There are many local and systemic factors that affect wound healing. The physician should be actively working to correct any abnormality that can prevent or slow wound healing.

Local Factors

A health care provider can improve wound healing by controlling local factors. He or she must clean the wound, debride it, and close it appropriately. Avulsion or crush wounds  below under general management of wounds) need to be debrided until all nonviable tissue is removed. Grossly contaminated wounds should be cleaned as completely as possible to remove particulate matter (foreign bodies) and should be irrigated copiously. Bleeding must be controlled to prevent hematoma formation, which is an excellent medium for bacterial growth. Hematoma also separates wound edges, preventing the proper contact of tissues that is necessary for healing.
Radiation affects local wound healing by causing vasculitis, which leads to local hypoxia and ischemia. Hypoxia and ischemia impede healing by reducing the amount of nutrients and oxygen that are available at the wound site. Infection decreases the rate of wound healing and detrimentally affects proper granulation tissue formation, decreases oxygen delivery, and depletes the wound of needed nutrients. Care must be taken to clean the wound adequately. All wounds have some degree of contamination, if the body is able to control bacterial proliferation in a wound, that wound will heal. The use of cleansing agents (the simplest is soap and water) can help reduce contamination. A wound that contains the highly virulent streptococci species should not be closed. Physicians should keep in mind the potential for Clostridium tetani in wounds with devitalized tissue and use the proper prophylaxis.

Systemic Factors

In addition to controlling local factors, the physician must address systemic issues that can affect wound healing. Nutrition is an extremely important factor in wound healing. Patients need adequate nutrition to support protein synthesis, collagen formation, and metabolic energy for wound healing. Patients need adequate vitamins and nutrients to facilitate healing; folic acid is critical to the proper formation of collagen. Adequate fat intake is required for the absorption of vitamins D, A, K, and E. Vitamin K is essential for the
carboxylation of glutamate in the synthesis of clotting factors II, VII, IX, and X. Decreasing clotting factors can lead to hematoma formation and altered wound healing. Vitamin A increases the inflammatory response, increases collagen synthesis, and increases the influx of macrophages into a wound. Magnesium is required for protein synthesis, and zinc is a cofactor for RNA and DNA polymerase. Lack of any one of these vitamins or trace elements will adversely affect wound healing. Uncontrolled diabetes mellitus results in uncontrolled hyperglycemia, impairs wound healing, and alters collagen
formation. Hyperglycemia also inhibits fibroblast and endothelial cell proliferation within the wound. Medications will also affect wound healing. For example, steroids blunt the inflammatory response, decrease the available vitamin A in the wound, and alter the deposition and remodeling of collagen. Chronic illness (immune deficiency, cancer, uremia, liver disease, and jaundice) will predispose to infection, protein deficiency, and malnutrition, which, as noted previously, can affect wound healing. Smoking has a systemic effect by decreasing the oxygencarrying capacity of hemoglobin. Smoking may also decrease collagen formation within a wound. Hypoxia results in a decrease in oxygen delivery to a wound and retards healing.