جامعة القاهرة كلية الطب البيطري قسم الباثولوجيا

1. Cairo University Fac Of Vet Medi Dep Of Pathology جامعة القاهرة كلية الطب البيطري قسم الباثولوجيا Healing Of Wounds

2. الباحث*محمود حامد محمود أحمد الرقم* 07281 القرقة* الثالثة

3. موضوع البحث HEALING OF WOUNDS

4. Introduction 1. Wound healing is a complex and dynamic process of restoring cellular structures and tissue layers. The human adult wound healing process can be divided into 3 distinct phases: the inflammatory phase, the proliferative phase, and the remodeling phase. Within these 3 broad phases is a complex and coordinated series of events that includes chemotaxis, phagocytosis, neocollagenesis, collagen degradation, and collagen remodeling. In addition, angiogenesis, epithelization, and the production of new glycosaminoglycans (GAGs) and proteolysis are vital to the wound healing milieu. The culmination of these biological processes results in the replacement of normal skin structures with fibroblastic mediated scar tissue. For more information on wound healing, visit Meds cape's Wound Management Resource Center

5. ♣ Categories of Wound Healing ♥ Category 1 2. Primary wound healing or healing by first intention occurs within hours of repairing a full-thickness surgical incision. This surgical insult results in the mortality of a minimal number of cellular constituents ♥ Category 2 3. If the wound edges are not reapproximated immediately, delayed primary wound healing transpires. This type of healing may be desired in the case of contaminated wounds. By the fourth day, phagocytosis of contaminated tissues is well underway, and the processes of epithelization, collagen deposition, and maturation are occurring. Foreign materials are walled off by macrophages that may

6. ♣ Overview of Wound Healing 4. The amalgam of coordinated events that constitute the process of wound healing is quite complex. The steps in the procession of wound healing include inflammation, the fibroblastic phase, scar maturation, and wound contracture.2,3 Wound contracture is a process that occurs throughout the healing process, commencing in the fibroblastic stage.2

7. ♣ Initial phase - Hemostasis 5. Following vasoconstriction, platelets adhere to damaged endothelium and discharge adenosine diphosphate (ADP), promoting thrombocyte clumping, which dams the wound. The inflammatory phase is initiated by the release of numerous cytokines by platelets. Alpha granules liberate platelet-derived growth factor (PDGF), platelet factor IV, and transforming growth factor beta (TGF-b), while vasoactive amines such as histamine and serotonin are released from dense bodies found in thrombocytes. PDGF is chemotactic for fibroblasts and, along with TGF-b, is a potent modulator of fibroblastic mitosis,

8. ♣ Second phase - Inflammation 6. Within the first 6-8 hours, the next phase of the healing process is underway, with polymorphonuclear leukocytes (PMNs) engorging the wound. TGF-b facilitates PMN migration from surrounding blood vessels where they extrude themselves from these vessels. These cells "cleanse" the wound, clearing it of debris. The PMNs attain their maximal numbers in 24-48 hours and commence their departure by hour 72. Other chemotactic agents are released, including fibroblastic growth factor (FGF), transforming growth factors (TGF-b and TGF-a), PDGF, and plasma-activated complements C3a and C5a (anaphylactic toxins). They are sequestered by macrophages or interred within the scab or eschar

9. ♣ Third phase - Granulation 7.This phase consists of different subphases. These subphases do not happen in discrete time frames but constitute an overall and ongoing process. The subphases are "fibroplasia, matrix deposition, angiogenesis and re-epithelialization".4 In days 5-7, fibroblasts have migrated into the wound, laying down new collagen of the subtypes I and III. Early in normal wound healing, type III collagen predominates but is later replaced by type I collagen.

10. ♣ Healing By Blood-Clot 8. Healing by blood-clot differs but little from that just described. It occurs when, in consequence of the edges of a wound not being brought immediately into apposition with each other, the space between them becomes filled with blood-clot, into which white blood corpuscles and plasma cells soon penetrate. By a process of development the latter are resolved into fibrous tissue, which, as in healing by the first intention, form the permanent bond of union between the divided parts. These two modes of union can only be effected where the lips of the wound are undisturbed and all causes of irritation are excluded.

11. ♣ Healing Under A Scab 9. This is nature's method of repairing wounded parts, and in suitable circumstances the best that can be devised. It is well illustrated when, after the surface of the skin has been broken, the blood and other exuded matters are allowed to dry upon it, and form, as they will, a complete defensive covering or scab. In this condition all foreign substances which would irritate and inflame the wound are excluded from it, and so long as this state continues, healing proceeds rapidly without interruption. Anything, however, that inflames and provokes the formation of pus (matter) beneath the scab, interferes with the process and delays reparation.

12. ♣ Management of surgical wound infections 10. The type of surgery (clean, clean/contaminated, contaminated or dirty) will determine the risk level of infection and the likely spectrum of pathogens.  Empirical therapy should be primarily directed against Staphylococcus aureus. If wounds are not grossly infected, they may respond to local measures such as removal of sutures.  Frequent saline bathing should be undertaken and the wound requires a drain to allow healing.  Deep-seated infection related to complicated abdominal surgery may require broad-spectrum antibiotics and investigation for possible surgical intervention

13. ♣ Indications for prophylaxis 11. Prophylaxis is particularly recommended in surgery where there is a high-risk of infection such as abdominal surgery or where the development of infection would be very serious eg. Indications for prophylaxis in clean surgery where infection would be very serious

14. ♣ Disinfection. 12. The O.C. Sanitary Section of the area occupied, is responsible for the disinfection of billets and camps in which cases of the following diseases have occurred:— 1.Scarlet fever 2.Diphtheria 3.Small-pox 4.Cerebro-spinal meningitis 5.Cholera 6.Relapsing fever 7.Typhus The O.C. Sanitary Section will be communicated with by the A.D.M.S. of the Division. The O.C. Sanitary Section will generally demand a fatigue from the R.M.O. to assist him. This fatigue will be provided from the sanitary personnel of the unit. In cases of other infections diseases, disinfection will be carried out by the R.M.O. A spraying apparatus and fluid for use in it will generally be lent by O.C. Sanitary Section when asked for in writing by the R.M.O.

15. When first intention healing does not occur, the wound heals by “second intention.”  This is a slower healing process. As we mentioned last week, healing occurs when cells move in from the border of the wound, one layer at a time. These overlap until the wound is full. As this ‘filler’ tightens and contracts, the edges are pulled together. If this process continues without interference, Second Intention Healing, cause and effect

16. Wound infections are one of the most common complications after surgery. This means that bacteria have started to grow in your wound. If you develop an infection, smoke have diabetes become more painful look red, inflamed or swollen leak or weep liquid, pus or blood smell unpleasant NON Healing Wound

17. This is nature's method of repairing wounded parts, and in suitable circumstances the best that can be devised. It is well illustrated when, after the surface of the skin has been broken, the blood and other exuded matters are allowed to dry upon it, and form, as they will, a complete defensive covering or scab. Healing Under A Scab

18. After the third week, the wound undergoes constant alterations, known as remodeling, which can last for years after the initial injury occurred. Collagen is degraded and deposited in an equilibrium-producing fashion, resulting in no change in the amount of collagen present in the wound. Complete Healing

19. The occurrence of these must be immediately reported to the O.C. of the soldier's Company, Battery, etc., and a note made on the Tally that the case is one of self-inflicted (or suspected self-inflicted wound) by marking it distinctly with the letters "S.I." It must be remembered that a self-inflicted wound may be accidental or intentional, but in either case a Court-Martial will be required. Self-Inflicted and Accidental Wounds

20. Preparatory to dressing a wound, it is frequently found necessary to cut the clothing in order to remove it without aggravating the injury or causing pain to the patient. Although this matter is one for the judgment of the M.O. in each case, these officers will (as far as is consisistent with the welfare of their patients) avoid unnecessary mutilation of clothing, and especially of boots, gum, thigh. Clothing of Wounds

21. The epidermis is continually exposed to the environment and sustains most of the injury to the skin. As a result, it is shed and regenerated on a daily basis. Its major role is to produce the stratum corneum-a waterproof, semi-permeable membrane on the outermost portion of the epidermis that acts to prevent water loss from the tissues it surrounds. When this upper layer is injured-as can occur with minor scrapes and cuts-it simply regenerates itself without scar formation. The same is not true for deeper injuries Our Outer Layer...the Skin

22. healing by second intention is to use a treatment that is beneficial to the process and does a minimum of damage when used.  The wound will heal quicker and the resulting scar will be smaller.  Whether healed by first or second intention, the horse’s recollection of how it hurt itself will have been forgotten long before the wound is healed! End Of Healing

23. Special skin glue can be used to close small wounds that are less than 5cm (two inches) long. Although the glue is waterproof, the area needs to be kept dry for at least five days. The glue usually peels off in five to 10 days. Sometimes for larger (longer) skin cuts, glue is used together with stitches or special self-adhesive skin-closure strips (Steri-strips) to seal the wound Tissue adhesive (skin glue)