Effects of electrical stimulation on wound healing in patients with diabetic ulcers.

OBJECTIVE: To evaluate the effects of two stimulation waveforms on healing rates in patients with diabetes and open ulcers. The hypothesis was that stimulus waveforms with minimal polar characteristics would provide significant healing for this patient sample. RESEARCH DESIGN AND METHODS: This was a prospective study that enrolled 80 patients with open ulcers. Patients received stimulation with either an asymmetric biphasic (A) or symmetric biphasic (B) square-wave pulse. Amplitudes were set to activate intact peripheral nerves in the skin. Two other groups received either very low levels of stimulation current (MC), or no electrical stimulation (C). When combined these groups were referred to as the control group. Treatment was carried out daily until the wound healed, the patient withdrew from the study, or the physician changed the overall wound management program. Average healing rates were calculated from weekly measures of the wound perimeter and were used for statistical comparison through a one-way analysis of variance. RESULTS: Stimulation with the A protocol significantly increased the healing rate, enhancing healing by nearly 60% over the control rate of healing. Stimulation with the B protocol did not increase the healing rate when compared with control subjects. CONCLUSIONS: Electrical stimulation, given daily with a short pulsed, asymmetric biphasic waveform, was effective for enhancement of healing rates for patients with diabetes and open ulcers.

Effect of electrical stimulation waveform on healing of ulcers in human beings with spinal cord injury.

Various electrical stimulation waveforms have been used to enhance wound healing, with little consideration for potential differences in their physiologic effect. The present study evaluated the effect of stimulation waveform and electrode placement on wound healing. Eighty patients with spinal cord injury and one or more pressure ulcers were treated. A total of 185 ulcers received 45 minutes of stimulation daily. Each ulcer was subjected to one of four treatment protocols: asymmetric biphasic waveform, symmetric biphasic waveform, microcurrent stim-ulation, or a sham control protocol. Electrodes were placed outside the wounds, over intact skin and surrounding the area of the ulcer. Data were categorized by ulcers which healed during the protocol and those which did not. Analysis of the "good response" ulcers (n = 104) showed significantly better healing rates for those receiving stimulation with the asymmetric biphasic waveform, compared with the control and microcurrent groups. Mean healing rates from the present study were similar to previously reported measures. The waveforms studied possessed minimal polar capabilities, and the electrodes were placed outside the wound. These data show that electrical stimulation clearly enhanced healing of pressure ulcers in a significant number of individuals with spinal cord injury; the physiologic implications of these findings relative to the mechanism(s) by which electrical stimulation enhances wound healing are discussed. However, extrapolation of these results to patients with other types of wounds must await further study.