PROCEDURE 124 • The skin is the largest organ of the body and has two major tissue layers. The outermost layer, the epidermis, is made of stratified, squamous cells with keratin and melanin. This layer protects against environmental exposure, restricts water loss, and gives color. The inner layer, the dermis, is made of fibroelastic connective tissue with capillaries, lymphatics, and nerve endings and provides nourishment and strength. The layer beneath the dermis is the subcutaneous tissue, composed of areolar and fatty connective tissue to provide insulation, shock absorption, and calorie reserve. • The natural components of wound healing include three overlapping phases of healing: inflammation, proliferation, and maturation. • Wound healing occurs via primary or secondary intention. • Primary intention is used with limited tissue loss; the wound is clean, and the wound edges can be approximated and closed, frequently with sutures or staples. • Secondary intention is used when either a large amount of tissue has been lost or the wound is contaminated.21 Wound dressing techniques are used to clean the wound and encourage development of granulation tissue and reepithelialization for wound closure. • The goals of primary wound closure are to stop bleeding, prevent infection, preserve function, and restore appearance. • Principles of proper wound closure include the following: • Risk factors for surgical site infections include intrinsic factors (such as age, active skin condition, smoking status, body mass index, and comorbidities) and extrinsic factors (e.g., preoperative, perioperative, and postoperative patient care practices, such as preoperative skin preparation and postoperative dressings).14 Risk factors for infection in a traumatic laceration include extremes of age, history of diabetes mellitus, chronic renal failure, jagged wound edges, stellate shape, visible contamination, injury deeper than the subcutaneous tissue, and presence of a foreign body.10,15,18 • Hair removal around suture site is not necessary before suturing unless the hair interferes with the procedure. Removal of hair has been associated with higher risk of infection. If hair must be removed, an electric clipper is preferred. A razor can cause abrasions and microscopic skin nicks that may increase the risk of infection.6,14,16,19 • Depending on the clinical setting, referral to an appropriate specialist (e.g., vascular, orthopedic, plastic, or general surgeon) may be warranted for wounds with damage to the blood supply, nerves, or joint; wounds on the face; or wounds with extensive tissue damage or infection. • Wounds contaminated or infected with saliva, feces, or purulent exudate or that have been open longer than 8 hours may benefit from delayed closure on or after the fourth day to decrease the risk for infection. • Wounds may be closed with several techniques: sutures, staples, adhesive skin strips (i.e., Steri-Strips, or skin adhesives.
Wound Closure
PREREQUISITE NURSING KNOWLEDGE
Inflammation: Wound extends through the epidermis, disrupts blood vessels, and exposes collagen, activating the clotting cascade and inflammatory response. Vascular and cellular responses are designed to protect the body against foreign substances and limit blood loss via vasoconstriction and development of a clot providing hemostasis. The inflammatory response activates macrophages and clears the wound of cellular debris. Hemostasis with fibrin formation creates a protective wound scab. Kinins and prostaglandins produce local vasodilation and increase permeability of the vasculature, thereby promoting development of inflammatory exudate. Inflammation brings chemical stimuli for wound repair. Wounds left open for 3 hours show a dramatic increase in vascular permeability, which results in thick inflammatory exudate and may limit the therapeutic value of antibiotics.5,21
Proliferation and epithelialization: This phase of wound healing is characterized by generation of new tissue, angiogenesis, and collagen formation. After an incision, the divided parts of the epithelium are closed by cellular migration and mitosis, forming an epithelial bridge that protects the wound against bacteria. When the skin edges are slightly everted with suturing, epithelial bridging occurs within 18 to 24 hours. Wounds that have approximated skin edges may take 36 hours to epithelialize. If the edges are inverted, it may take up to 72 hours to completely epithelialize.5
Elimination of dead space where serum and blood can accumulate, thus decreasing the risk for infection
Avoidance of tissue ischemia and strangulation from tying sutures too tightly
Staples provide the strongest closure, skin adhesives and sutures are next strongest, and adhesive skin strips are the weakest.1
Adhesive skin strips (i.e., Steri-Strips) and skin adhesives are found to be equal in cosmetic outcomes and acceptability.12,15 They are best used on wounds that are not under tension.
Skin adhesives such as 2-octyl cyanoacrylate (Dermabond, Ethicon, Inc.) have been shown to be equivalent to sutures in repair of simple, clean wounds on children. Adhesives should not be used over joints; on hands, feet, lips, or mucosa; on infected, puncture, or stellate wounds; or in patients with poor circulation or a propensity to form keloids.6 They are best suited for short (less than 6 to 8 cm), low-tension, clean-edged, straight to curvilinear wounds that do not cross joints or creases.2,7,8
Curved needles are either tapered or cutting. Needles used for skin closure have an angle of 135 degrees.
Sutures are absorbable or nonabsorbable, braided, or monofilament.
Absorbable suture (i.e., natural gut, synthetic polymers) is used for layered closures. Gut suture is broken down via phagocytosis and induces a moderate inflammatory reaction. Chromic gut suture has increased strength and lasts longer in tissue, but it is not used on the skin because it can cause a severe tissue reaction. Synthetic absorbable sutures are favored over gut because of decreased infection rates and increased strength and longevity.3Related posts:
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