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.
What are the causes of Cirrhosis?
-Chronic hepatitis
-Chronic alcoholism
-Biliary obstruction
-Right sided heart failure
What are the rare causes of Cirrhosis?
-NASH
-Alpha 1 antitrypsin deficiency
-Hemochromatosis
-Wilson’s Disease
-Budd-Chiari malformation
What is Nonalcoholic Steatohepatitis (NASH)?
AKA Non-alcoholic fatty liver disease
-Broad spectrum of liver disorders r/t steatosis. Not due to alcohol use!!!!!
-Ranges from simple benign, to hepatitis.
-Inflammation of hepatocyte injury and may progress to cirrhosis and hepatocellular carcinoma.
-Associated with obesity, hyperlipidemia, and diabetes
What is Alpha 1 Antitrypsin Deficiency?
Alpha 1 antitrypsin is produced in the liver to coat and protect the lungs (prevents breakdown of elastin).
-Neutrophils break down elastin by producing elastase.
-When we have an infection, the immune system sends WBCs (neutrophils) to attack bacteria, but they secrete elastase.
-Deficiency in A1A leads to the breakdown of elastin in lungs, leading to diffuse, damaged lung and eventual COPD.
-Diffuse damage to the lungs even if they’ve never smoked
-A1A accumulates in the liver, leading to hepatomegaly and eventual liver transplant being necessary
What is Hemochromatosis?
An autosomal recessive disorder
-Iron deposits throughout the body
-Pancreas: DM
-Heart: CHF
-Hepatocellular carcinoma occurs in 15-20% of patients
What is Wilson’s Disease?
An autosomal recessive disorder
-Defect in the gene needed for copper binding
-Leads to decreased serum ceruloplasmin (a protein that carries copper from the liver to the bloodstream and takes it where it is needed)
-Leads to copper accumulation throughout the body
-Will see distinct Kayser-Fleischer ring (copper ring) around the iris
-Neurologic and hepatic dysfunction due to copper being deposited around the body
What is a Budd-Chiari Malformation?
The formation of hepatic vein thrombosis.
What is Portal Hypertension?
Portal vein pressure > 20 mmHg
(normally 7-10 mmHg)
Backflow of blood leading to engorgement of key organs that feed the portal vein.
What are Gastroesophageal Varices?
-Dilated mucosal veins due to reversal of portal venous (Splanchnic) blood
-May or may not bleed
-If they rupture, very problematic
-Hemodynamically significant
-Distal esophagus or proximal stomach
-The development of esophageal varices places the patient at risk for spontaneous, severe, upper GI hemorrhage.
What is the treatment for Gastroesophageal varices?
-Banding (stops blood from leaking)
-Ligation
-Sclerotherapy (injecting a solution right into vein, causing it to scar and blood to reroute)
-TIPS procedure
-Octreotide
What is the purpose of using Octreotide with esophageal varices?
Reduce portal and variceal pressures, as well as the splanchnic and systemic collateral blood flow. Decreasing venous return to the portal circulation.
What is the cause and treatment of Ascites?
Causes:
-Portal HTN
-Hypoalbuminemia
-Na & H2O retention
Treatment:
-Diuresis
-LeVeen Shunt
-Paracentesis
-TIPS procedure
What are the S/Sx of Spontaneous Bacterial Peritonitis?
A complication of cirrhosis.
-Fever (hyperdynamic state)
-Leukocytosis
-Abd pain
-Decreased bowel sounds
-Mortality is 50% after first episode
What are the nutritional issues associated with Cirrhosis?
-Protein calorie malnutrition (low protein, no appetite, N/V is frequent)
-Megaloblastic anemia is common (folate is antagonized by alcohol)
Why does Cirrhosis lead to hyperdynamic circulation?
Massive vasodilation of the splanchnic and periphery.
-Decreased blood viscosity secondary to anemia
Why does arterial hypoxemia occur with Cirrhosis?
-PaO2 of 60-70 mmHg is normal in cirrhotic patients
-Blood vessels in lungs are dilating, difficult for RBCs to absorb the O2
-Diaphragm movement is impaired from ascites
-Lungs are unable to deliver adequate amounts of O2 to the body
-R to L pulmonary shunting occurs due to Portal HTN, smoking, COPD
-Possibly pneumonia
Why does hypoglycemia occur with cirrhosis?
Malnutrition leads to decreased glycogen stores.
-Impaired gluconeogenesis: Liver is unable to convert Lactic acid into glucose
Why is the immune system impaired with Cirrhosis?
Alcohol impairs immune system.
Pt at risk for:
-Viral infection
-Bacterial infection
-Cancer
-TB
