Liver Systemic Effects & Diseases Flashcards
What are the Cardiovascular Effects of Liver Dysfunction?
Hyperdynamic circulatory state.
-Unable to get rid of toxins, so they act as endogenous vasodilators (think sepsis)
-Inc CO, dec SVR, dec ABP
-Decreased blood viscosity
-Can lead to cardiomyopathy/CHF
How is Anemia caused by Liver Dysfunction?
Anemia is common in advanced hepatic disease.
-Hemolysis, folate deficiency, hemorrhage, or bone marrow suppression can occur.
How does Congestive Splenomegaly occur?
Obstruction of blood flow causes portal hypertension. Blood backs up to the spleen, causing congestive splenomegaly.
-Leads to platelet sequestration and thrombocytopenia
-Also causes Leukopenia
How is clotting affected with Liver Disease?
-Clotting factors are deficient
-Decreased clearance of fibrinolytic factors (increased fibrinolysis)
What are the Respiratory effects of Liver Dysfunction?
Restrictive Ventilatory Effects:
-Ascites prevents diaphragmatic descent, decreasing FRC
-Laying patient supine decreases FRC naturally
-Worse in COPD patients with alcoholism.
What is Hepatopulmonary Syndrome?
A triad of:
-Liver Disease
-Arterial Deoxygenation
-Widespread Pulmonary Vasodilation
Uncommon. Affects the lungs of people with advanced liver disease.
-Blood vessels in lungs dilate and increase in number, making it challenging for RBCs to absorb O2.
-V/Q mismatch. Lungs are unable to exchange, causing hypoxemia.
-Try to improve reversible pulmonary dysfunction if possible (thoracentesis or paracentesis)
-Be very careful with sedatives/opioids preop
What is Hepatic Hydrothorax?
Pleural effusion occurs due to fluid backing up.
What changes in fluid balance occur with Hepatic Disease?
-Relative intravascular hypovolemia due to paracenteses, diuretics, and AV shunting
-Increased hydrostatic pressure in hepatic venous system
-Decreased plasma oncotic pressure
-Leads to ASCITES and edema
What fluid and electrolyte disturbances are associated with Hepatic Disease?
Hypoalbuminemia
Sodium retention
Progressive decline in renal function
Decreased free water clearance
Dilutional hyponatremia
Hypokalemia
How does Liver Disease cause Renal Dysfunction?
Nothing is wrong with the kidneys themselves, but are experiencing renal hypoperfusion.
-Progressive decline in renal function.
-Can lead to Hepato-Renal Syndrome (HRS) and multi-system organ failure
-Supportive therapy
-Liver transplant
What is Hepatorenal Syndrome (HRS)?
Renal failure occurring with hepatic failure and portal hypertension.
-Impaired renal function without abnormality of the kidneys
-Due to decreased renal blood flow and decreased GFR
-95% mortality within weeks of onset
-Hepatic Transplant is only definitive treatment
Nagelhout:
-Need to increase RBF through renal vasodilation and vasoconstriction of splanchnic circulation
How does Liver dysfunction affect the CNS?
-Inability to clear neurotoxins from the GI tract leads to accumulation of nitrogenous wastes (Ammonia)
-Ammonia erodes the BBB, leads to brain edema.
Precipitating factors:
-GI bleed
-Electrolyte abnormalities
-Acid-Base Disorders
-Sepsis
What are the S/Sx of Hepatic Encephalopathy?
S/Sx:
-Asterixis (flapping of wrists)
-Hyperreflexia
-Mental Status Changes
-Eventually, Coma
What is the treatment for Hepatic Encephalopathy?
-Lactulose: alters pH of colon
-Neomycin: decreases colonic bacteria, preventing urea from being converted into ammonia. Decreases amount of ammonia being produced.
-Dietary protein restriction to decrease ammonia
What is Acute Hepatitis?
A mild inflammatory response to fulminant hepatic failure.
-1-2 week prodromal period
-S/Sx: Fever, malaise, N/V, jaundice
-Resolves in 2-12 weeks
What are the causes of Acute Hepatitis?
Viral:
-A, B, C, D & E
-Epstein-Barr virus
-Cytomegalovirus
Hepatotoxic substances
Adverse drug reactions
Which are the different routes of transmission of Hepatitis?
A & E: oral-fecal
B & C: body fluids and disrupted cutaneous barriers
Asymptomatic carriers: B & C
Chronic hepatitis:
B: 3-10%
C: 10-50%
How is the Epstein-Barr Virus spread?
-Oral-oral contact
-Usually mild hepatitis
-Severe & fatal: RARE
What is Cytomegalovirus?
-Herpes virus
-Mimics viral hepatitis
-Usually mild
What is Drug-Induced Acute Hepatitis?
Drug-related injury to the liver results from an idiosyncratic reaction to a substance or an overdose resulting in toxicity.
-Resembles viral hepatitis
-Alcohol hepatitis is most common form of drug-induced hepatitis, results in fatty infiltration of the liver (causing hepatomegaly)
What is Chronic Persistent Hepatitis?
-Limited to portal areas
-Relatively benign
-Hepatocyte function is preserved
-Progression to cirrhosis is rare
What is Chronic Lobular Hepatitis?
-Recurrent exacerbations of acute inflammation
-Progression to cirrhosis is rare
What is Chronic Active Hepatitis?
Progressive:
-Cellular destruction
-Cirrhosis
-Liver failure
Causes:
-Hep B or C
-Systemic Lupus Erythematosus
-Exposure to certain drugs (Methyldopa, Isoniazid, Nitrofurantoin)
What is Cirrhosis?
Hepatocyte necrosis.
-Liver parenchyma (cells) are replaced by fibrous, nodular tissue that causes an interruption of portal venous blood flow.
-Liver function is now affected, get increased pressure in the portal system.
Nagelhout:
-Cirrhosis is defined as the histologic development of regenerative nodules surrounded by fibrous bands in response to chronic liver injury, which leads to portal hypertension and end-stage liver disease.
