Hepatic Disorders NURS 321

Anatomy of the Hepatic and Biliary System

• Key Structures:
    - Liver: The central organ of the hepatic system, located below the diaphragm.
    - Gallbladder: Connected via the cystic duct; stores and concentrates bile.
    - Ductal System:
      - Cystic duct: Leads from the gallbladder.
      - Hepatic duct: Leads from the liver.
      - Common bile duct: Formed by the union of the cystic and hepatic ducts.
      - Hepatopancreatic ampulla: The junction where the common bile duct and pancreatic duct enter the duodenum.
      - Pancreas: Consists of the head (near the duodenum), the pancreatic duct, and the tail (near the spleen).
      - Spleen: Located in the left upper quadrant, adjacent to the tail of the pancreas.
      - Duodenum: The first part of the small intestine where bile and pancreatic enzymes are secreted.

Functional Roles of the Liver

• Primary Functions:
    - Metabolic: Processing of carbohydrates, proteins, and fats.
    - Secretory: Production and secretion of bile for fat digestion.
    - Storage: Storing glucose (as glycogen), vitamins, and minerals.
    - Vascular: Serving as a blood reservoir and filtering blood through the portal system.

• Core Nursing Concepts:
    - Elimination: The liver's role in detoxifying substances and excreting bilirubin.
    - Nutrition: The liver's role in nutrient metabolism and storage.

Hepatitis: Etiology and Classifications

• Definition: Inflammation of the liver.

• Standard Etiology:
    - Viruses: The most common cause of inflammation.
    - Drugs and Alcohol: Especially hepatotoxic substances like Acetaminophen.
    - Chemicals: Exposure to industrial or environmental toxins.
    - Autoimmune Diseases: The body's immune system attacking liver cells.

Viral Hepatitis: Pathophysiology and Staging

• Viral Agents:
    - Six primary viruses: $A$, $B$, $C$, $D$, $E$, and $G$.
    - Most common types: $A$, $B$, and $C$.
    - Other contributing viruses: Cytomegalovirus ($CMV$), Epstein-Barr virus ($EBV$), Herpes virus, Coxsackievirus, and Rubella virus.

• Pathophysiology Phases:
    - Acute Phase:
      - Duration: $6$ months or less.
      - Mechanism: Lysis of hepatocytes caused by cytotoxic cytokines and natural killer cells.
      - Inflammation: Widespread inflammation that may interrupt bile and blood flow.
      - Necrosis: Tissue necrosis occurs during the peak of infection.
      - Regeneration: Liver cells typically regenerate after the infection resolves, restoring normal function.

  - Chronic Phase:
    - Duration: Greater than (>) $6$ months; can be lifelong.
    - Mechanism: Persistent inflammation causes progressive fibrosis and ongoing tissue necrosis.
    - Outcomes: Over time, this leads to compromised liver function, Cirrhosis, or Liver Cancer.

Comparative Analysis of Hepatitis A, B, and C

• Hepatitis A Virus (HAV):
    - Type: Acute only (never chronic).
    - Transmission: Fecal-Oral Route.
    - Sources: Poor personal hygiene, poor sanitation, contaminated food, water, milk, or shellfish.
    - Incubation: $15$ to $50$ days.
    - At-Risk Populations: Daycare workers/attendees, institutionalized individuals, Men who have Sex with Men ($MSM$).
    - Prevention: Hepatitis A Vaccine and Immune Globulin ($IG$).
    - Diagnostic Test: Anti-$HAV$ $IgM$ (indicated for acute infection).

• Hepatitis B Virus (HBV):
    - Type: Acute or Chronic.
    - Transmission: Percutaneous, Perinatal, or mucosal exposure to blood/bodily fluids; sexual contact.
    - Sources: Contaminated needles, blood products, tattoos, body piercings, or bites.
    - Incubation: $45$ to $180$ days.
    - At-Risk Populations: Healthcare workers, hemodialysis patients, transplant recipients, unprotected sex ($MSM$), and injection drug users.
    - Prevention: Hepatitis B Vaccine and Hepatitis B Immune Globulin ($HBIG$).
    - Diagnostic Test: $HBsAg$ (Hepatitis surface antigen) or Anti-$HBc$ $IgM$.

• Hepatitis C Virus (HCV):
    - Type: Acute or Chronic.
    - Transmission: Percutaneous (needles), high-risk sexual activity, blood/blood products (prior to the $1990s$).
    - Incubation: $14$ to $180$ days.
    - At-Risk Populations: IV drug users, $HIV+$ $MSM$, individuals receiving blood products before precise screening ($1990s$).
    - Prevention: No vaccine available; rely on needle safety and safe sex.
    - Diagnostic Test: Anti-$HCV$ (tests for acute or chronic infection).

Clinical Manifestations of Acute Viral Hepatitis

• Incubation Phase:
    - The period after the virus is acquired; symptoms begin to emerge.

• Acute Phase (Highly Infectious):
    - Duration: $1$ to $6$ months.
    - Systemic Symptoms: Fatigue, low-grade fever, myalgias, arthralgias, and headaches.
    - GI Symptoms: Anorexia, weight loss, nausea, vomiting, and abdominal tenderness.
    - Physical Findings: Hepatomegaly, Splenomegaly, and Lymphadenopathy.
    - Icteric Symptoms: Jaundice (yellowing), dark urine (excess bilirubin), clay-colored stools (lack of bile), and pruritus (itching).

• Convalescent Phase:
    - Duration: Weeks to months (Average: $2$ to $4$ months).
    - Progression: Fever subsides and jaundice resolves.
    - Organ Recovery: Splenomegaly subsides; hepatomegaly persists but slowly subsides.
    - Persistence: Fatigue and malaise may continue for some time.

Diagnostic Evaluation of Hepatitis

• Primary Method: Hepatitis antigens and antibodies; viral load (viral level in blood).

• Liver Function Tests (LFTs):
    - Liver Transaminases: $AST$, $ALT$, $GGT$.
    - Enzymes: Alkaline phosphatase, $LDH$ (lactate dehydrogenase).

• Serums: Serum albumin (decreases in failure), Serum bilirubin (increases).

• Coagulation: $PTT$ (Prothrombin time) and $INR$.

• Tissue Analysis: Liver Biopsy (to assess the degree of fibrosis).

Collaborative Care for Viral Hepatitis

• Acute Management:
    - Rest: Essential for liver cell regeneration.
    - Location: Usually managed at home as an outpatient.
    - Nutrition: Goal is to maintain calorie intake to avoid weight loss. Small, frequent meals; high oral fluid intake; vitamin supplementation.
    - Abstinence: Avoid alcohol and Acetaminophen.

• Drug Therapy:
    - Supportive: Antiemetics for nausea; Diphenhydramine (Benadryl) for pruritus.
    - Chronic Hepatitis B: Interferon, Nucleoside & nucleotide analogs (antivirals) like lamivudine (Epivir $3TC$), adefovir dipivoxil (Hepsera), and Telbivudine (Tyzeka).
    - Chronic Hepatitis C: $ext{α-interferon}$, Direct-acting antivirals ($DAAs$), and Ribavirin.

• Prevention (Healthcare and Personal):
    - Vaccinations ($HAV$ & $HBV$).
    - Immune globulin ($IG$) for passive immunity post-exposure.
    - Universal (Standard) precautions (PPEs).
    - Disposable, one-time-use needles.

Drug and Chemical Induced Hepatitis

• Etiology: Hepatotoxic substances, most commonly Acetaminophen and Alcohol.

• Manifestations: Ranges from a slight elevation in $AST$ and $ALT$ to acute alcoholic hepatitis or advanced cirrhosis.

• Care: Supportive care; immediate removal of the offending substance; potential liver transplantation in severe cases.

Liver Cirrhosis: Pathophysiology and Etiology

• Definition: Extensive degeneration and destruction of the liver cells where liver lobules are replaced by nodes of scar tissue.

• Pathophysiology Process:
    - $1.$ Cell necrosis occurs.
    - $2.$ Native liver cells are replaced by scar (fibrotic) tissue.
    - $3.$ Regenerative efforts result in nodules (irregular sizes/shapes) rather than normal lobular structure.
    - $4.$ Abnormal blood flow through the fibrotic tissue leading to portal hypertension and decreased liver function.

• Etiology:
    - Alcohol abuse.
    - Chronic Hepatitis $B$ or $C$.
    - Biliary issues and $NASH$ (Nonalcoholic steatohepatitis).
    - Genetics and autoimmune diseases.
    - Cardiac problems (secondary to severe right-sided heart failure).

Clinical Manifestations of Cirrhosis

• Early Phase: Insidious; fatigue and mild GI symptoms; palpable liver.

• Late Phase Symptoms:
    - Neurologic: Hepatic encephalopathy, peripheral neuropathy, and Asterixis (flapping tremors).
    - Gastrointestinal: Anorexia, dyspepsia, nausea/vomiting, fetor hepaticus (musty breath), esophageal/gastric varices, and hematemesis.
    - Integumentary: Jaundice, spider angioma, palmar erythema, purpura, petechiae, and caput medusae.
    - Hematologic: Anemia, thrombocytopenia, leukopenia, and coagulation disorders.
    - Reproductive: Amenorrhea, testicular atrophy, gynecomastia, and impotence.
    - Metabolic: Potassium deficiency ($K$), hyponatremia ($Na$), and hypoalbuminemia.
    - Cardiovascular: Fluid retention, peripheral edema, and ascites.

Complications of Cirrhosis and Management

• Portal Hypertension: Increased venous pressure in portal circulation leading to splenomegaly, collateral veins, ascites, and varices.

• Esophageal and Gastric Varices:
    - Risk: Extremely high risk for bleeding/hemorrhage.
    - Prevention: Avoid $ASA$, alcohol, and irritating foods. Treat coughs promptly to prevent rupture.
    - Treatment: Inderal (propranolol); Balloon tamponade (Sengstaken-Blakemore tube); endoscopic procedures.

• Peripheral Edema and Ascites:
    - Treatment: Limit $Na^+$ intake; Diuretics; Paracentesis; Peritoneovenous shunt; $TIPS$ procedure.
    - Concerns: Bacterial peritonitis, dehydration, and hypokalemia.

• Hepatic Encephalopathy:
    - Cause: Liver cannot convert ammonia to urea; ammonia crosses the blood-brain barrier.
    - Sign: Change in mental status and Asterixis.
    - Care: Lactulose (promote ammonia excretion) and Neomycin; neuro checks; airway protection ($ABCs$).

Dietary Considerations for Cirrhosis

• General Diet: High calorie, high carbohydrate, low to moderate fat.

• Protein Conflict:
    - Low Protein: Needed if encephalopathy is present, but may worsen malnutrition.
    - High Protein: Needed for tissue repair/albumin, but worsens encephalopathy.
    - Standard Recommendation: Small frequent meals with restricted high-protein foods; consult a dietitian.

• Electrolytes: May need low Sodium ($Na^+$) and supplementation of $K$, $Mg$, and Phos.

Fulminant Hepatic Failure (Acute Liver Failure)

• Definition: Acute liver failure accompanied by hepatic encephalopathy; occurs suddenly.

• Primary Causes:
    - Combination of Alcohol and Acetaminophen overdose (most common).
    - Hepatotoxic meds: Isoniazid, halothane, sulfa drugs, and $NSAIDS$.
    - Hepatitis $B$ Virus ($2nd$ most common cause).

• Clinical Indicators: First sign is a change in mental status. Jaundice and coagulation abnormalities follow.

• Complications: Cerebral edema (herniation), renal failure, hypoglycemia, metabolic acidosis, and sepsis.

• Nursing Care:
    - Early ICU transfer.
    - Decrease $ICP$: Head of Bed ($HOB$) at $30$ degrees; decrease straining/coughing.
    - Liver transplant is the treatment of choice for stable patients.

Liver Cancer

• Types: Hepatocellular Carcinoma ($HCC$), Malignant Hepatoma, Cholangioma.

• Classification: Primary liver cancer is less common than metastatic disease from other sites (due to the liver's high blood flow filtration).

• Risk Factors: Hepatitis $B$ and $C$, alcoholic cirrhosis, obesity, diabetes, Hemochromatosis, and $NASH$.

• Diagnostics:
    - $AFP$ (alpha fetoprotein levels), Ultrasound, $CT$, $MRI$, and biopsy.

• Treatment:
    - Surgery: Excision or liver transplant if localized.
    - Radiofrequency Ablation: Using electrical energy to heat the tumor.
    - Chemoembolization: Direct injection of chemo into arteries feeding the tumor.
    - Chemotherapy: Limited efficacy; Sorafenib (Nexavar) is an option.

Liver Transplantation

• Candidate Criteria: Based on the $MELD$ (Model for End-Stage Liver Disease) Score.

• Donors:
    - Cadaveric donors.
    - Living donors (retrieval of the right lobe).

• Post-Transplant Focus: Focus on rejection prevention, infection control, and psychosocial support for the patient and family.