Wound Care Dressings

1. Characteristics of an ideal dressing

   1. keep wound moist
   2. prevent maceration
   3. protect from contamination
   4. contain wound fluid
   5. protect granulation tissue

2. Traditional dry dressings

   1. Wounds exposed to air are more inflamed, painful, itchy and have thicker crusts than moist wounds during the inflammatory stage of healing
      
      1. decreased collagen production
      2. dermis is more fibroplastic, fibrotic and scarred
   2. Epithelium migrates into wound bed: if must burrow between any eschar (crust or scab) healing is slower
   3. Wet to dry dressing significantly increase healing time
      
      1. greater pain
      2. greater cost
      3. increased frequency of dressing changes (bid, tid, qid)
   4. Nonocclusive: increased risk of contamination and infection

3. Moist wound healing

   1. Wound kept moist and protected from external environment
      
      1. no eschar develops (crust, scab)
      2. enhances autolytic debridement: promotes role of macrophages and leukocytes
      3. bacterial barriers: prevent wound contamination
      4. wound fluids kept at site: contain growth factors and enzymes that promote autolysis and healing
   2. Potential for infection
      
      1. Potential for increasing pathogen growth
         • use carefully with immunocompromised patients
         • occluded wounds show a shift from gram-positive to gram-negative organisms
      2. Signs of infection
         • I-induration
         • F-fever
         • E-erythema
         • E-edema
      3. Wound cultures need to be quantitative. Wound infection: > 105 colony forming units (CFU) of a specific pathogen per gram of tissue
   3. Accumulation of drainage
      
      1. Exudate: wound fluid containing dead cells, necrotic debris, liquefied eschar, growth factors, enzymes, etc.
      2. Drainage that is yellow in color and possesses an offensive odor is common with occlusive dressings (especially early when autolytic debridement is occurring)
      3. OSHA regulations state drainage must be contained: Maceration interferes with epithelialization
   4. General Principles
      
      1. Wounds generally get worse before they get better as ischemic tissue sloughs
      2. Odor often worsens
      3. Several methods need to be tried. Type of treatment changes during the course of healing.
      4. Primary goal of wound healing is to aid body's own healing mechanism
      5. Wounds can generally be treated based on appearance and drainage

4. Dressings used in moist wound healing

   1. Films: Moisture Vapor Permeable Dressing (MVP)

      1. Characteristics
         • porous enough to allow escape of moisture vapor but too small for bacteria and water to pass through
         • does not adhere to moist wound bed
      2. Uses: minimally exudative wound; excellent protection for fragile and/or newly healed tissue; promotes autolytic debridement for eschar covered wound without drainage.
      3. increase healing 20-40%
      4. Care:
         • examine frequently for patency. Loose edges can be resealed using a skin prep wipe
         • allow at least a 3 cm frame between the edge of the wound and the edge of the dressing
         • healthy autolytic debridement often creates a yellow, dark beige or brown drainage under the dressing
         • initially autolytic debridement will make the wound larger before healing begins
         • remove by lifting edges and wiping with alcohol wipe
         • change dressing if drainage two times size of wound. Maceration of surrounding tissue may occur if prolonged contact with drainage occurs.
      

   2. Foams (hydrophilic and hydrophobic)

      1. Characteristics
         • more permeable than film
         • absorbs more drainage
         • maintains body temperature in wound bed
      2. Uses: wounds with more drainage; full thickness wounds
      3. Care
         • not adhesive coated so require secondary dressing (net or film may be used)
         • secondary dressing may alter permeability
         • shiny side down (Lyofoam)
         • change dressing when see drainage on edge
         • needs to be two inches larger than wound
         • can use skin prep and apply foam before prep dries so held in place until can apply secondary dressing
           
           

   3. Hydrocolloid (hydrophilic colloidal particles)

      1. Characteristics
         • absorbs slowly
         • more occlusive: non permeable
         • ability to conform and seal
         • due to particle swelling, hydrocolloids develop a better seal the longer they are in place
         • do not adhere to wound
         • more effective bacterial barrier than films
      2. Uses: minimally draining wound
      3. Care
         • clean and dry skin surrounding wound; hydrocolloid will not stick to moist surfaces
         • conform and shape the dressing so contact is made with body contours
         • may be framed with tape
         • likely to see yellow-beige gelatinous mass covering wound because of dressing decomposition
         • may also have offensive odor when the dressing removed
         • do not need to completely remove gelatinous mass prior to applying new dressing
         • since no gas exchange, assess for presence of anaerobic bacteria
      

   4. Hydrogels

      1. Characteristics
         • contain 80-99% water
         • high specific heat so feel cool and soothing
         • slowly absorb minimal exudate
      2. Uses
         • treating wounds in patients with sensitive skin or in presence of hair
         • adds moisture to wounds
         • facilitates autolytic debridement
         • burns (Aquasorb and Vigilon)
         • packing necrotic wounds with gel satuated gauze
      3. Care
         • check label to verify sterile vs distilled water used
         • require secondary dressing to hold hydrogel in place
         • monitor for maceration in heavily draining wound

   5. Impregnated Dressings (Non adherent)

      1. May be saturated with vaseline, bismuth tribromophenate (3% Zeroform)
      2. Must be covered with secondary dressing
      3. If allowed to dry, may bond to wound
      4. Antibacterial and bacteriocidal impregnated dressings need to be used cautiously since may be cytotoxic
      5. Biobrane is a biosynthetic dressing that adheres to the wound surface, but not normal skin. Should not be removed until healing has occurred.
      

   6. Absorptive powders and pastes

      1. Usually starch copolymers or colloidal hydrophilic particles (cellulose, gelatin)
      2. Use: suer slurpers - used in heavily draining wounds: absorb up to 100x weight in fluid: may increase wound pH above physiological levels
      3. May require wrapping in gauze before inserting into wound bed
      4. Pastes easier to remove from wound

   7. Calcium alginate (produced from seaweed)

      1. Absorbent
      2. After absorbing exudate, converts into viscous hydrophilic gel: biodegradable
      3. Used to pack wounds, especially for tunneling
      4. Requires secondary dressing
      5. Halodorous after combining with drainage

Images used with permission of Dave Arnell