Enhanced healing of diabetic foot ulcers using local heat and electrical stimulation for 30 min three times per week.

BACKGROUND: Electrical stimulation (ES) with heating is effective in healing chronic wounds. However, it this effect due to ES alone or both heating and ES? The aim of the present study was to deduce the individual roles of heat and ES in the healing of chronic wounds. METHODS: The study was performed on 20 patients (mean age 48.4 ± 14.6 years) with non-healing diabetic foot ulcers (mean duration 38.9 ± 23.7 months) who received local dry heat (37°C; n = 10) or local dry heat + ES (n = 10) three times a week for 4 weeks. Patients were given ES using biphasic sine wave stimulation (30 Hz, pulse width 250 µs, current approximately 20 mA). RESULTS: Skin blood flow in and around the wound was measured with a laser Doppler flow imager. In the ES + heat group, the average wound area and volume decreased significantly by 68.4 ± 28.6% and 69.3 ± 27.1%, respectively (both P < 0.05), over the 1-month period. During the average session, blood flow increased to 102.3 ± 25.3% with local heat and to 152.3 ± 23.4% with ES + heat. In the group receiving treatment with local heat only, wounds that had not healed for at least 2 months showed 30.1 ± 22.6% healing (i.e. a decrease in wound area) after 1 month. Although this level of healing was significant, it was less than that observed in the ES + heat group (P<0.05). CONCLUSIONS: Local dry heat and ES work well together to heal chronic diabetic foot wounds; however, local heat would appear to be a relevant part of this therapy because ES alone has produced little healing in previous studies.

The combined effect of a three-channel electrode delivery system with local heat on the healing of chronic wounds.

BACKGROUND: Historically, electrical stimulation (ES) has been used as a treatment for wound care. However, some studies show wounds healing with ES, whereas others do not. Part of the difficulty can be resolved by using heat to help dilate blood vessels, but an inherent problem with ES is uneven currents across the wound due to the use of only two electrodes. Therefore, we designed and tested a multi-electrode ES device in combination with local warming of the wound in non-healing chronic ulcers. STUDY DESIGN: Eighteen subjects (mean +/- SD age, 35.7 +/- 21.3 years) with chronic ulcers (no healing for 26.1 +/- 24.6 months) received ES treatment three times a week for 4 weeks. A heat lamp was used before and during ES to keep the wound and area surrounding the wound warm (37 degrees C). ES was applied for 30 min with biphasic sine wave stimulation at a frequency of 30 Hz, pulse width of 250 micros, and current of about 20 mA. Skin blood flow (BF) in and around the wound was measured with a laser Doppler imager. Wound size was measured prior to each treatment. RESULTS: Over the 1-month period, the mean wound area significantly decreased by 43.4 +/- 44.5% (P < 0.05), and wound volume decreased by 57.0 +/- 27.9% (P < 0.05). Skin BF significantly increased after application of ES and local heat (P < 0.05). The skin BF response decreased as time progressed and the wound healed. CONCLUSIONS: Thus, in this pilot study, application of a three-channel ES system in combination with local heat is effective in the healing of non-healing chronic wounds. Future studies should examine a larger population with variables such as treatment duration, number of days, or length of treatment to optimize the effect of ES on healing of non-healing chronic wounds.

A new electrode design to improve outcomes in the treatment of chronic non-healing wounds in diabetes.

BACKGROUND: Chronic wounds are life-threatening in people with diabetes. Some studies show that electrical stimulation (ES) can help wounds heal, while others do not. But, ES is usually applied using a two-electrode system, where current distribution is greatest in the center line between the electrodes. In the present study, a three-electrode system (three-channel ES) was developed. Current dispersion on the skin and in the quadriceps muscle was compared between the conventional two-electrode and three-electrode systems in controls and tested for its ability to heal chronic wounds in people with diabetes. METHODS: In controls, current was delivered via a biphasic sine wave at a frequency of 30 Hz and pulse width of 100 microseconds. Stimulation electrodes 5 cm x 5 cm and 5 cm x 10 cm were placed at 10 cm and 15 cm separation distances above the quadriceps muscle. Skin currents were measured using five pairs of surface electrodes positioned in five separate locations on the skin. Muscle currents were measured using three pairs of needle electrodes positioned in three different locations in the muscle belly. In chronic wounds in eight subjects with diabetes, stimulation was applied for 1 month, and healing and blood flow were measured. RESULTS: Current during three-channel ES was dispersed more evenly and more deeply than with conventional two-channel ES (P < 0.05). In wounds, there was almost complete healing in 1 month, and current was uniform in the wound. CONCLUSIONS: Three-channel ES is more effective than two-channel ES in terms of better current dispersion across the skin and penetration into tissue and will probably be better for wound healing.