MED SURG

• Inflammation


  A physiological process that occurs in response to injury or infection
• Inflammation


  • The response is a defense mechanism (non-specific immune response) to protect the body from infection and injury
  • The purpose is to localize and eliminate the injurious agent and to remove damaged tissue components so that the body can begin to heal
  • Characterized by cardinal symptoms of PRISH i.e. pain, redness, immobility (possibly the loss of function), swelling, heat

  
• Acute inflammation


  Sudden onset, short term, usually lasts 1-2 weeks, acute symptoms
• Chronic inflammation


  Insidious (harm) onset, can last from weeks to months, persistent low grade fever, vague aches & pains, difficult to treat
• Causes of inflammation


  • Exogenous causes: Physical injuries or wounds
  • Excessive heat or cold
  • Allergic or hypersensitivity reactions – allergens, toxic compounds, irritants, foreign bodies
  • Ingestion of poisons
  • Endogenous causes: Products of tissue decay (dead, damaged, malfunctioned, stressed)
  • Endogenous chemical agents
  • Infections caused by pathogens e.g. bacteria, virus
  • Diseases or conditions
• Physical injuries or wounds

  • Burns: Heat or fire
  • Moist heat
  • Acid burns
• Excessive heat or cold

  • Sunburn: Caused by over exposure to the sun
  • Frostbite: Excessive exposure to extreme cold
• Allergic or hypersensitivity reactions

  • Acne Vulgaris: Caused by makeup, cleaning gel
  • Eczema (atopic dermatitis): Allergies to pollen, animals, dust, mites
• Ingestion of poisons


  Any substances that is harmful to the body when ingested whether intentionally or unintentionally
• Endogenous causes


  • Infections caused by pathogens: Bacteria, Mycobacterium tuberculosis causes Tuberculosis, Virus, Human Immunodeficiency Virus causes AIDS, Herpes Simplex Virus causes Herpes simplex
  • Diseases or conditions: Asthma, Gastritis
• Pathophysiology of inflammation


  1. Disruption of tissue integrity

  2. Injury

  3. Ischemic damage

  4. Immune reaction

  5. Inflammatory response

  6. Vascular changes

  7. Cellular changes
• Vascular changes


  • Vasodilation
  • Increase permeability
  • Increase blood flow
  • Local tissue congestion
• Local effects


  • Erythema
  • Warmth
  • Oedema
  • Pain
  • Impaired functioning
• Cellular changes


  • Phagocytosis
  • Increase leukocytes
  • Release of chemical mediators (mast cells and macrophages)
• Systemic effects


  • Fever
  • Malaise
  • Anorexia
  • Sepsis
• Stages of inflammation


  1. Vascular response

  2. Cellular response

  3. Tissue repair or healing
• Vascular response


  1. Short term vasoconstriction

  2. Vasodilatation

  3. Increase blood flow and vasocongestion

  4. Increased hydrostatic pressure and increased vascular permeability

  5. Fluid move out from blood capillaries into interstitial spaces (exudates) causing localized oedema
• Cellular response


  1. Leucocytes move out of blood vessels and migrate to the site of injury

  2. Leucocytes engulf bacteria, damaged cells exudates and cellular debris (phagocytosis) and prepare the site for healing
• Tissue repair or healing

  1. Proliferative phase: New blood vessels supply oxygen and nutrients to sustain growth of new cells and collagen

  2. Remodelling phase: Collagen synthesis and ongoing in order to strengthen the tissue

  3. Re-epithelialization: The process of laying down new skin or epithelial cells

  
• Granulation tissue


  New connective tissue and microscopic blood vessels that form on the surfaces of a wound during the healing process

  
• Clinical manifestations


  • Local manifestations: Redness or erythema, Warmth, Oedema, Pain, Pus, Loss of function
  • Systemic manifestations: Fever, Headache, Anorexia, Malaise, Tachycardia, Leucocytosis (WBC), Enlarged lymph nodes
• Classification of inflammation


  • Onset & Time frame: Acute, Chronic
  • Types of exudate: Serous exudate, Purulent exudate
  • Structure involved: Words which end with "...itis"
  • Based on causative organism: Bacteria inflammation, Fungi inflammation
• Serous exudate


  Plasma derived from blood, Thin clear watery secretions
• Purulent exudate


  Or suppurative exudate, Referred as pus, Refer to yellow, grey or green drainage
• Bacteria inflammation


  • Reproduce quickly in body, Produce toxins, which can damage tissue and cause sickness, Include: Streptococcus, Staphylococci, E.coli
• Fungi inflammation


  • Often start in the lungs or skin, Prone to infection if weakened immune system, Produce through tiny spores in the air
• Effects of inflammation


  • Resolution: Complete restoration of the inflamed tissue back to a normal status
  • Fibrosis: Fibrous scarring occurs called Keloids
  • Suppuration: Abscess formation, Contain pus
  • Necrosis: Very toxic bacteria destroy large areas of tissue & blood vessels, This impedes (block) blood flow - death of tissues (Gangrene)
  • Chronic inflammation: Marked by inflammation lasting many days, months or even years, May lead to the formation of a chronic wound

  
• Keloids


  An overgrowth of collagenous scar tissue at the site of a skin injury, particularly a wound or a surgical incision. The new tissue is elevated, rounded, and firm

  
• Classification of infection


  • Location: Local infection, Systemic infection, Bacteremia, Septicemia
  • Speed: Acute infection, Chronic infection
  • Stages: Primary, Secondary
• Local infection


  An infection that is limited to a specific part of the body where the microorganism remain
• Systemic infection


  The microorganisms spread and damage different parts of the body
• Bacteremia


  When a culture of a person's blood reveals microorganisms
• Septicemia


  When bacteremia results in systemic infection
• Acute infection


  Generally appear suddenly or last a short time
• Chronic infection


  May occur slowly, over a very long period, and may last months or years
• Primary infection


  The initial infection of a host by a pathogen that has completed a resting or dormant period
• Secondary infection


  A secondary infection is one that occurs when a different infection, known as a primary infection, has made a person more susceptible to disease
• Localized infection


  Infection that remains in one part of the body
• Systemic infection


  Microorganisms spread and damage different parts of the body
• Primary infection examples


  • Common cold, HIV