Wound Healing

Wound healing

Normal tissue, under normal circumstances, will spontaneously heal when injured. Normal uninjured tissue has an endogenous electrical steady state with a baseline electric potential. When skin is injured it changes its’ electrical balance. An injury to tissue converts the local environment to a more electronegative state. Microcurrents of approximately 100mV/mm are generated at the site of injury. It is believed that this flux in the local biocurrent is the stimulus to heal.

Wound healing occurs in sequential steps. Primary tissue healing allows wounds to properly reconstruct and heal with strong, mature, healthy tissue. Primary healing of tissue requires an adequate blood supply. At the time of injury, there is disruption of the blood supply at the wound. Prior to the onset of primary healing, wound repair elements must be transported to the wound. It is believed that the physiologic current of injury is a transport mechanism for necessary wound healing elements.

Sheridan et al showed that keratinocytes (reparative skin cells) migrate and are attracted in an electrical field to the electronegative pole. Other healing cells including neutrophils, macrophages, fibroblasts, and epidermal cells are electrically charged. They too, respond to galvanic stimulation. Assimacopoulous has proven that accelerated healing occurs with thick, denser scar formation when there is a reestablishment of a lost negative charge at the wound edge. Studies document that wound tensile strength it is increased after application of an exogenous direct current. Furthermore, wounds that have not healed due to a variety of causes have been shown in multiple studies, to heal after exposure to exogenous microcurrent. Rowley and Barranco were able to inhibit bacterial growth including Pseudomonas Aeruginosa and Staphylococcus Aureus with microcurrent. Wound healing is favorably effected by application of microcurrents by enhancing multiple factors that positively effect the local injured environment including an increase in tissue growth factors, increase in fibroblast motility, increase in collagen formation, and enhanced DNA synthesis. Hypertrophic scars or keloids have been reduced in size after application of microcurrents. Silverleaf Medical Products bandage technology produces the microcurrent that has all of the above benefits.

Wounds need a homeostatic environment to heal. Moisture needs to be balanced. Microbial contamination has to be controlled. Adequate vascularity has to be established, nourishing the healing wounds. Host defenses must be maintained so that wounds may heal.

Detriments to normal healing include the presence of nonviable tissue, inadequate healthy host tissue, infection, exuberant inflammation, moisture imbalance (too dry or too wet), non advancing and/or undermined skin edges, immunosuppression, malnutrition, vascular disease, and cigarette smoking.

Wound care is directed towards promoting and providing a favorable healing environment utilizing modalities such as debridement, irrigation, hyperbaric oxygen, whirlpool and ultrasound. Antibiotics are often used topically and systemically in management of wounds. Exogenous growth factors and electric stimulation can also be used as modalities to promote healing.