Lecture Notes: Pathophysiology - Inflammation and Tissue Repair

Learning Objectives

• Differentiate among the three lines of defense.
• Outline the process of acute inflammation and the role of chemical mediators.
• Describe healing and repair after tissue injury.
• Differentiate between acute and chronic inflammation states.
• Understand treatment methods for acute and chronic inflammation.
• Identify cardinal signs or clinical manifestations of inflammation.
• Apply concepts to clinical models.

Lines of Defense

First Line: Skin and Mucous Membranes

• Skin: Prevents harmful substances from entering the body.
• Mucous membranes: Protect through eyes (tears), blinking reflex, lashes, and enzymes.

Second Line: Inflammatory Response

• Activated when the first line is breached.
• Vasodilation: Increased blood flow.
• Chemical Response: Phagocytosis to engulf pathogens.

Third Line: Immune Response

• Activation of immune cells.
• Adequate response leads to disease resolution; inadequate response leads to spread.

Inflammation Response

Vascular Response Goals

1. Vasodilation: Increased blood flow to injury site.
2. Permeability: Healing cells reach injury site.
3. Tissue Repair Preparation: Preparing site for repair.

Acute Inflammation Process

• Begins at tissue injury.
• Involves inflammatory mediators: histamines, leukotrienes, prostaglandins.
• Phagocytosis: Engulfment of harmful agents.
• Clot Formation: Involves prostaglandins.

Inflammatory Mediators

• Vasoactive Mediators: Histamines, leukotrienes, prostaglandins.
• Chemotactic Mediators: Chemokines, chemotaxis, adherence, migration, phagocytosis.

Cardinal Signs of Inflammation

• Local: Heat, incapacitation, pain, redness, edema.
• Systemic: Fever, increased leukocytes and plasma proteins.

Diagnostics for Inflammation

• White Blood Cell Count
• ESR (Erythrocyte Sedimentation Rate)
• C-Reactive Protein (CRP)
• Complement Activity
• Prothrombin Time
• Fibrinogen Level

Treatment of Inflammation

General Goals

• Reduce blood flow.
• Decrease pain.
• Block chemical mediators.
• Decrease swelling.

Non-Pharmacological Methods

• RICE Method: Rest, Ice, Compression, Elevation.
• Warmth, gradual movement, optimal fluid and nutrition intake.

Pharmacological Agents

• NSAIDs
• Glucocorticoid Steroids
• Aspirin

Healing and Tissue Repair

Phases of Healing

1. Inflammatory Phase: Sealing the wound.
2. Proliferative Phase: Cleaning debris, restoring structural integrity.
3. Remodeling Phase: Restoring functional integrity.

Complications of Healing

• Infection, ulcerations, dehiscence, keloids, adhesions.

Chronic Inflammation

• Persistent inflammation over weeks or longer.
• Involves macrophages and lymphocytes.
• Characterized by remissions and exacerbations.

Treatment of Chronic Inflammation

• Long-term anti-inflammatory medications.
• Antimicrobial therapies.
• Heat and cold therapy, immobilization, dietary changes, exercise.

Clinical Models of Inflammation

Sinusitis

• Acute: Sudden, allergies/viruses; fever, facial pain.
• Chronic: Lasts 12+ weeks; low-grade fever, nasal congestion.

Burns

• Pathophysiology: Excessive heat, radiation, chemicals.
• Types: Superficial, deep partial thickness, full thickness.
• Rule of Nines: Classification.

Rheumatoid Arthritis

• Chronic inflammation of synovial membranes.
• Joint pain, stiffness, decreased mobility.

Gastritis

• Acute: Irritating substances; indigestion, pain.
• Chronic: H. pylori infection; indigestion, weight loss.

Pancreatitis

• Acute: Alcohol use/gallstones; abdominal pain.
• Chronic: Alcohol use/bile duct obstruction; diarrhea, steatorrhea.

Inflammatory Bowel Diseases

• Crohn’s Disease: Small intestine, non-continuous ulcerations.
• Ulcerative Colitis: Colon/rectum, continuous ulcerations.

Conclusion

• Review book and guided learning questions.
• Complete system disorder/disease cards.
• Reach out for clarifications.