asepsis

• Microorganisms exist everywhere: in water, in soil, and on body surfaces such as the skin, intestinal tract, and other areas open to the outside (e.g., mouth, upper respiratory tract, vagina, and lower urinary tract)
• Communicable Disease


  An illness caused by an infectious agent or its toxins that occurs through the direct or indirect transmission of the infectious agent or its products from an infected individual or via an animal, vector or the inanimate environment to a susceptible animal or human host
• Virulence


  Severity or harmfulness of a disease
• Infection


  Implantation and successful replication of an organism in the tissue of the host resulting in signs and symptoms
• Infectious Agent


  Microorganism or Etiologic Agent
• Types of Microorganisms


  • Bacteria
  • Fungi
  • Parasites
  • Virus
• Pathogenicity


  Ability of an organism to produce a disease
• Pathogen


  Microorganism that causes disease
• A true pathogen is an infectious agent that causes disease in virtually any susceptible host.
• Asepsis


  Freedom from disease-causing microorganisms
• Medical Asepsis


  "Clean Technique" - practices intended to confine / reduce microorganism
• Surgical Asepsis


  "Sterile Technique" - practices that keep an area or object FREE of ALL microorganisms
• Sepsis


  The condition in which acute organ dysfunction occurs secondary to infection
• Bacteremia


  When a culture of the individual's blood reveals microorganisms
• Septicemia


  When bacteremia results in systemic infection
• Major Categories of Microorganisms

  • Bacteria
  • Virus
  • Fungi
  • Parasites
• Colonization


  The process by which strains of microorganisms become resident flora. In this state, the microorganisms may grow and multiply but do not cause disease
• Local infection


  Limited to the specific part of the body where the microorganisms remain
• Systemic infection


  The spread of infection to different parts of the body
• Acute infections


  Generally appear suddenly or last a short time
• Chronic infection


  May occur slowly, over a very long period, and may last months or years
• Nosocomial and Healthcare-Associated Infections

  Infections acquired in healthcare settings
• Healthcare-Associated Infections


  • CLABSI (Central IV Line-Associated Bloodstream Infection)
  • CAUTI (Catheter-Associated Urinary Tract Infection)
  • SSI (Surgical Site Infections)
  • VAP (Ventilator-Associated Pneumonia)
• CLABSI


  Causes: Improper tubing and site care technique, Inadequate hand hygiene
• CAUTI


  Causes: Improper catheterization technique, Contamination of closed drainage system, Inadequate hand hygiene
• SSI


  Causes: Improper dressing change, Inadequate hand hygiene
• VAP


  Causes: Improper suctioning, Inadequate hand hygiene
• Iatrogenic infections


  The direct result of diagnostic or therapeutic procedures. Ex: Bacteremia that results from an intravascular infusion line
• The hands of healthcare personnel are a common vehicle for the spread of microorganisms
• Factors contributing to nosocomial infections

  • ETIOLOGIC AGENT (any microbe capable of producing disease)
  • RESERVOIR (where organisms survives and multiplies)
  • PORTAL OF EXIT FROM RESERVOIR
  • METHOD OF TRANSMISSION
  • PORTAL OF ENTRY TO THE SUSCEPTIBLE HOST
  • SUSCEPTIBLE HOST (any individual who is at risk for infection)
• Body Defenses Against Infection

  • NON-SPECIFIC (protects the individual against ALL microorganisms)
  • SPECIFIC (specific defense against bacteria, viruses and other infectious agents)
• NON-SPECIFIC Body Defenses


  • Anatomic and Physiologic Barriers
  • Inflammation
• Anatomic and Physiologic Barriers

  • Intact skin and mucous membranes
  • Nasal passages (Cilia)
  • Lungs (Large Phagocytes)
  • Saliva "LAway" (Lactoferrin, Lysozyme, IgA)
  • Eyes (tears)
  • High acidity of stomach
  • Vagina (pH 3.5 to 4.5)
  • Urine flow (flushing and bacteriostatic)
• Stages of Inflammation


  • Vascular and Cellular Responses
  • Exudate Production
  • Reparative Phase
• Inflammatory Response


  Redness (Rubor), Heat (Calor), Swelling (Tumor), Pain (Dolor), Loss of Function
• Injurious Agents


  • Physical agents (mechanical objects causing trauma to tissues, excessive heat or cold, and radiation)
  • Chemical agents (external irritants like strong acids, alkalis, poisons, irritating gases, and internal irritants like hydrochloric acid in the stomach)
  • Microorganisms (bacteria, viruses, fungi, and parasites)
• Vascular and Cellular Response in Inflammation

  1. Blood vessels at injury site CONSTRICT

  2. Blood vessels DILATE (Histamine release)

  3. Increased blood supply = Hyperemia

  4. Increased Vascular Permeability

  5. Fluids, proteins, leukocytes LEAK into interstitial space = SWELLING

  6. Pressure on nerve endings = PAIN

  7. Loss of function
• Types of Exudates


  • Serous Exudates (contains chiefly of serum, e.g. blister from a burn)
  • Purulent Exudates (thicker than serous exudate, contains PUS)
• 3 stages of inflammation

  1. Vascular and cellular response

  2. Exudate production

  3. Reparative phase
• Vascular and cellular response

  • Leukocytosis
  • Blood vessels constrict
  • Blood vessels dilate (histamine release)
  • Increased blood supply (hyperemia)
  • Increased vascular permeability
  • Fluids, proteins, leukocytes leak into interstitial space (swelling)
  • Pressure on nerve endings (pain)
  • Loss of function