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CHAPTER 32 Skin Integrity & Wound Healing
Primary intention
A
Sutured early
Results in hairline scar
Clean wound
Secondary intention
B
Wound gaping and irregular Granulation occurring
Epithelium fills in scar
Tertiary intention
FIGURE 32-4 A, In a wound with minimal tissue loss, the edges may be sutured together, resulting in rapid healing and minimal scarring. B, A wound that heals by secondary intention heals from the inner layer to the surface. Healing takes longer, and there is scarring. C, A wound that heals by tertiary intention is initially healed by secondary intention and later sutured.
C
Granulating tissue sutured together
Wound not sutured
Granulation partially fills in wound
Tertiary intention healing creates less scarring than secondary healing but more scarring than primary intention healing. Phases of Healing Wound healing occurs in three stages: inflammatory, proliferative, and maturation (Fig. 32-5). Inflammatory Phase—Cleansing This phase lasts from 1 to 5 days and consists of two major processes: hemostasis and inflammation. ■ Hemostasis. At the time of injury, tissue and capillar- ies are destroyed, causing blood and plasma to leak into the wound. Area vessels constrict to limit blood loss. Platelets aggregate (clump together) to slow bleeding. At the same time, the clotting mechanism is activated to form a blood clot. ■ Inflammation. The inflammatory reaction is charac- terized by edema, erythema, pain, temperature ele- vation, and migration of white blood cells into the wound tissues. Within 24 hours, macrophages begin engulfing bacteria (phagocytosis) and clearing debris. Along with plasma proteins and fibrin, they form a
■ Secondary Intention Healing. This occurs when a wound (1) involves extensive tissue loss that prevents wound edges from approximating or (2) should not be closed (e.g., because of infection). Because the wound is left open, it heals from the inner layer to the surface by filling in with beefy-red granulation tissue (a form of connective tissue with an abundant blood supply) (Fig. 32-4B). Healing epithelial tissue may appear in the wound as small pink or pearl-like areas. Key Point: Wounds that heal by secondary intention heal more slowly, are more prone to infection, and develop more scar tissue. ■ Tertiary Intention Healing. Also called delayed pri- mary closure, this occurs when two surfaces of gran- ulation tissue are brought together (Fig. 32-4C). This technique may be used when the wound is clean- contaminated or contaminated. Initially, the wound is allowed to heal by secondary intention. When there is no evidence of edema, infection, or foreign mat- ter, the wound edges are closed by bringing together the granulating tissue and suturing the surface. Such wounds require strict aseptic technique during all dressing changes because they are prone to infection.
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