating drug results in reversal e.g. paracetamol (NAPQI) Type B: - related to the property of the drug. - To do with hypersensitivty or how its metabolised
What are some signs of drug induced liver disease?
Signs and symptoms similar to other causes of liver disease
History of exposure is best marker
Onset can be acute
Fever, chills, rash, pruritis, abdominal pain, n+v
Overt symptoms may develop over time
What are the risks of drug induced liver disease?
Race Age Gender Alcohol consumption Pre-existing liver disease Genetics
How is drug induced liver disease managed?
Withdraw causative agent Inform patient Avoid future exposure Acute patients Avoid physical exertion, alcohol, paracetamol and hepatotoxic agents Supportive management
What is paracetamol overdose?
- Rapid deterioration in liver function in a previously healthy individual
- Complicated to manage because:
CNS, CV and renal systems affected
Infection and bleeding can be life threatening
-20-30 tablets consumed within 24hours can result in severe hepatocellular necrosis
Saturation of glutathione dependent pathway
What are the stages in paracetamol toxcity?
> 1 hour- activated charcoal is used to treat since it absorbs the paracetamol- no harmfull effects.
2-24hrs - asymptomatic or non-specific signs.
8 Hours- N acetylcysteine- effective
24-48hrs - RUQ pain, jaundice, deranged bloods.
>72hrs - jaundice, somnolence, liver failure
Results in
Cerebral oedema
Shock
Sepsis
Renal failure
What are the non specific symptoms of liver disease?
- Weakness, fatigue, general malaise
- Chronic - weight loss, anorexia
- Advanced - loss of muscle bulk
- Abdominal discomfort/pain
- Jaundice- yellowing of the skin
- Increase in the size of the liver
What are some cutaneous signs of liver disease?
Hyperpigmentation
Scratch marks
Spider naevi
What are some abdominal signs of liver disease?
- Distension- enlargement/ballooning effect of the liver
- Hepatomegaly (abnormal enlargement of the liver.)
- Splenomegaly (abnormal enlargement of the spleen.)
- Umbilical and paraumbilical veins- increase in venous pressure, because volume of blood moving through the veins changes.
What are signs of liver disease?
- Jaundice- yellowing of skin
- Pruritus: itchy skin because of the deposition of bile salts.
- Portal hypertension: Increase in BP in veins.
- Ascites- Swelling of the abdominal cavity die to fluid.
What is jaundice and how can it be treated?
- Sign of liver disease but non specific to liver disease.
- Yellowing of sclerae, skin
- Hepatocellular
- Cholestatic (bile cannot flow from the liver to the duodenum)
- Prehepatic (Increased blood breakdown)
What is pruritus and how can it be treated?
- Itchy skin because of deposition of bile salts in the skin.
- Most debilitating in cholestatic conditions- Obstruction relieved by endoscopy, radiology, surgery
Treatment (several treatments):
- Anion exchange resins e.g. cholestyramine, colestipol
- Bind bile acids and prevent reabsorption
- helps body remove bile acids which can lower cholesterol levels in the blood.
- Side effects : GI (constipation, diarrhoea, flatulence), fat and vitamin malabsorption
- Poor adherence due to palatability
Counselling patients on taking drug
Take interacting drugs 1hr before or 4hrs after cholestyramine
Benefits may take up to one week to become apparent
- Antihistamines
- Sedating properties useful if pruritus affects sleep - Ursodeoxycholic acid
- Topical therapies: Calamine lotion, menthol 2% in aqueous cream
What is portal hypertension?
- increase in the blood pressure of veins leading to:
- collateral vein formation (re-routing of blood circulation around a blocked vein).
- shunting of blood to systemic circulation
Contributes to:
- Formation of ascites (accumulation of fluid in the peritoneal cavity, causing abdominal swelling).
- Development of encephalopathy (disorder of the brain).