Liver failure Flashcards
Which lobe of the liver is the gallbladder closest to?
Right lobe
What does the gallbladder do?
Stores bile produced by the liver
What does the gibsons capsule do?
Is a layer of connective tissue surrounding the liver and protecting the hepatic artery, portal vein, and bile ducts
What do kupffer cells do?
Phagocytic and macrophagic properties, engulf bacteria in the sinusoids
What is the portal triad?
1) Hepatic artery (25% blood flow)
2) Portal vein (75% blood flow)
3) Bile duct
What is the dual blood supply of the liver?
1) Hepatic artery supplies the liver with oxygenated blood, arises from the celiac artery (25% blood flow)
2) Portal vein supplies liver with deoxygenated blood (75% blood flow) from stomach, spleen, intestines, etc
What is supplied in the portal vein circulation?
Deoxygenated blood, rich in nutrients, hormones, toxins, bacteria etc
What are the functions of the liver?
Carbohydrate, protein, fat metabolism, bile formation, vitamin and mineral storage, hematological functions, detox
How does the liver metabolize carbohydrates?
Stores serum glucose as glycogen (glucogenesis)
Breakdown of glycogen (glycogenolysis)
Creates glucose from proteins, fats (gluconeogenesis)
How does the liver metabolize proteins?
Synthesis of proteins such as albumin
Breakdown of proteins into ammonia, urea
How does the liver metabolize fats?
Synthesis of phospholipids, cholesterol
Breakdown of fats into glycerol, fatty acids, ketones
What are the hematological function of the liver?
Synthesis of albumin, clotting factors (fibrinogen, prothrombin, vitamin K)
Kuffer cells filter blood to remove bacteria
What are the detoxification functions of the liver?
Deactivates hormones such as estrogen
Conjugates steroids and hormones
What is cirrhosis?
Chronic liver disease where normal liver cells and structures are altered by regenerating nodules / scar tissues that interrupt arterial, portal, and bile circulation.
Liver becomes congested with increased resistance
What 2 things does cirrhosis cause?
1) Portal hypertension
2) Ascites
What is portal hypertension?
Backup of blood into portal venous system causing vein distention in: Esophagus Intestine, stomach Spleen Umbilicus, rectum
What does vein distention due to portal hypertension cause?
Varices with risk of hemorrhage
What is ascites?
Accumulation of serous fluid in the peritoneal cavity
What causes ascites?
Portal hypertension (increased hydrostatic pressure forces fluid out of veins into peritoneum)
Hypoalbuminemia (decreased oncotic pressure causes fluid to leave blood vessels)
Impaired water excretion
What does ascites result in?
Third spacing, generalized edema, eventually causes hypovolemia
What compensatory mechanisms are activated when the body gets ascites?
Triple A:
ADH
Aldosterone
Angiotensin
Try to compensate by retaining fluid but just makes ascites worse
What is the treatment for ascites?
Albumin infusion, diuretics, abdominal paracentesis
How can GI hemorrhages be prevented?
GI prophylactics, early enteral feeding
How can GI hemorrhage due to cirrhosis be treated?
Meds to constrict splenic arteries such as vaso
Vitamin K to help clotting
Special NG tubes to tamponade the blood (usually esophageal)
What is hepato-renal failure?
Acute renal failure as a complication of hepatic failure d/t hypovolemia or impaired renal perfusion from ascites
What does hepato-renal failure cause?
Fluid overload and eventual respiratory failure
What is acute liver failure?
Severe liver damage with rapid onset (e.g. tylenol OD)
May occur with or without pre-existing liver disease, massive necrosis of hepatocytes and onset of encephalopathy
What can cause acute liver failure?
Viral hepatitis, meds, toxins, overdose e.g. Tylenol
What are assessment findings correlated to liver damage?
Hepatic insufficiency:
Ankle edema, ascites, anemia, jaundice, hemorrhagic tendency, coma or decreased LOC
Hyperestrogenism:
Testicular atrophy, gynecomastia, red palms, altered hair distribution, spider nevi
What are spider nevi and what do they represent?
Collection of small dilated arterioles clustered close to surface of the skin (web like), sign of cirrhosis and hyperestrogenism
What are assessment findings correlated to portal hypertension?
Ankle edema, ascites, splenomegaly, esophageal varices, caput medusa
Hypersplenism:
Anemia (d/t low hgb), leukopenia (increased risk of infection), thrombocytopenia (decreased platelets)
What is caput medusa and what does it represent?
Distended and engorged superficial epigastric veins radiating from umbilicus across the abdomen.
Indicates portal hypertension
Where is the spleen and what does it do?
Upper left part of abdomen.
Filters blood (affects number of RBCs, hgb, platelets), breaks down and removes cells when needed
Stores RBCs, platelets, WBCs
Important immune response function, blood clotting, RBCs
What is hyponatremia and why does it occur in liver failure?
Na < 135 mmol/L
Common finding due to diuretics or dilutional hyponatremia
Na+ is diluted due to ADH compensating for portal HTN and ascites by retaining more water.
Why is hyponatremia dangerous?
Shift of H2O intracellularly results in cerebral edema, brain compensates by moving K+ extracellularly causing hyperkalemia
Na replacement should be done slowly to allow gradual ion shift
What can occur with rapid hyponatremia correction?
Osmotic demyelination
What is circulatory failure and why does it occur in liver failure?
Caused by intravascular hypovolemia and/or systemic inflammation due to ascites, fluid 3rd spacing
How is circulatory failure d/t hepatic failure treated?
Fluid replacement and levo infusion is first line
Crystalloid infusion with albumin
Pts often on diuretics and fluid replacement at the same time
Why does infection occur with liver failure?
Liver is key autoimmune organ and processes toxins / bacteria through venous circulation
What are considerations with sedation for liver failure pts?
Sedation can worsen liver failure as they are liver-metabolized or renal metabolized.
If sedation required, non-benzos useful (propofol)
What position can help ascitic pain?
Semi-recumbent position
Why does adrenal insufficiency occur with liver failure?
Liver is unable to synthesize cholesterols required for adrenal gland to make cholesterol
Pt may need corticosteroid therapy
What does ongoing adrenal insufficiency do for pts in liver failure?
Ongoing hypotension due to inactivation of SNS
What is the normal pressure inside the abdominal cavity?
5-7 mmhg
What are assessment findings for intra-abdominal hypertension?
Hypotension Metabolic acidosis Oliguria Increase in peak airway pressure Hypoxemia Increase lactate Edema, weeping, 3rd spacing
What is abdominal compartment syndrome and how is it diagnosed?
Sustained increased abdominal pressure greater than 20mmHg and associated with new organ failure
What are the steps to get an intra-abdominal pressure reading?
1) Pressure port attached to sampling port of foley
2) System is zerod
3) Foley cath clamped
4) While pt is supine, 25 cc warmed NS is injected into the bladder, allow 30-60 secs to obtain bladder pressure reading at end of expiration
What is the grading for abdominal pressure?
Normal 5-7 mmHg Grade 1 --> 12-15mmHg Grade 2 --> 16-20 mmHg Grade 3 --> 21-25 mmHg Grade 4 --> >25mmHg
If greater than 20mmHg with new organ failure, then abdominal compartment syndrome
What is ALT (Alanine aminotransferase) and what happens during liver failure?
Enzyme found in liver, increases with injury
What is AST (Aspartate aminotransferase) and what happens during liver failure?
Enzyme found in liver, bones, cardiac muscle
Increases with injury and ALCOHOL CONSUMPTION
What is ALP (Alkaline phosphate) and what happens during liver failure?
Enzyme found in liver, biliary tract
Increases with intrahepatic or impaired bile excretion
What does total bilirubin include?
Total conjugated and unconjugated bilirubin
What happens to ALT/AST/ALP in liver injury?
Increase
What happens to total bilirubin in liver injury?
Increase
What happens to PT/PTT/INR in liver injury?
Increase
What happens to albumin in in liver injury?
Decrease
What happens to ammonia in liver injury?
Increase
What happens to hemoglobin in liver injury?
Decrease or remains normal
What is hepatic encephalopathy?
Mental confusion progressing to coma resulting from liver failure as toxins accumulate in blood and cross blood brain barrier
What is the main chemical responsible for hepatic encephalopathy?
Ammonia formed by protein breakdown by intestinal bacteria
How is hepatic encephalopathy graded and what are the clinical manifestations?
Grade 1 –> Euphoria, depression, mild confusion, slurred speech, slight asterixis
Grade 2 –> Lethargy, moderate confusion, abnormal EEG, marked asterixis
Grade 3 –> Marked confusion, incoherent speech, asterixis, sleeping but arousable
Grade 4 –> Coma, later unresponsive
What are 2 medical treatments for hepatic encephalopathy? What are other interventions?
1) Neomycin
2) Lactulose
Airway management, avoid sedatives, GI prophylaxis, vitamin K
How does neomycin work for hepatic encephalopathy?
Inhibits breakdown of proteins into ammonia, decreases ammonia in the blood
How does lactulose work for hepatic encephalopathy?
Causes ammonium to get excreted by drawing ammonia from the blood into the colon where it gets removed
