patho chapter 38: liver diseases

where is the liver located?

right upper quadrant

what is unique about the liver's blood supply?

it has a dual blood supply (portal circulation and hepatic artery)

what other system is associated with the liver?

lymphatic drainage system

what is the primary function of the liver?

secretion of bile salts for fat digestion

how does the liver assist with nutrients as a digestive organ?

it processes and stores fats, carbohydrate, and proteins absorbed by the intestines

what role does the liver play in handling vitamins and minerals?

it processes and stores vitamins and minerals

what is the liver's primary function as an endocrine organ?

metabolism of glucocorticoids, mineralocorticoids, and sex hormones

true or false-the liver as an endocrine organ also regulaes carbohydrate, fat, and protein metabolism

true

what is the primary hematologic function of the liver?

temporary storage of blood

how does the liver handle bilirubin?

it removes bilirubin from the blood stream

what is the liver's role in blood cell production during certain disease states?

hematopoiesis

how does the liver contribute to blood clotting?

it synthesizes blood clotting factors

how does the liver excrete waste products through bile?

excretion of bile pigment and cholesterol via bile

what compound does the liver synthesize for nitrogen waste excretion?

urea

how does the liver handle drugs and foreign substances?

detoxifies drugs and foreign substances

true or false-the liver filters the blood

true

what is the function of bile?

emulsify fats by physically breaking large fat globules into smaller ones

what type of discoloration is a common sign of hepatocellular failure?

jaundice

what are the 4 types of jaundice?

prehepatic, hepatic, posthepatic, or cholestatic

how does hepatocellular failure affect muscle mass?

leads to muscle wasting

what fluid-related condition can result from hepatocellular failure?

ascites

how does hepatocellular failure impact blood clotting?

causes excessive bleeding due to impaired synthesis of clotting factors

what nutrient-related deficiencies occur with hepatocellular failure?

blood protein and vitamin deficiencies

how does hepatocellular failure affect glucose levels?

causes glucose imbalance

what hormonal issue arises due to hepatocellular failure?

impaired hormone production

what is portal hypertension?

increased pressure in the portal venous system

what causes portal hypertension?

impaired blood flow through the liver due to increased resistance from fibrosis and degeneration of liver tissue

what causes impaired blood flow through the liver?

increased resistance from fibrosis and degeneration of liver tissue

what is a common consequence of portal hypertension?

gastroesophageal varices

what is the primary cause of esophageal varices?

portal hypertension

what is a major cause of portal hypertension?

cirrhosis

what is cirrhosis often caused by?

chronic alcoholism, viral hepatitis, or chronic infection with the schistosoma species of liver fluke

what is a liver fluke?

type of parasitic flatworm that can cause schistosomiasis

what is hepatic encephalophathy?

complex neuropsychiatric syndrome characterized by symptoms ranging from mild confusion and lethargy to stupor and coma, often due to liver dysfunction

how is is hepatic encephalopathy graded?

from 1-4, with increasing severity

what serious complication can occur in grade 3 or 4 hepatic encephalopathy?

cerebral edema

what does cerebral edema result from?

increased intracranial pressure

what are 3 complications of advanced liver disease?

ascites, spontaneous bacterial peritonitis, and hepatorenal syndrome

what is ascites?

pathologic accumulation of fluid in the peritoneal cavity

what is spontaneous bacterial peritonitis?

infection of ascitic fluid by a single organism, unrelated to bowel perforation or surgical procedures

what are common organisms that cause spontaneous bacterial peritonitis?

streptococcus pneumoniae and escherichia coli

what is hepatorenal syndrome?

type of functional renal failure caused by severe liver disease

how is the type and stage of viral hepatitis determined?

serologic testing

what is acute viral hepatitis?

inflammation of the liver parenchyma, often caused by viral infection

what is hepatitis A?

RNA virus that is spread through enteric means (fecal-oral route)

what is hepatitis B?

partially double-stranded DNA virus that can cause liver inflammation

what is hepatitis C?

single-stranded RNA virus belonging to the flaviviridae family

what is hepatitis D (delta)?

incomplete viral organism that requires the presence of Hepatitis B (HBV) for replication

what does hepatitis D require for replication?

presence of HBV (hepatitis B virus)

what is hepatitis E?

RNA virus spread via the fecal oral route

what is chronic hepatitis?

liver inflammation that lasts 6 months or more

what is chronic persistent hepatitis also called?

triaditis or transaminitis

what is chronic peristent hepatitis?

chronic, low-grade liver inflammation of any cause

what is chronic active hepatitis?

progressive, destructive inflammatory disease that extends beyond the portal triad to the hepatic lobule and can range from mild to severe

what is autoimmune hepatitis?

progressive liver inflammation characterized by the presence of several distinctive autoantibodies and polyclonal hypergammaglobulinemia

what is biliary cirrhosis the end result of?

ongoing inflammation of the bile ducts

what does persistent biliary obstruction result in?

liver inflammation, scarring, and obliteration of the bile ductules

how are biliary flukes diagnosed?

serial stool examinations for parasitic ova and serologic testing

what are biliary flukes?

parasitic worms that affect the bile ducts

what is primary sclerosing cholangitis?

autoimmune condition resulting in chronic thickening of the bile duct walls

primary sclerosis cholangitis is commonly seen in patients with what condition?

ulcerative colitis

what is alcoholic fatty liver also called?

alcoholic steatohepatitis

what is alcoholic fatty liver?

accumulation of fat in liver cells

what causes the accumulation of fat in liver cells in patients who have alcoholic fatty liver?

excessive delivery of fat to the hepatocyte or defects in fat metabolism within the cell

what is alcoholic hepatitis?

active inflammation of the centrilobular region of the liver

what is alcoholic hepatitis characterized by?

hepatocyte necrosis with neutrophilic infiltration and mallory bodies (intracellular inclusions)

what are mallory bodies?

damaged cytokeratin (intermediate) filaments that accumulate in hepatocytes in alcohol-mediated damage

what is hereditary hemochromatosis?

disease caused by a mutant HFE gene, which allows excessive and uncontrolled iron absorption by the GI tract

what does hereditary hemochromatosis allow for?

excessive and uncontrolled iron absorption in the GI tract

what is wilson disease?

rare autosomal recessive disorder where excessive copper accumulates in the liver and other organs

what is responsible for 39% of cases of acute hepatic failure in the united states?

acetaminophen poisoning

what is acetaminophen poisoning?

overdose of acetaminophen

how much acetaminophen causes potential liver damage?

acute ingestion of 140 mg/kg or more can overwhelm detoxification pathways and damage the liver

is oral acetaminophen slowly or rapidly absorbed and metabolized?

rapidly absorbed and metabolized

what toxic metabolite is formed in acetaminophen poisoning?

N-acetyl-p-benzoquinone imine

how is the toxic metabolite of acetaminophen detoxified?

detoxified by glutathione in the liver

what happens when acetaminophen overdose overwhelms detoxification?

leads to hepatic necrosis (liver cell death)

what are common causes of liver abscess?

ascending cholangitis, intra-abdominal infections, hematogenous seeding

what should be suspected with trauma to the upper abdomen?

hepatic trauma

true or false-damage or injury to the liver should be suspected when any upper abdominal or lower chest trauma is sustained

true

true or false-when hepatic trauma occurs, blood loss can be massive

true

what types of trauma can cause serious injury to the liver?

blunt trauma and penetrating trauma

true or false-malignancy can be primary or secondary

true

in the united states, is primary malignancy rare or more common?

rare in the united states

what types of primary liver malignancy (tumors) are there?

HCC, cholangiocarcinoma, angiosarcoma, and hepatoblastoma

what is the most common primary liver tumor in children?

hepatoblastoma

what is secondary malignancy?

cancer that has spread to a secondary site, such as the liver

true or false-the liver is a common site for metastasis from primary cancers of the esophagus, stomach, colon, rectum, breast, and lung

true

how many liver transplants are done annually?

about 8,000,, although the waiting list contains approximately three times that number

what is evaluated in liver transplant patients?

physiologic and psychological evaluation

what is the main post-transplant management?

immunosuppression to prevent rejeciton, managing side effects, managing infections

when does liver transplant rejection typically occur?

post-op days 4 to 10

what are clinical manfiestations of acute liver transplant rejection?

-tachycardia

-fever

-RUQ or flank pain

-diminished bile flow through T tube drain

-change in bile color

-increasing jaundice

true or false-physiologic jaundice of the newborn is a harmless condition lasting up to 2 weeks after delivery

true

when is hyperbilirubinemia considered abnormal in newborns?

if bilirubin > 5 mg/dL on day 1, > 10 mg/dL on day 2, or > 13 mg/dL at any time

how does HAV (hepatitis A virus) affect children?

usually mild or asymptomatic, with prevalence related to sanitation

true or false-an acute hepatitis A virus infection's prevalence correlates inversely with the quality of sanitation and hygeine

true

what are examples of congenital liver diseases in children?

enzyme deficiencies, bilirubin metabolism disorders, inborn errors of metabolism, cholestatic condition (intrahepatic and extrahepatic)

true or false-some drugs may have a prolonged serum half life

true

what liver conditions are more common in older adults?

hepatocellular carcinoma and ischemic hepatitis