Chapter 8 Wound Healing and Its Impact on Dressings and Postoperative Care 長庚皮膚科 2015.12.11 R2 劉人鳳
Chapter summary Dressing cover the wound, absorb drainage, moist environment Moist environment epithelial migration, angiogenesis, growth factors retention, autolytic debridement, fibrinolysis, protection, voltage gradient Acute wounds healing Chronic wounds relieve pain, promote autolytic debridement, decrease frequency of changes Dressings, skin grafts and skin substitutes
Functions of Dressings Table 8.1
Functions of Dressings -- Acute wounds Heal in an orderly/timely fashion Moist environment and occlusion -- 40% faster of healing than air exposed Enhancement of epithelial migration: keratinocytes begin to migrate sooner Stimulation of angiogenesis: - angiogenesis-stimulating factors (TNF, heparin) - steep oxygen gradient or hypoxia stimulates capillary growth
Functions of Dressings -- Acute wounds Retention of growth factors: platelet derived growth factor (PDGF), basic fibroblast growth factor (bfgf), transforming growth factor (TGF-b), epidermal growth factor (EGF), interleukin IL-1 Facilitation of autolytic debridement: retained water and proteolytic enzymes Protection of exogenous organisms: physical barrier; neutrophils, lysozymes/globulins; inhibitory to bacteria growth by mildly acidic ph Maintenance of voltage gradients: keratinocyte migration, increase synthesis of growth factors
Functions of Dressings -- Chronic wounds Chronic wounds with underlying pathology (delay in the healing process) Inhibitory to epithelialization, inhibit keratinocyte migration; fails to stimulate DNA synthesis directly; considerably higher protease activity Pain relief, painless wound debridement, containment of wound exudates, reduction in the incidence of complications, and improved quality of life
Box 8.1
Non-adherent fabrics Hydrophobic -- greater occlusive capability Vaseline gauze (The Kendall Co, Mansfield, MA), Xeroform (The Kendall Co), and Telfa (The Kendall Co) Hydrophilic -- less occlusive, facilitate drainage of fluids and exudates Xeroflo (The Kendall Co), Mepitel (Mö lnlycke Health Care, Gothenburg, Sweden), Adaptic (Johnson & Johnson Medical, Arlington, TX), and N- Terface (Winfield Laboratories, Dallas, TX)
Non-adherent fabrics: Absorptive dressings Gauze is one of the most common Secondary dressing to fix Foam dressings and alginates: both absorptive and occlusive/moistureretentive dressings
Occlusive/moisture retentive Moisture vapor transmission rate (MVTR) in 24 hrs MVTR of intact normal skin: 200 g/m 2 per day MVTR of wounded skin: 40X MVTR of <35 g/m 2 per hour are defined as occlusive or moisture retentive.
Non-biologic occlusive dressings
Foam dressings [Advantages] Able to expand to conform to the size and shape of the wound Wounds with unusual configurations Highly absorptive Can be easily removed [Disadvantages] Opaque, require secondary dressing
Foam dressings [Indications] Partial-thickness wounds Moderately to heavily exudative wounds and infected wounds Pressure relief and cushion bony prominences Secondary dressings for additional absorption [Examples] Allevyn (Smith & Nephew United, Largo, FL), Biopatch (Johnson & Johnson Medical), Curafoam (The Kendall Co), Flexzan (Dow B Hickam, Inc, Sugarland, TX), Hydrasorb (The Kendall Co), Lyofoam (ConvaTec, Princeton, NJ), Mepilex (Mö ln-lycke Health Care), Polymem (Ferris Corp, Burr Ridge, IL) [Technique] 2 cm margin, tape or gauze for non-adhesive foam dressing
Film dressings [Advantages] Transparent, bacterial barrier Self-adhesive [Disadvantages] Non-absorptive fluid collection frequent dressing changes Strip away newly formed epidermis on removal Wrinkle easily, hard to handle Contact dermatitis
Film dressings [Indications] Mildly exuding wounds, including lacerations, superficial surgical and burn wounds, donor sites, superficial ulcers, and catheter sites Partial-thickness wounds with minimal exudates Secondary dressings over alginates, foams, and hydrogels NOT used in moderately to heavily exuding or infected wounds, sinus tracts, or cavities [Examples] Tegaderm (3M Healthcare, St Paul, MN), Bioclusive (Johnson & Johnson Medical), Blisterfilm (The Kendall Co), Polyskin II (Kendall Healthcare, Mansfield, MA), Mefilm (Mö lnlycke Health Care), Carrafilm (Carrington Lab, Irving, TX), and Transeal (DeRoyal, Powell, TN) [Technique] Intact periwound skin, 3 4 cm margin
Hydrocolloids [Advantages] Absorbent, create bacterial and physical barrier (waterproof) Hydrophilic particles absorb and form a gel autolytic debridement, enhance angiogenesis, granulation tissue formation, and healing. [Disadvantages] Opaque, gel has unpleasant smell, expensive
Hydrocolloids [Indications] Partial- or full-thickness wounds, mildly to moderately exudative wounds (NOT actively infected) Pressure ulcers, venous ulcers Burn wounds (NOT 3 rd degree) and donor sites Acute surgical wounds [Examples] Duoderm (ConvaTec), NuDerm (Johnson & Johnson Medical), Comfeel (Coloplast, Minneapolis, MN), Hydrocol (Dow Hickam/Bertek), Cutinova (Smith & Nephew), Tegasorb (3M, Minneapolis, MN), Replicare (Smith & Nephew United), and Restore (Hollister, Libertyville, IL) [Technique] >2 cm margin, daily ~ 3-7 days, ZnO for peri-wound skin
Hydrogels [Advantages] Semitransparent, soothing& cooling effect Do not adhere to wounds, hydrating [Disadvantages] Require secondary dressing, frequent dressing changes
Hydrogels [Indications] Painful wounds Partial-thickness wounds Wounds after laser, dermabrasion or chemical peel Donor sites [Examples] Vigilon (CR Bard, Murray Hill, NJ), Nu-gel (Johnson & Johnson Medical), Tegagel (3M), Flexi-Gel (Smith & Nephew), Curagel (The Kendall Co), Clear-Site (Conmed Corp, Utica, NY), Curafil (The Kendall Co), Curasol (Healthpoint), Carrasyn (Carrington Laborato-ries), Elasto-Gel (SW Technologies, North Kansas City, MO), Hypergel (Mö lnlycke Health Care), Normlgel (Mö lnlycke Health Care), SoloSite Wound Gel (Smith & Nephew), 2nd Skin (Spenco Medical, Ltd, Waco, TX), and Transigel (Smith & Nephew). [Technique] changed every 3 days for necrotic wounds, 7 days for granulating wounds. Remove gently.
Alginates [Advantages] Highly absorbent Hemostatic, do not adhere to wounds Fewer dressing changes [Disadvantages] Require secondary dressing, gel has unpleasant smell
Alginates [Indications] Highly exudative wounds Deep wounds, sinuses and cavities (rope and ribbon forms) Partial- or full-thickness wounds After surgery [Examples] AlgiSite (Smith & Nephew), Algosteril (Johnson & Johnson Medical), Kaltostat (ConvaTec), Curasorb (The Kendall Co), Dermacea (The Kendall Co), Melgisorb (Mö lnlycke Health Care), SeaSorb (Coloplast, Holtedam, Denmark), Kalginate (DeRoyal), and Sorbsan (Dow B Hickam, Inc) [Technique] at least 2 mm beyond the wound edges, secondary dressing is needed
Non-biologic occlusive dressings NEWER NON-BIOLOGIC DRESSINGS ARE CLASSIFIED INTO 3 BASIC CATEGORIES
Hydrofibers [Advantages] Soft, absorbent [Indications] Moderately to heavily exuding wounds Wounds that are prone to bleeding Abrasions, lacerations, excisional wounds, pressure or leg ulcers, burns, and graft donor sites, wound cavities (hydrofiber ribbons) [Examples] Aquacel
Collagen dressings [Advantages] Available as particles, sheets, or gels Providing a collagen matrix for cellular migration [Disadvantages] Cause irritation or initially increase drainage [Indications] Moderately exudative wounds and recalcitrant ulcers [Examples] Fibracol (Johnson & Johnson, Skillman, NJ), Medifil (Biocore Medical Technologies, Inc, Silver Spring, MD), and Nugel collagen wound gel (Johnson & Johnson Medical)
Hyaluronic acid dressings [Advantages] Biodegradable, absorbent Accelerates granulation tissue formation and re-epithelialization [Examples] Hyalofil (ConvaTec)
Biologic dressings: grafts
Biologic dressings: grafts Grafts: local blood supply new blood supply from the recipient bed Autografts: donor site to recipient site from the patient Fractional skin harvesting: multiple full thickness cores of skin with small diameter to minimize donor site morbidity Allografts: donors of the same species -- cadaveric skin Composite grafts: at least two different types of tissues, ex: skin and cartilage
Biologic/biosynt hetic dressings: skin substitutes
Cultured epidermal grafts Cultured epidermal autografts: serial subculture of human keratinocytes from the patient s own skin large epidermal sheets sutured onto the recipient s tissue Secondary dressing: mesh gauze for 7-10 days Another outer dressing: absorb wound exudates, change QD or QOD Disadvantages: require a 2 3-week period, fragile, lack a dermal component. short-term stability
Cultured epidermal grafts Cultured epidermal allografts: Neonatal foreskin Growth factors release stimulate migration and multiplication of the recipient s keratinocytes Donor sites, partial-thickness burns, chronic leg ulcers, epidermolysis bullosa, and wounds resulting from tattoo removal
Dermal replacements Cadaveric allograft skin, Biobrane (Smith and Nephew), EZ Derm (Mö lnlycke), Oasis (Healthpoint), and Dermagraft (Shire Regenerative Medicine, St Helier, Jersey) Human cadaver skin -- acellular collagen dermal matrix and an intact basement membrane Can be used alone or in combination with other grafts AlloDerm (Life Cell Co, Woodlands, TX) -- used in combination with STSGs burn wounds and dermal defects, and for periodontal, and plastic and reconstructive surgery
Dermal replacements Biobrane -- bilaminate biosynthetic material made up of silicone film and nylon fabric containing porcine collagen peptides pain relief, healing time, and absorption of exudates EZ Derm -- porcine collagen chemically cross-linked using an aldehyde temporary coverage of partial-thickness wounds (burns and ulcers) Oasis -- porcine small intestinal submucosa longer shelf-life, requiring a secondary dressing for additional protection Integra (Integra LifeSciences Corp, Plainsboro, NJ) -- bovine collagen and chondroitin-6-sulfate covered by a synthetic silicone elastomer approved by FDA for burns (severe burns, insufficient skin available for an FTSG)
Dermal replacements Dermagraft -- neonatal fibroblasts seeded on a 3D polyglactin bioabsorbable mesh with no outer silicone membrane Full-thickness wounds, FDA approved for chronic diabetic ulcers Avoiding the use of non-human tissue Ready availability Less chance of wound contracture and scarring Mesh absorption in 60 90 days
Dermagraft
Composite skin substitutes Contain both epidermal and dermal components Apligraf (Organogenesis, Canton, MA; also known as Graftskin) -- cultured human neonatal foreskin keratinocytes overlying fibroblasts cultured on a dermal matrix of bovine type I collagen Lack immune cells no clinical rejection FDA-approved: venous leg ulcers or neuropathic diabetic foot ulcers
Apligraf
Composite skin substitutes Bilayered cellular matrix (BCM) or OrCel (Forticell Bioscience Inc, New York, NY) -- porous collagen sponge containing cultured keratinocytes and fibroblasts derived from allogeneic cells harvested from neonatal foreskins FDA approved: split-thickness donor sites of burn; recessive dystrophic epidermolysis bullosa
Cell therapies For healing of chronic wounds Solution containing cells is sprayed onto the wound bed Do not require in-vitro tissue engineering (unlike skin substitutes)
Keratinocyte Spray Spray-applied cell therapy Growth-arrested allogeneic neonatal keratinocytes and fibroblasts Phase-2 double-blind randomized trial Superiority of the active treatment over vehicle (p = 0.0446) Lowest concentration and least frequent, administered every 14 days showed the largest improvement (p = 0.0028)
Mesenchymal stem cells derived from bone marrow Bone marrow aspirate in vitro multipotent mesenchymal stem cells A fibrin polymer spray system used to apply the cultured autologous stem cells Difficult-to-heal wounds Chronic lower extremity wounds
Antimicrobial dressings Silver-impregnated dressings broad-spectrum action on bacteria, including against vancomycinresistant enterococci and methicillin-resistant Staphylococcus aureus (MRSA) release antibacterial levels of silver for 3 7 days against fungi and yeast Aquacel Ag (ConvaTec), Contreet (Coloplast), Arglaes (Medline Industries, Mundeline, IL), Acticoat (Smith & Nephew, London, UK), Silverlon (Argentum Medical, Geneva, IL), and Silvasorb (AcryMed, Inc, Portland, OR)
Antimicrobial dressings Cadexomer iodine -- a slow-release formulation of iodine broad-spectrum antibiotic coverage significantly decrease the bacterial load on the wound surface Iodosorb -- a cadexomer iodine ointment antibacterial and an effective debriding agent pressure, venous, and diabetic ulcers
DEBRIDEMENT
Autolytic debridement The body s own enzymes and moisture liquefy necrotic tissue Selective and painless Enhanced with dressings (films, hydrogels, and hydrocolloid dressings) Should be monitored for infection (particularly with anaerobes)
Mechanical & Surgical debridement Mechanical Wet-to-dry dressings: moist dressing is applied to a wound and then removed after drying Non-selective (may traumatize healthy tissue), painful Side-effects of infection with water-borne pathogens and tissue maceration Surgical Rapid and selective Significant amount of necrotic tissue
Enzymatic debridement Proteolytic enzymes Enhance granulation tissue formation and epithelialization No large, high-quality, published randomized controlled trials comparing the efficacy
Maggot therapy (biosurgery) Lucilia sericata (green bottle fly) are the most commonly used maggots for biosurgery Secretion of proteolytic enzymes, digestion of necrotic tissue and bacteria, increase in wound ph Most efficacious in wounds infected with Gram-positive bacteria, including MRSA
POSTOPERATIVE CARE AND WOUND CARE ACUTE WOUNDS
Post-excision wounds healing by primary intention Simple low-or non-adherent gauze dressing secured with tape Vaseline or Aquaphor ointment to make the patient more comfortable Rarely require cleansing (care using saline ) 1 week for sutured wounds to re-epithelialize suture removal -- 4 6 days for the head and neck, 7 days for the upper limbs, 10 days for the trunk and abdomen, and 14 days for the lower limbs
Liquid adhesive bandages Minor lacerations and abrasions, partial-thickness wounds, shave biopsies Traumatic lacerations especially in pediatric patients Nexcare (3M), Band-Aid brand (Johnson & Johnson Medical), and New-Skin (Medtech, Inc, Irvington, NY)
Post-excision wounds healing by secondary intention Shave or tangential removal of skin Randomized controlled trials -- white petrolatum is as safe and effective as bacitracin with less risk for inducing allergy Dressing -- left undisturbed for 48 72 h after surgery, to reduce incidental trauma and contamination Another alternative: occlusive dressings superficial wounds with minimal exudation -- films deeper wounds -- hydrogels or hydrocolloids highly exudative -- foams and alginates
Postoperative care in laser resurfacing
Postoperative care in laser resurfacing Closed technique Occlusive or semiocclusive dressing (such as Flexzan, Vigilon, 2nd Skin, N- Terface) More rapid epithelialization, less pain Combination of the two approaches -- Closed technique being used for the first 48 h, then followed by the open technique
Uncomplicated partial-thickness and full-thickness wounds Moisture-retentive occlusive dressings -- facilitate healing and relieve pain Biologic and biosynthetic skin grafts and skin substitutes STSGs, FTSGs cultured epidermal autografts, AlloDerm, Integra, and Apligraf
POSTOPERATIVE CARE AND WOUND CARE CHRONIC WOUNDS
Venous ulcers The most common form of leg ulcers Compression, edema reduction, and improvement of venous return Bed rest Leg elevation Elevate the affected leg 18 cm above the level of the heart, 2 4 h during the day and night Compression devices occlusive arterial disease should be excluded recommended ankle pressure: 30 40 mmhg
Venous ulcers Compression stockings Difficult in elderly or arthritis patient Compression bandages Elastic bandages the ACE type: reusable, but not self-adherent be applied in a spiral with 50% overlap between turns
Venous ulcers Compression bandages Unna boot semirigid paste bandage, applied with foot at a 90 angle replaced weekly https://www.youtube.com/watch?v =vrgjhdwd5mo
Venous ulcers Four-layer bandage more flexible and absorbent than the Unna boot maintaining evenly distributed pressure long periods of time orthopedic wool layer, a crepe layer, an elastic layer applied in a figureof-eight pattern, and an elastic layer applied in a spiral pattern
Venous ulcers Orthotic device useful in patients who cannot tolerate other compression modalities or who require frequent dressing changes Pneumatic compression For patients unresponsive to conventional compression bandages or stockings
Venous ulcers Moisture-retentive dressings combined with compression therapy may produce more rapid healing rates initially But long-term follow-up has failed to demonstrate any statistically significant advantage over compression therapy alone Meshing of STSGs Shave therapy (excision of ulcers with lipodermatosclerotic tissue) & meshed STSGs FDA approved: Apligraf -- in combination with compression therapy, > 6 months
Arterial ulcers Requires surgical re-establishment of an adequate vascular supply Diabetes mellitus, cigarette smoking, hypertension, and hyperlipidemia should be controlled Moderate exercise may promote development of collateral circulation Elevation of the head of the bed 10 15 cm improves gravity-dependent arterial flow Limbs should be kept warm Good foot care
Diabetic foot ulcers Good wound care proper footwear, the correct antibiotics when needed, avoidance of weight bearing, pressure-relieving aids, debridement as necessary Aggressive revascularization Control of the serum glucose levels Topical antibacterials Saline-moistened gauze Occlusive dressings such as hydrogels, hydrocolloids, and polymers Dermagraft and Apligraf ; Bilayered Cellular Matrix
Pressure ulcers Goal to enhances soft tissue viability and promotes healing of the pressure ulcers Nutrition (espescially protein), immobility, comorbid disease, and protection from fecal or urine soiling Debridement of devitalized tissue, wound cleansing, application of dressings Possible adjunctive therapy with electrical stimulation for stage III and IV unresponsive ulcers Alginates followed by hydrocolloid > hydrocolloid alone Foam dressings or wound fillers to eliminate dead space
OPTIMIZING OUTCOMES Avoid leakage Control pain Prevent maceration: apply zinc oxide paste on the periwound area Minimize odor: odor-absorbing dressings Remove necrotic tissue Ensure patient compliance Check intrinsic factors Keep wound moist, but not wet
PITFALLS AND THEIR MANAGEMENT Infection: antibiotics, practice clean or aseptic techniques, irrigate under pressure, debride to remove necrotic tissue Contact dermatitis Seroma formation Excessive pressure from dressing Excessive granulation tissue: apply pressure, change dressing type, pare with curette, cauterize with silver nitrate Pigmentary alteration Milia or suture granuloma
PRACTICAL APPLICATIONS
SUMMARY Extensive discussion of the different types of dressings currently available, including their advantages, disadvantages, and indications Reviews the technical aspects of applying some types of dressings as well as specific dressings for venous ulcers and techniques for post laser resurfacing care
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