PT Classroom - The use of Electrical Stimulation in Physical Therapy Wound Care ׀ by  Erica Swanson, DPT

The positive effects of electrical stimulation for the treatment of wounds have been demonstrated for centuries. While methodology of treatment has evolved, research continues to show the benefits of delivering bioelectrical currents to healing tissues. Physical Therapists have a great understanding of anatomy and the use of physical technologies to facilitate the healing process. Major findings support the use of electrical stimulation for chronic wounds in Physical Therapy practice.

Many research studies have demonstrated the existence of a skin battery; meaning the skin and its subdermal tissues have a voltage and charge difference that allow ions and charged molecules to move based on their electrochemical characteristics (1,2,3). Tissue injury through the skin causes current to escape and as the tissue dries out this “current of injury” disappears; preventing the wound bed from receiving the appropriate resources it requires to repair (2, 4).

Cellular synthesis and metabolism are important factors in tissue healing and electrical stimulation. High volt pulsed current has been shown to increase the migration of cells and ions to the site of application. DNA and collagen synthesis in fibroblasts can increase up to 160% after 14 days of treatment with maximum synthesis with the cathode between 50 and 75V and 100 PPS (pulses per second) (5). This helps wounds heal more rapidly. There are also reports of increased calcium uptake and increased production of insulin receptors on the fibroblast membrane (6). Galvanotaxis is the process where cells (positive or negative in charge) move toward oppositely charged electric field (7). This finding makes the selection of the electrode polarity used in electrical stimulation an important parameter to consider.

The cathode (negative electrode) and the anode (positive electrode) have different and essential effects on the wound based on what cells they attract. The cathode attracts anions (negatively charged ions) while the anode attracts cations (positively charged ions). Cells attracted to the cathode include neutrophils fibroblasts, and epidermal cells (9, 10). The effects of using the cathode include re-epithealization and a non-painful, selective removal of nonviable tissue called autolytic debridement (7). Macrophages are an example of cells attracted to the anode (8). The anode can promote the formation of granulation tissue and decrease inflammation and infection within the wound bed (11). Research has indicated that the use of either electrode will increase blood flow, increase the partial pressure of oxygen in the local wound area and facilitate overall wound healing (12, 13). There is also evidence to support alternating polarity of the electrodes every 7 days (14).

When selecting the appropriate voltage to use the research indicates optimal healing with sub-motor intensity of current (5). Frequency and duration recommendations vary in the literature with a majority of treatment times between 45-60 minutes, 3-7 times a week (11). High Volt Pulsed Current (HVPC) is the most commonly used mode of electrical stimulation for wound care, however, some research indicates the use of Direct Current (DC) for antiseptic effects (15).

The use of electrical stimulation in wound care requires a specific clinical judgment and setup prior to treatment. A physical therapist must always consider the population of patients that are not appropriate for a specific treatment. Contraindications to the use of electrical stimulation for wound care include Osteomylitis that is untreated with antibiotics, malignancies near or on the wound, active bleeding, Pacemaker, or the presence of substances containing iodine or metal ions. Before the start of treatment, the wound bed, including the undermining, should be cleaned and packed loosely with saline soaked gauze that has been fluffed or peeled apart. The appropriate size electrode is placed on the gauze and covered with more saline soaked gauze. The indication for the use of this modality is chronic, non-healing wound that is unresponsive to at least 30 days of conservative wound care (11). Also, electrical stimulation must be used with standard wound care treatment such as dressing changes and debridement and will be compensated only after standard wound therapy has been attempted for no less than 30 days without objective measurable signs of improved healing.

Medicare has issued a National Coverage Determination relating to the use of electrical stimulation for chronic wound care. This states that Medicare will reimburse this service for chronic stage III or IV pressure ulcers, arterial ulcers, diabetic ulcers, and venous stasis ulcers. Medicare defines chronic ulcers as those that have not healed within 30 days of occurrence. Medicare requires the use of the CPT code G0281 to report electrical stimulation for the treatment of wounds. Because this is an unattended modality code, time management and delegation of wound care duties across a multidisciplinary team is important.

There is a wealth of research that supports the benefits electrical stimulation offers patients with chronic wounds. However, many patients are not informed of this treatment option due to the time-consuming treatment regimen and low potential of reimbursement for the practitioner. It is the physical therapists duties to use evidence based practice with all anatomical systems and educate patients about all possible treatment options.