Wound Healing, Dressing, and Drains Dr. Aidah Abu Elsoud Alkaissi

Wound healing Etiology of wounds: Surgical: caused by an incision or excision Traumatic: caused by an injury (mechanical, thermal, or chemical) Chronic:caused by an underlying pathophysiology, such as pressure sores, or venous leg ulcers, over time

Exact biologic process that takes place in orderly sequence An exudate containing blood, lymph, and fibrin begins clotting and loosely binds the cut edges together Blood supply to the area is increased, and the basic process of inflammation is set in motion Leukocytes increase in number to fight bacteria in the wound area and by phagocytosis help to remove damaged tissues The served tissue is quickly glued together by strands of fibrin and a thin layer of clotted blood, forming a scab

Wound Healing Plasma seeps to the surface to form a dry protective crust This seal helps to prevent fluid loss and bacterial invasion During the first few days of wound healing, the seal has little tensile (The resistance of a material to a force tending to tear it apart) strength After 3-4 days , connective tissue cells (fibroblasts)rapidly proliferate and give strength to the wound by producing collagen, a tough fibrous protein responsible for the structural integrity of the skin

Wound Healing At the same time small blood vessels regenerate and build new blood channels, granulation tissue (fibrous connective tissue) includes blood vessels and lymphatics that proliferate from the base of the wound Rapidly growing and multiple epithelial cells begin to restore the epithelial continuity of the skin At this stage the wound appears healed, healing is not complete until the granulation tissue organizes into scar tissue

Wound Healing By the ninth or tenth day, the wound is moderately well healed and then becomes progressively stronger The whole process of repair takes 2 weeks or more depending on factors such as physical condition of the patient, size and location of the wound, and stresses put on the incisional area During this time the scar (cicatrix) strengthens as the connective tissue shrinks

Wound Healing The amount of tissue loss, the existence of contamination or infection and damage to tissue are all factors that determine the type of wound healing that will occur Process of healing takes place in one of three ways Healing by primary (first) intention Healing by secondary infection (granulation) Healing by delayed primary closure (third intention)

Healing by primary (first) intention Edges of an incised wound in a healthy person are promptly and accurately approximated Contmination is held to a minimum by impeccable (without fault or error) aseptic technique Trauma to the wound is minimal After suturing , no dead space is left to become site of infection Drainage is minimal

Healing by secondary intention (granulation) When surgical wounds are characterized by tissue loss with inability to approximate wound edges, healing occurs through secondary intention This type of wound is left open and allowed to heal from the inside towared the outer surface In infected wound this process allows the proper cleansing and dressing of the wound as healthy tissue builds up from the inside

Healing by secondary intention (granulation) The area of tissue loss gradually fills with granulation tissue (fibroblasts and capillaries) Scar tissue is extensive because of the size of the tissue gap that must be closed. Contraction of surrounding tissue also takes place Consequently this healing process takes longer than primary intention healing

Healing by delayed primary closure (third intention) This healing process takes place when approximation of wound edges is delayed by 3-5 days or more after injury or surgery The condition contribute to a decision for a delayed closure are: 1. Removal of an inflamed organ 2. Heavy contamination of wound

Factors influencing wound healing The patient´s nutritional status and overall reoperative (To return to health or strength; recover) power Especially significant is an adequate supply of protein, which is necessary for the growth of new tissues, the regulation of the osmotic pressure of blood and other body fluids and the formation of prothrombin, enzymes, hormones and antibodies

Vit C which aids connective tissue production and strong scar formation Scrupulous (extreme care and great effort) aseptic technique must be used to prevent any wound infection-the most common cause of delayed wound healing

Factors influencing wound healing Theories abound as to the genesis of wound infection. Cross – contamination from operating room, post anesthesia care unit and unit personel is believed to be a primary source Aseptic principles and maintenance of operating room environmental conditions are significant factors

Length of time that the wound is open in the operating room has also been mentioned The pat own endogenous flora Rough handling of tissue causes trauma that can lead to bleeding and other conditions conducive to the infection

Factors influencing wound healing Other factors pat age, stress level, presxisting condition as diabetes, anemia, malnutrition, cancer , obesity, advanced age, cardiovascular, respiratory impairments. Overall physiacal and psychological condition

Terms Keloid Proud flesh Gangrene Adhesions Dehiscence Evisceration Please read page 142

Wound Classification Clean wound Clean contaminated wound Dirty or infected wound Please read Page 143

Dressing After surgery the dressing may be applied to the wound please read page 143, 144 145