New Material: Lectures 9-13
Lecture 9: Infection Control, Skin Integrity and Wound Care
Infection Control (Chapter 24)
Components of a potential infection:
• Infectious agent: bacteria, viruses, fungi
• Reservoir: natural habitat of the organism
• Portal of exit: point of escape for the organism
• Means of transmission: direct contact, indirect Five Moments for Hand Hygiene (WHO)
contact, airborne route 1. Before touching a patient
• Portal of entry: point at which organisms enter a 2. Before a clean or aseptic procedure
new host 3. After a body fluid exposure risk
• Susceptible host: must overcome resistance 4. After touching a patient
mounted by host’s defenses 5. After touching a patient surroundings
Hospital-Acquired Infections (HAIs) Categories: Multidrug-Resistant Organisms: use PPE and supplies
• CAUTI: Catheter-associated urinary tract infection • MRSA: methicillin-resistant Staphylococcus aureus
• SSI: Surgical site infection • VRSA: vancomycin-resistant Staphylococcus aureus
• CLABSI: Central-line associated bloodstream • CRE: carbapenem-resistant Enterobacteriaceae
infection • C-Diff: C. difficile (clostridium difficile)
• VAP: Ventilator-associated pneumonia
Precaution Categories:
➢ Standard Precautions: used in the care of all hospitalized patients; applies to all body fluids (except sweat), nonintact skin,
& mucous membranes
• New additions: respiratory hygiene/cough etiquette, safe injection practices, and wearing a mask during high-risk
prolonged procedures (spinal canal punctures)
➢ Transmission-Based Precautions: aka isolation precautions; prevent the spread of infection and are used in addition to
standard precautions
• Contact precautions: for pathogens transmitted via direct contact → use of gloves and gown
• Droplet precautions: for pathogens transmitted via respiratory droplets (i.e., coughing sneezing) → use of mask
(patient may also wear a mask to reduce droplets at the source)
• Airborne precautions: for pathogens transmitted via airborne routes (e.g., TB, measles, etc.) → use an N95 or
higher-level respirator
Preventing Occupational Exposures:
➢ OSHA: (Occupational Safety and Health Administration); the bloodborne pathogens standards to prevent occupational
exposure
• Prevent needlestick injuries: avoid recapping, use safety devices, and discard needles in the sharps bin
• Report accidental exposure: immediate management of the exposure site – wash the area with warm water and
soap, flush mucous membrane, or irrigate eyes, followed by reporting the incident and following the protocols
➢ Aseptic Technique: includes all activities to prevent or break the chain of infection
• Medical asepsis: clean technique
• Surgical asepsis: aka sterile technique; OR and L&D areas, certain diagnostic testing areas, and patient bedside for
certain procedures (urinary catheter insertion, sterile dressing changes, or preparing and injecting medicine)
Skin Integrity and Wound Care (Chapter 32)
Skin Layers:
➢ Epidermis: outermost layer of the skin; thickness varies from 0.1 – 1mm (i.e., eyelids vs palms/soles, respectively); avg pH
of 5.5; contains and regulates melanin production; composed of several layers
• Stratum corneum: is the thin, outermost layer that is flattened with dead keratinized cells
• Basal layer: divides, proliferates, and migrates towards the epidermal surface
• Dermis: thick, deeper layer of the skin; composed of collagen, elastin, and fibers with an extra-cellular matrix which
contributes to the skin strength & pliability
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,Types of Wounds:
• Incision: cutting or sharp instrument; wound edges aligned and in close approximation
• Contusion: blunt instrument, skin remains intact, with injury to underlying soft tissue; possible bruising and/or hematoma
• Abrasion: friction; rubbing or scraping epidermal layers of skin; top layer of skin abraded
• Laceration: tearing of skin and tissue with blunt or irregular instrument; tissue not aligned, often w loose flaps of skin/tissue
• Puncture: blunt or sharp instrument puncturing the skin; intentional (such as venipuncture) or accidental
• Pressure Ulcers: compromised circulation secondary to pressure or pressure combined with friction
Classifying Wounds:
➢ Intentional vs unintentional: describes how the wound was acquired
• Intentional wound: the result of planned invasive therapy or treatment; wound edges are clean,
bleeding is controlled, and risk of infection is decreased (i.e., from surgery, IV therapy, lumbar puncture)
• Unintentional wound: the result of unexpected trauma; wound edges are usually jagged, bleeding is usually
uncontrolled, and contamination/infection is likely (i.e., stabbing, GSW, burns, etc.)
➢ Open vs closed: describes the skin integrity related to the wound
• Open wound: the skin surface is broken (i.e., incisions or abrasions); bleeding, tissue damage, increased risk for
infection, and delayed healing; may occur with both intentional or unintentional trauma
• Closed wound: the result of <blunt-force trauma= or strain; the skin is not broken, but internal tissues are
damaged (i.e., ecchymosis and hematomas)
➢ Acute vs chronic: describes whether or not the wound follows normal healing progression
• Acute wound: usually heals within days-weeks; wound edges well-approximated & there’s low risk for infection;
wound progresses unimpeded through the phases of healing
• Chronic wound: delayed healing time (>30days); wound edges are not approximated & risk for infection is
increased; wound progression through phases of healing is impeded (usually in the inflammatory phase).
➢ Thickness: describes pressure injuries
• Partial thickness: all or a portion of the dermis is intact
• Full thickness: the entire dermis and sweat glands and hair follicles are severed, which can expose bone, tendon,
or muscle
• Unstageable: a full-thickness loss where the true depth cannot be determined; may also involve deep tissue injury
Phases of Wound Healing:
1. Hemostasis: occurs immediately after initial injury
• Constriction & Clotting: blood vessels constrict and blood clotting begins by platelet activation and aggregation
• Dilation: after a short time, blood vessels dilate (capillary permeability↑), allowing exudate formation
• Exudate accumulation: causes pain & swelling
• Increased perfusion: causes heat & redness
2. Inflammatory phase: lasts 4-6 days (textbook says 2-3days)
• Acute inflammatory response: WBCs move into wound causing localized pain, heat, redness and swelling
• Systemic body response: generalized mild temp elevation, leukocytosis and malaise
3. Proliferation phase: aka fibroblastic, regenerative or connective tissue phase; lasts for several weeks. New tissue is built to
fill wound space through action of fibroblasts. New tissue called granulation tissue. Forms foundation for scar tissue.
Granulation tissue is red, highly vascular.
4. Maturation phase: 3 weeks after injury. Can last for months or years. Collagen that has been deposited haphazardly is
remodeled making wound stronger. Scar tissue- strong but less elastic than uninjured tissue.
Types of Wound Healing:
• Primary intention: edges closely approximated and can be closed by stitches, staples, skin glue, etc. (i.e., surgical incision)
• Secondary intention: edges that are not closely approximated and cannot be closed, requiring longer healing times (i.e.,
burns or major trauma)
• Tertiary intention: aka delayed primary closure; are wounds intentionally left open for several days to allow exudate to
drain or infection to resolve before closing (i.e., abdominal wound left open to allow drainage of exudate before closure)
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, Local Factors Affecting Wound Healing:
• Pressure: disrupts blood flow • Infection: increases stress on the body
• Desiccation: dehydration • Excessive bleeding: clotting and O2 issues
• Maceration: overhydration • Necrosis: death of tissue (slough or eschar)
• Trauma: repeated trauma • Biofilm: thick grouping of microorganisms
• Edema: interferes with blood flow
Systemic Factors Affecting Wound Healing:
• Age: children and healthy adults heal more rapidly
• Circulation and oxygenation: adequate blood flow is essential
• Nutritional status: healing requires adequate nutrition
• Wound etiology: specific condition of the wound affects healing
• Medications & Health status: corticosteroid drugs and postoperative, radiation therapy delay healing
• Immunosuppression: as a result of disease (AIDs, Lupus), medication (chemo), or age, can delay healing
• Adherence to treatment plan: nonadherence will delay healing
Wound Complications:
• Infection: occurs when immune system fails to control microorganism growth (signs of acute infection include redness,
increased temperature, swelling, pain, increased WBC counts, & increased drainage)
• Hemorrhage: may be caused by slipped suture, dislodged clot at wound site, infection or erosion of a blood vessel by a
foreign body (i.e., drain)
• Dehiscence: partial or total separation of wound layers as a result of excessive stress on wounds that are not healed (A in
diagram)
o Evisceration: the most serious complication of dehiscence (primarily with abdominal incisions); the wound
completely separates, with internal organ protrusion through the incisional area (B in diagram)
• Fistula Formation: abnormal opening between one organ and another or between one organ and the outside of the body
(e.g., rectovaginal fistula)
Wound Assessment: inspection for sight and smell
• Appearance, drainage, and pain
• Sutures, drains or tube, manifestation of complications
• Documentation of findings
RYB-Color Classification of Wounds:
• Red: proliferative stage of healing; color of normal granulation → must be protected (moist dressings/dressing changes)
• Yellow: characterized by oozing slough/exudate → needs to be cleansed
• Black: covered with thick eschar → requires debridement
• Mixed wound: contains components of RY&B wounds
Types of Drainage: (clockwise, starting at top right)
• Purulent: is thick, foul smelling, dark yellow or green; consists of WBCs, debris, & dead and live bacteria
• Sanguineous: looks like blood (varying degrees of red); consists of large numbers of RBCs
o Bright-red: indicatives of fresh bleeding
o Dark-red: indicates older bleeding
• Serosanguineous: is light pink to blood tinged; a mixture of serum and RBCs
• Serous: is clear and watery; consists of fluid from the serous portion of the blood and serous membranes
Pressure Injuries: localized injury to the skin and other underlying tissue, usually over a bony prominence
➢ Causes: they occur as a result of pressure or pressure in combination with shear and/or friction:
• External pressure: compresses blood vessels (ischemia)
o Friction and shearing forces: tear and injure blood vessels and abrade the top of layer of skin
▪ Friction: skin rubs against other surfaces (or itself) to superficial damage resembling an abrasion
▪ Shear: one layer of tissue slides over another layer, causing the skin to separate from underlying
tissue
o Risk factors: Immobility, nutrition & hydration, moisture, mental status, and age
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