Wound debridement, care and healing
Successful wound management with rapid and complete healing and minimal complication depends on understanding the basic principles of assessment, bacteriology and application of the general principles of wound care. The primary goal of wound management is to aid the natural body process to produce optimal functional and cosmetic result. This requires an understanding of the basic principles of wound care and the process of healing. Failure to do this may result in delay of healing and unwanted secondary complications which may be distressing to the physician, patient and family and may lead to greater economic loss.
Wound is defined as a break in the normal continuity of a tissue. It is caused by a transfer of any form of energy into the body which can be either to an externally visible structure like the skin or deeper structures like muscles, tendons or internal organs.
Generally, do not close wounds by primary suture if they are or may be contaminated, and do not touch an open wound directly with bare, unsterilized hands. A repaired wound can be regarded as sealed after 24 hours, and dressings may then be changed without sterile gloves but with a “no-touch” technique.
Remove dressings over closed wounds if they become wet or if the patient shows signs or symptoms suggestive of infection, for example fever or unusual wound pain. After removing the dressing, inspect the wound for signs of infection and sample any discharge for bacteriological examination.
Keeping accurate records on patients is the doctor’s responsibility. Write down all clinical information about the patient immediately after such information is obtained. Indicate the date and time for every record made, and ensure that all records are legible and easily understood. Notes on surgical procedures undertaken, including the findings at operation and instructions on postoperative management, must be recorded without delay at the end of every operation. Specific mention should be made of the operation as being either “clean”, “clean-contaminated”, “contaminated”, or “dirty and infected”. This will allow for an evaluation of postoperative wound infection rates. Such evaluation, which should be the regular duty of one member of the hospital team, permits assessment of the application of aseptic routine within the hospital.
Even ward patients who are not seriously ill should be assessed at least once a day and progress notes made, if only to indicate that there has been no change in the patient’s condition. On discharging the patient from the ward, record the definitive diagnosis and give instructions about his or her further management as an outpatient. Remember that clinical notes are important for review and discussion to determine how patients (including future patients) should be managed, for insurance and medico-legal purposes, and for research.
Debridement is a procedure used in the initial management of non-surgical wounds to remove dead tissue and foreign material in order to facilitate healing. Wound toilet and debridement are systematic procedures, applied first to the superficial and then to the deeper layers of tissues. Gentle handling of tissues will minimize bleeding, which can be further controlled by local compression or by ligation of the spurting vessels.
Anaesthesia should be provided as appropriate. If necessary, clip or shave hair from around the wound. Wash the wound with toilet soap and water, irrigate it with physiological saline, and scrub the surrounding area thoroughly. There should be no soap left in the wound. Meticulously remove any loose foreign material such as dirt, grass, wood, glass, or clothing and prepare the skin with antiseptic. It is generally wise to extend the wound longitudinally to reveal the ·full extent of damage. Excise only a very thin margin of skin from the wound edge
Excise all dead tissue from the wound. Dead or devitalized muscle will be dark in colour and will be soft or easily torn and damaged; it will not contract when pinched with toothed forceps or bleed when cut. Remove all adherent foreign material along with the dead muscle. In cases of compound fracture, remove only very small, obviously free fragments of bone, provided that their removal does not affect the stability of the fracture. It is unwise to strip muscle and periosteum from a fractured bone.
Vessels, nerves, and tendons that are intact should be left alone after the wound has been cleansed. Ligate divided vessels regardless of whether they are bleeding. Large vessels that have been damaged and contused may need to be divided between ligatures, but first test the effect on the distal circulation by temporary occlusion of the vessel with tape or rubber clamps.
Wound healing is a complex biologic process of restoring normal tissue continuity. There are integrated sequences of events leading to cellular proliferation and remodeling. under normal conditions it starts immediately following the event of wounding and passes through basic mechanisms with the following four phases in all wounds.
Phases of healing
Coagulation phase: This is the first phase of healing which is induced immediately following injury. It is characterized by vaso-constriction, clot formation and release of platelets and other substances necessary for healing and help as a bridge between the two edges.
Inflammatory phase: This phase takes place from time of wounding up to three days. It is characterized by classical inflammatory response, vasodilatation and pouring out of fluids, migration of inflammatory cells and leukocytes and rapid epithelial growth.
Proliferate Phase: This phase, also known as phase of fibroplasia, starts around the 3rd day of injury and stays for about three weeks. This is a phase during which important events occur for healing of the wound. It is characterized by fibroblast, epithelial and endothelial proliferation, Collagen synthesis, and ground substance and blood vessel production.
Maturation phase: Also known as phase of remodeling, this takes the longest period which may extend for up to one year. Equilibrium between protein synthesis and degradation occurs during this phase with cross linking of collagen bundles leading to slow and continuous increase in tissue strength of the wound to return to normal.
Clinical types of healing
Traditionally, wound healing can be classified into three clinical types: Healing by first, second and third intention.
Healing by first intention: This is a type of healing of clean wound closed primarily to approximate the ends. Healing takes place by epithelialization and leaves minimal scar.
Healing by Second intention: This occurs in wide, contaminated wounds, which are not primarily closed. Healing takes place by granulation tissue formation, tissue contraction and epithelialization.
Healing by third intention: This occurs in wounds which are left open initially for various reasons and closed later (delayed primary closure)
Factors affecting healing
Healing of a wound can be affected by various conditions. The following are examples of factors which down grade a healing process.
- Ischemia and decreased oxygen tension
- Presence of foreign bodies
- Closure under tension
- Systemic diseases like diabetes, cirrhosis, renal failure, malignancy
- Poor nutritional State (hypo proteinemia vitamin and mineral deficiency)
- Decreased resistance due to immune suppression, chronic infection
- Drug therapy like steroids, cytotoxic agents
Classification of wounds
Once wound is carefully assessed, it is necessary to classify into a specific type in order to plan a proper management scheme. There are many approaches of classifying wounds. However, wounds can generally be grouped into two categories.
Closed wounds: These are wound types, which have an intact epithelial surface, and skin cover not completely breeched. Example: Contusion, Bruise, Hematoma
Open wounds: These are wounds caused by injury which leads to a complete breakt of the epithelial protective surface. Example: Abrasion, Laceration, Puncture, Missile injuries, Bites.
The following method is the traditional surgical wound classification scheme that was introduced in 1964. This method classifies wounds according to the likelihood or rate of wound infection.
Clean: Non-traumatic, non-infected wound, no break in sterility technique, the respiratory, gastrointestinal or genitourinary tracts not entered.
Clean-contaminated: Minor break in technique, oropharynx entered, gastrointestinal or respiratory tracts entered without significant spillage, genitourinary or biliary tracts entered in absence of infected urine or bile.
Contaminated: Fresh traumatic wounds, major break in sterility, gross spillage from gastrointestinal tract, and entrance of genitourinary or biliary tracts in the presence of infected urine or bile
Dirty and Infected: Acute bacterial inflammation without pus, wound with heavy contamination and evidence of infection, transection of “clean” tissue for the purpose of surgical access for collection of pus, traumatic wound with retained devitalized tissue, foreign bodies, fecal contamination, and/or delayed treatment, or from dirty sources