Types of wounds and management.

A very schematically compiled to assist in delivery to students of every level

1. Wounds Types and Their Management Submitted to : Mam Ayesha Submitted by : 15-ARID-4445 dvm 6 th eve

2. Contents: Introduction Types of wounds Wound healing Management of wounds Conclusion

3. Introduction: Injury: It is caused by external noxa that causes cellular and/or tissue trauma and dysfunction. External noxa: mechanical , chemical, radiation or combination of them. Wound: It is a circumscribed injury which is caused by an external force and it can involve any tissue or organ. (surgical and traumatic/accidental).

4. Types of wounds: Wound can be classified based on : Duration Object causing wound Penetration Based on duration: Acute: An acute wound is an injury to the skin that occurs suddenly rather than over time. It heals at a predictable and expected rate according to the normal wound healing process. Chronic: A chronic wound develops when any acute wound fails to heal in the expected time frame for that type of wound, which might be a couple of weeks or up e.g. ulcer, decubitus, burn wound.

5. Conti…. Based on object causing wound: Open wounds: Incision or incised wound: caused by a clean, sharp-edged object such as a knife, razor, or glass splinter. Laceration:  irregular tear-like wounds caused by some blunt trauma. Abrasion: superficial wounds in which the topmost layer of the skin is scraped off. Avulsion: injuries in which a body structure is forcibly detached from its normal point of insertion. Puncture wound:  caused by an object puncturing the skin. Penetration wound: caused by an object i.e. a knife entering and coming out from the skin. Gunshots: caused by a bullet.

6. Conti…. Closed wounds: Hematomas (or blood tumor) – caused by damage to a blood vessel that in turn causes blood to collect under the skin. Hematomas that originate from internal blood vessel pathology are petechiae, purpura, and ecchymosis. The different classifications are based on size. Hematomas that originate from an external source of trauma are contusions also commonly called bruises. Crush injury caused by a great or extreme amount of force applied over a long period of time.

7. Conti…. Penetrating wounds: These result from trauma that breaks through the full thickness of skin; reaching down to the underlying tissue and organs, and includes: Stab wounds : trauma from sharp objects, such as knives Skin cuts Surgical wound : intentional cuts in the skin to perform surgical procedures Gunshot wounds : wounds resulting from firearms

8. Conti…. Non-penetrating wounds: These are usually the result of blunt trauma or friction with other surfaces; the wound does not break through the skin, and may include: Abrasions : scraping of the outer skin layer Lacerations : a tear-like wound Contusions : swollen bruises due to accumulation of blood and dead cells under skin Concussions : damage to the underlying organs and tissue on head with no significant external wound:

9. Conti…. Miscellaneous wounds may include: Thermal wounds: Extreme temperatures, either hot or cold, can result in thermal injuries (like burns, sunburns and frostbite) Chemical wounds: These result from contact with or inhalation of chemical materials that cause skin or lung damage Bites and Stings: Bites can be from humans, dogs, bats, rodents, snakes, scorpions, spiders and tick Electrical wounds: These usually present with superficial burn-like or sting-like wounds secondary to the passage of high-voltage electrical currents through the body, and may include more severe internal damage.

10. Wound Healing: It is biological process that restores tissue continuity after the injury. It is a combination of physical, chemical and cellular events that restore wounded tissue or replace it with collagen which may start immediately after injury or incision. There are four phases of wound healing as inflammation, debridement, repair and maturation During 1 st 3 to 5 days are the lag phase of wound healing because inflammation and debridement predominate in this duration. Healing is influenced by Host factors, wound characteristics, and other external factors.

11. Conti… Inflammatory phase: it is protective tissue response initiated by damage, characterized by Increased vascular permeability. Chemotaxis of circulatory cells. Release of cytokines and growth factors Cells activation(macrophages, lymphocytes, neutrophils and fibroblasts.

12. Conti… injury hemorrhage(cleans and fills wounds immediately after injury) vasoconstriction for 5-10 mints then dilate(by catecholamine's, serotonin, bradykinin,histaine) fibrogen and clotting elements into wound extrinsic clotting pathway activated by thromplastin clot formation by platelet also release platelet aggregation chemoatractants and growth factors

13. Conti… Now fibrin and plasma transudates will fill the wound and plug lymphatic's, localizing inflammation and gluing wound edge together. Then extracellular matrix is formed in presence of activated factor 13 when fibronectin dimers (within clot) become covalently boded to fibrin and themselves. The blood clot formation stabilizes the wound edges and provides strength. It also provides barrier to infection and fluid loss. Scabs formed when blood clot dries which allows healing beneath the surface. Platelets, mast cells and macrophages release growth factors for healing. White blood cells from vessels into wound initiate debridement phase.

14. Conti… Debridement phase: Chemoatractants encourages neutrophils and monocytes to appear in wound neutrophils prevent infection monocytes are the major and phagocytize debris and secretory cells synthesizing infectious agents growth factors participating remodeling and tissue release substances which formation. stimulates monocytes

15. Conti… Now these monocytes become macrophages in wounds at 24-48 hours. Macrophages secret collagenases which remove necrotic tissues, bacteria and foreign materials. secrete chemoatractive and growth factors macrophages further increased by Chemotaxis angiogenesis and matrix production Now platelets release growth factors for fibroblastic activity. Lymphocytes comes at last and secrete soluble factors and improve the rate and quality of tissue repair.

16. Conti… Repair phase: Granulation and epitheliazation happens by previous migrating substances. Wound contraction occurs reducing size of wound after fibroblast, recognizing collagen in granulation tissue and myofibroblast contraction at wound edges. Contraction occurs simultaneously with granulation and epitheliazation but independent of epitheliazation and involves a complex interaction of cells, extracellular matrix and cytokines. During wound contraction the edges are brought closer and stops when the edges of meet together.

17. Conti… Wound contraction is limited if skin around wound is fixed or inelastic. It can be inhibited by myofibroblast function is stopped. It can also be inhibited by anti-inflammatory steroids, antimicrobial drugs and local application of local anesthetics.

18. Conti… Maturation phase: Wound strength reaches to its maximum strength because of scar formation during this phase of healing. Wound maturation starts when collagen has been adequately deposited to wound. Cellularity of granulation tissue is reduced as cells die. Collagen increase in cross linkages increasing wound strength. Type 3 collagen decrease and type 1 collagen increase. Scar will be formed by the less cellular, flatten and soften during maturation.

19. Wound management: Open wound management: Temporarily cover the wound to prevent further trauma and contamination. Assess the traumatized animal and stabilize its condition. Clip and aseptically prepare the area around the wound. Culture the wound. Débride dead tissue and remove foreign debris from the wound. Lavage the wound thoroughly. Provide wound drainage. Promote healing by stabilizing and protecting the cleaned wound. Perform appropriate wound closure.

20. Conti… Initial wound management begins with removal of gross contaminants and copious lavage (Ringer’s solution) using a warm, balanced electrolyte solution, sterile saline, or tap water (500 to 1000 ml) . Wound lavage reduces bacterial numbers mechanically by loosening and flushing away bacteria and associated necrotic debris. Antibiotics or antiseptics (e.g., chlorhexidine or povidone-iodine) in the lavage solution reduce bacterial numbers; however, these agents may damage tissue. Antiseptics have little effect on bacteria in established infections. Lavaging is preferred to scrubbing the wound with sponges.

21. Conti… Bacteria are effectively removed from the wound surface by high-pressure lavage. Traditionally, a 35- or 60-ml syringe and an 18-gauge needle have been thought to generate approximately 7 to 8 psi of pressure. The most consistent delivery method to generate 7 to 8 psi is a 1-liter bag of fluid within a cuff pressurized to 300 mmHg . Higher pressure (70 psi), generated by pulsatile lavage instruments is more effective in reducing bacterial numbers and removing foreign debris and necrotic tissue, but it may drive bacteria and debris into loose tissue planes, damage underlying tissue, and reduce resistance to infection. Bulb syringes or fluid bottles with holes made in the cap do not generate enough pressure to remove bacteria and debris adequately.

22. Conti… Closed wound: Factors to decide wound closure : Amount of time that has elapsed since injury. Degree of contamination. Amount of tissue damage. Completeness of debridement Status of the wound’s blood supply The animal’s health Extent of tension or dead space.

23. Conti… wound should be lavaged, explored, and débrided. Tendons, ligaments, and vessels may be damaged beyond repair. Identifiable tendon ends should be tagged. Apply a hydrophilic bandage that immobilizes the area and promotes formation of a healthy granulation bed. The wounds will initially begin healing by contraction and epithelialization and may heal completely. Disadvantages of healing by secondary intention include contracture with disfigurement, incomplete healing, and fragile epithelial scars with large wounds.

24. Conti… Alternatively, healthy wounds may be repaired by secondary closure or by use of a flap or graft. Secondary closure occurs at least 3 to 5 days after injury, after a healthy granulation bed has formed. Secondary closure involves resecting the granulation bed and skin margins, lavaging the wound, and apposing skin edges. If secondary closure is not possible, a flap or graft can be applied over the defect. After wound closure, an absorbent, non-adherent bandage should be applied to support the wound and absorb exudate. Bandages should be changed once or twice daily if a passive drain is used; if little drainage is expected and if drains are not used, once every 3 to 4 days may be adequate.