Wound dressing

• Wound


  A break or disruption in the normal integrity of the skin and tissues
• Wounds are varied in size, depth, and severity
• Causes of Wounds

  • Mechanical forces: surgical incision
  • Physical injury: e.g. burn
• Types of Wounds

  • Open: Incision, Laceration, Abrasion, Puncture
  • Closed: Contusion, Haematoma, Sprain
• Acute Wounds


  Usually heal within days to weeks, wound edges are well approximated, move through the normal healing process
• Chronic Wounds


  Do not progress through the normal sequence of repair, remain in the inflammatory phase of healing, normal healing time is delayed, high risk of infection
• Wound Depth

  • Partial-thickness (superficial) - confined to skin, dermis and epidermis
  • Full-thickness - involve the entire dermis, epidermis, subcutaneous tissues, and possibly muscle and bone
• Wound Classification

  • Class 1: Clean wound
  • Class 2: Clean-contaminated wound
  • Class 3: Contaminated wound
  • Class 4: Dirty-infected wound
• Wound Healing


  A process of tissue response to injury, normally occurs without assistance but interventions can support the process
• Wound Closure

  • Healing by Primary Intention
  • Healing by Secondary Intention
  • Healing by Tertiary Intention
• Healing by Primary Intention

  All layers are closed, incision heals in minimum time with no separation of wound edges and minimal scar formation
• Healing by Secondary Intention

  Wound is extensive with tissue loss, require more tissue replacement, wound edges not well approximated, longer repair time, greater scarring, greater susceptibility to infection
• Healing by Tertiary Intention

  Wounds left open for 3-5 days to allow edema/infection to resolve or exudates to drain, then closed with sutures/staples/adhesives, more scarring than primary but less than secondary
• Phases of Wound Healing

  • Hemostasis
  • Inflammation
  • Proliferation
  • Remodeling
• Hemostasis


  Occurs immediately after injury, utilizes clotting factors to prevent further blood loss and provide structural foundation for granulation tissue, lasts 3-6 days
• Inflammation Phase


  Follows hemostasis, lasts 4-6 days, characterized by redness, swelling, heat, and pain, white cells move to wound to ingest bacteria and debris, macrophages enter to ingest bacteria and release growth factors
• Proliferative Phase


  Also called fibroblastic, regenerative, or connective tissue phase, lasts several weeks, new tissue is built to fill wound space, connective tissue cells synthesize collagen and produce growth factors, epithelial cells form across wound
• Remodeling Phase


  Final stage, begins 3 weeks after injury, continues for months to years, collagen deposited in wound is remodeled and contracted, making healed wound stronger but less elastic than uninjured tissue
• Factors Affecting Wound Healing


  • Systemic: Age, Health status, Nutritional status, Lifestyle, Medications
  • Local: Pressure, Desiccation, Maceration, Repeated trauma, Edema, Infection, Excessive bleeding, Necrosis
• Obesity is associated with increased risk of ischemia and inadequate tissue oxygenation, which may lead to slowed wound healing or necrosis
• Malnutrition, specifically inadequate protein intake, can lead to decreased blood vessel formation, collagen production, and fibroblasts proliferation, which ultimately slows the wound healing process
• Smoking affects blood flow by causing vasoconstriction and decreases the body's immune response, leading to increased likelihood of wound infection
• NSAIDs are known to slow wound healing through the halting of angiogenesis, and increase scar formation if used during the proliferative phase
• Immunosuppressants like steroids can slow down the rate of cell production, delaying wound healing
• Radiation therapy and chemotherapy can also slow down the rate of cell production, delaying wound healing
• Wound Complications

  • Haemorrhage
  • Infection
  • Dehiscence
  • Evisceration
  • Fistula formation
• Haemorrhage

  Refers to blood loss (massive bleeding) inside the body, caused by a dislodged clot, slipped stitches, or erosion of a blood vessel
• Wound Infection

  Presence of bacteria or other organisms that multiply and overcome host resistance, indicated by redness, oedema, localised heat, pain, change in exudate, and malodor
• Dehiscence


  A medical emergency where the wound edges separate
• Necrosis


  Delays wound healing
• Wound complications

  • Haemorrhage
  • Infection
  • Dehiscence
  • Evisceration
  • Fistula formation
• Pressure injuries are defined as the breakdown of skin integrity and underlying tissue usually occurs over bony prominence or related to the use of a device
• Haemorrhage


  Blood loss (massive bleeding) inside the body
• Pressure injuries


  Previously known as pressure ulcers, pressure sores, or bed sores
• Interventions for haemorrhage

  1. Frequent checking of the dressing

  2. Apply additional pressure dressing

  3. Fluid replacement therapy

  4. Surgical repair of the bleeding site
• The most common site for pressure injuries is the sacrum
• Wound infection


  Presence of bacteria or other organisms, which multiply and lead to the overcoming of host resistance
• Local indicators of wound infection

  • Redness (erythema or cellulitis)
  • Oedema
  • Localised heat
  • Localised pain
  • Exudate (change to purulent fluid or increase in amount)
  • Malodor
• Mechanisms of pressure injury development

  1. External pressure - compress blood vessels

  2. Friction and Shear - tear and injure blood vessels and abrade the top layer of skin
• Dehiscence


  Partial or total rupturing of a sutured wound