NEW MODALITIES IN MANAGEMENT OF CHRONIC WOUNDS

Abstract

A chronic wound is a wound that does not heal in an orderly set of stages and in a predictable amount of time the way most wounds do; wounds that do not heal within three months are often considered chronic. Chronic wounds seem to be detained in one or more of the phases of wound healing. For example, chronic wounds often remain in the inflammatory stage for too long. In acute wounds, there is a precise balance between production and degradation of molecules such as collagen; in chronic wounds this balance is lost and degradation plays too large a role. Healing of acute wounds normally proceeds through well-defined phases of hemostasis, inflammation, proliferation, and remodeling In addition to poor circulation, neuropathy, and difficulty moving, factors that contribute to chronic wounds include systemic illnesses, age, and repeated trauma. Comorbid ailments that may contribute to the formation of chronic wounds include vasculitis, immune suppression, and diseases that cause ischemia. Emotional stress can also negatively affect the healing of a wound, possibly by raising blood pressure and levels of cortisol, which lowers immunity. Chronic wounds seem to be detained in one or more of the phases of wound healing. For example, chronic wounds often remain in the inflammatory stage for too long The majority of chronic wounds are covered with nonviable tissue, including callus, eschar, fibrinous material, and slough. This tissue has no regenerative capability, harbors bacteria, and prevents the migration of healthy epithelium into the wound. Debridement is required to excise nonviable tissue and should be aggressive, particularly at the initial evaluation. Cellular senescence has been identified in wound tissue around diabetic foot ulcers and chronic venous ulcers of long duration, indicating the need for wound excision to remove all surrounding tissue in these cases. In general, the management of bacterial colonization of chronic ulcers remains a controversial area with limited high quality research and contradictory results in the studies available for review. Although there is general agreement among experts that wounds with obvious signs of clinical infection should be treated with systemic antibiotics, there is no consensus on the management of wounds colonized with bacteria or bacterial biofilms without signs of systemic infection. The definition of a critically colonized wound is not universally standardized and may vary depending on the virulence of the colonizing bacteria. It is estimated that more than 5000 products are currently marketed as wound dressings for acute or chronic wounds. In general, the selection of a wound dressing should be based on the type of wound. Moisture balance is important, and the dressing should maintain a moist environment conducive to tissue growth and epithelial migration. Based on the high concentration of inflammatory cytokines and proteases in chronic wound fluid, excessive fluid should be wicked away from the ulcer and the skin surface to prevent further tissue inflammation and damage from prolonged contact. A multitude of agents with theoretical healing benefits have been added to wound dressings, including collagen, zinc, enzymes, copper, chlorophyll, honey, avocado oil, and others with little proof of benefit. Table lists the common categories of wound dressings and their typical uses. Negative-pressure wound therapy (NPWT) devices are designed to apply controlled suction to a wound bed at continuous or intermittent pressure settings to stimulate wound closure. Negative pressure can result in numerous alterations in the wound environment, including removal of excess exudate containing high concentrations of proteases and inflammatory cytokines, stimulation of senescent cells, mobilization of macrophages, and stimulation of angiogenesis. Hyperbaric oxygen (HBO) therapy involves treating the patient with 100% oxygen at elevated atmospheric pressures in a specially designed chamber. The benefits of increasing the partial pressure of oxygen in the tissues may include improved oxygen supply, reduction of inflammation and edema, and inhibition of infection. HBO is reportedly useful in the treatment of a number of wound problems, including osteomyelitis, necrotizing fasciitis, and the healing of tissue flaps. Typical treatment protocols for leg ulcers involve one or two treatments daily for a total of 20 to 40 treatments