Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
27 Cards in this Set
- Front
- Back
|
MECHANISM: Jaundice
|
Failure of metabolism or excretion of bile
= Yellow colouration of tissues owing to bile paigments |
|
|
MECHANISM: Bleeding
|
Failure of hepatic synthesis of clotting factors
= Easy bruising + Prolonged clotting time of blood (↑PTT) |
|
|
MECHANISM: Oedema
|
Failure of hepatic synthesis of albumin
-> ↓ Oncotic pressure in plasma/blood vessels -> Osmosis of fluid out of blood vessels -> Extravascular swelling of water |
|
|
MECHANISM: Ascites
|
Low serum albumin + portal hypertension
-> Osmosis of fluid out of blood vessels -> Fluid in peritoneal cavity |
|
|
MECHANISM: Gynaecomastia + Testicular atrophy
|
Failure of liver to detoxify endogenous oestrogens
= Enlarged male breasts + Testicular atrophy |
|
|
MECHANISM: Hepatic Encephalopathy
|
Failure of liver to detoxify ammonia + excitatory amino acids (from protein breakdown)
= Altered consciousness, lack of coordination, may lead to coma |
|
|
MECHANISM: Haematemesis and or Melaena
|
Portal hypertension
-> Bleeding from oesophageal varices or per rectum = Vomiting blood and/or passing bloody stools |
|
|
Lab evaulation of liver disease
Name serum measurements for: Hepatocyte integrity |
Cytosolic hepatocellular enzymes:
AST, ALT, LDH |
|
|
Lab evaulation of liver disease
Name serum measurements for: Biliary system |
Bile substances:
Serum bilirubin (total, conj. and unconj.), urine bilirubin, serum bile acids Plasma membrane enzymes (from damage to bile analiculus): Serum ALP, GGT, 5’nucleotidase |
|
|
Lab evaulation of liver disease
Name serum measurements for: Hepatocyte function |
Proteins secreted into blood: Serum albumin,
PT Hepatocyte metabolism: serum ammonia, aminopyrine breath test, galactose elimination (IV injection) |
|
|
Name 5 most common patterns following hepatic injury
|
- Hepatocyte degeneration and intracellular accumulations (cell swelling; accumulation of fat/copper/iron)
- Hepatocyte necrosis and apoptosis - Inflammation (steatohepatitis, infective) - Regeneration - Fibrosis |
|
|
Describe Hepatic Failure
|
Most severe consequence of liver disease.
Result of - Sudden + massive destruction (i.e. fulminant hepatic failure) - More commonly: End-stage progression/chronic liver disease Results when 80-90% of hepatic functional capacity is lost Transplant gives best prognosis Mortality w/o transplant = 80% |
|
|
List and describe 3 causes of Hepatic Failure
|
1) Acute liver failure
Acute liver illness associated w/ encephalopathy within 6 months of initial diagnosis - Fulminant when encephalopathy occurs within ~2 wks of jaundice - Sub-fulminant if ~3 mths after jaundice Cause: Massive necrosis - Usually drug/toxin-related (e.g. paracetemol), or immune-mediated hepatocyte destruction (e.g. viral hapatitis) 2) Chronic liver disease Most common cause End-stage of relentless chronic hepatitis, ending in cirrosis 3) Hepatic destruction w/o overt necrosis Viable but dysfunctional hepatocytes (e.g. tatracycline toxicity or acute fatty liver of pregnancy) |
|
|
CLINICAL FEATURES: Liver Failure
|
Same, regardless of cause
- Jaundice: Almost inevitably occurs - Hypoalbuminemia: predisposition to peripheral edema - Fetor hepaticus: Breath smells "musty" or "sweet & sour" (Related to - GIT bacteria -> Formation of mercaptans - Shunting of splanchnic blood from portal -> systemic circulation) - Palmar erythema (Impaired oestrogen metabolism -> Local vasodilation) - Spider angiomas (Hyperestrogenamia -> Central, pulsating, dilated arteriole; small vessels radiate from it) - Gynecomastia, hypogonadism (Hyperestrogenamia) |
|
|
Life-threatenting complications of Hepatic Failure
|
Very high risk of cencephalopathy + multi-organ failure
Respiratory failure (w/ pneumonia & sepsis) Renal failure (major killer) Coagulopathy (Impaired hepatic synthesis of clotting factors) -> Can lead to MASSIVE GIT bleeding (death usu. occurs in weeks -> months) |
|
|
Define Hepatic Encephalopathy
|
Spectrum of distrubances in consciousness, ranging from
- subtle behavioural abnormalities, - to marked confusion and stupor - to deep coma/death |
|
|
Associated signs of Hepatic Encephalopathy
|
Rigidity
Hyper-reflexia Asterixis (i.e. Hepatic flap) |
|
|
MECHANISM: Hepatic Encephalopathy
|
CNS/neuromuscular dysfunction thought to be related to:
Ammonia build-up -> Impaired neuronal function + promotes brain oedema (Reversible) |
|
|
Dx: Hepatic Encephalopathy
|
Number connection tests,
line tracing tests, serial dotting test, digit symbol test, digit symbol test, block design test |
|
|
Life-threatening complications of hepatic failure:
Hepatorenal Syndrome Definition |
Renal failure in patients w/ severe chronic liver disease, with no known intrinsic causes of renal failure.
Incidence is 8%/yr in patients with cirrhosis and ascites. |
|
|
Life-threatening complications of hepatic failure:
Hepatorenal Syndrome Characteristics |
Usually precipitated by:
Infection, GIT hemorrhage, or major surgery Heralded by drop in urine output, rising BUN/creatinine, Eventually develops into: Na retention, impaired free-water excretion, ↓ renal perfusion/glomerular fltration. |
|
|
Life-threatening complications of hepatic failure:
Hepatorenal Syndrome Prognosis + Tx |
Median survival =
2 weeks (rapid-onset) to 6 months (insidious onset) Tx = Transplant |
|
|
Life-threatening complications of hepatic failure:
Hepatorenal Syndrome Major diagnostic criteria |
Hepatic failure,
portal HTN, creatinine > 1.5mg/dL or GFR <40 mL/min, no shock/ongoing bacterial infection/nephrotoxic agents or fuid losses, no improvement after diuretic withdrawal/IV saline, proteinuria, normal renal US |
|
|
Life-threatening complications of hepatic failure:
Hepatorenal Syndrome Proposed therapies |
Liver transplant,
TIPS (Transjugular intrahepatic portosystemic shunt), vasoconstrictors + albumin, renal vasodilators, renal replace- ment therapy |
|
|
Life-threatening complications of hepatic failure:
Hepatopulmonary syndrome Definition |
Clinical triad of
1. chronic liver disease, 2. hypoxemia (usually V/Q mismatch), 3. intra-pulmonary vascular dilatations (IVPD) |
|
|
Life-threatening complications of hepatic failure:
Hepatopulmonary syndrome Mechanism |
Vasoactive substances, especially enhanced NO production.
|
|
|
Life-threatening complications of hepatic failure:
Hepatopulmonary syndrome Clinical features |
↓ arterial O2 saturation and ↑ dyspnoea on moving from supine to upright.
Oxygen therapy can help Transplant is only curative treatment |
