Pulsed electrical fields in wound healing

For decades, a variety of electrical stimulation (ES) types have been used to promote wound healing [1-3]. Possible mechanisms that may account for enhanced wound healing include bactericidal and bacteriostatic effects [4-6], increased blood flow [7], orientation of new collagen formation [8], and retardation of edema buildup [9]. The influence of ES on wound healing has been assessed in a number of clinical trials that examined continuous microamperage direct current (µADC) [10,11], pulsed µADC [12,13], pulsed milliamperage direct current (mADC) [14-16], and high-voltage pulsed current (HVPC) [17-21], all of which have demonstrated evidence of decreased wound healing time by using ES.

A recent study by Houghton et al. indicates that ES can accelerate wound closure of chronic leg ulcers caused by diabetes and arterial and venous insufficiency [21]. Any acceleration of chronic ulcer closure would naturally result in economic savings and decreased amputation rates [23]. Thus, there is growing evidence to support ES in treating chronic wounds that have not responded to conventional treatment of wound debridement, cleansing, dressing, and infection treatment, including Antibiotics .

Four petri dishes (one set) plated with S. aureus were each stimulated with one of the following electrical stimulation types: (1) continuous µADC at 500 µA, (2) LVMmAPC at 30 mA and 128 pulses per second (pps), (3) LVBmAPC at 30 mA and 128 pps, and (4) HVPC at 250 V and 100 pps with an intraphase interval of 70 µs (Figure 3). Each ES type was applied to a corresponding set of four petri dishes for 1 h at 37 °C on consecutive days 1, 2, and 3. Following each ES treatment, the petri dishes were incubated for another 23 h at 37 °C, after which the diameter of the zone of inhibition (i.e., absence of bacterial growth) surrounding each electrode was measured to the nearest tenth of a millimeter by two investigators using calipers. Two separate measurements of each zone were taken by each investigator, one parallel and one perpendicular to the electrode. These measurements were then averaged to obtain a value for the zone of inhibition. Inter-tester reliability was determined using a 2 × 2 repeated measures analysis of variance (ANOVA). Each petri dish was also examined for electrode corrosion, gas formation, and media discoloration. A control set of four petri dishes, with bacteria but without ES, was incubated and measured as above. An additional control group of four petri dishes without bacteria underwent all procedures and was used to monitor the pH of each electrical stimulation type. Photographs were taken for reference purposes.

From: http://www.rehab.research.va.gov/jour/04/41/2/merriman.html