Procedure

As mentioned in the previous blog, the standard therapeutic application, dosage and procedure is still not fully established. This blog is aiming to provide with the procedures and equipment used in current research that has shown successful application of microcurrent therapy in wound healing.

In terms of the application of microcurrent stimulation to wounds, the easiest application technique was using two metal electrodes with a spherical tip (10mm) positioned on the wound (de et al., 2011). Some would apply two layers of electrodes with tap water as the conducting medium (Lee, Wendell, Al-Waili, & Butler, 2007). Most were applied by using moistened silver nylon fabric shown in figure 1, as the surface of these fabrics can be tested with  a voltmeter to check for an even spread of current to the wound site (Becker & Spadaro, 1978; Huckfeldt, Flick, Mikkelson, Lowe, & Finley, 2007; Webster, Spadaro, Becker, & Kramer, 1981). Furthermore, alternative techniques such as electroacupunture also use low-frequency microcurrent, with stimulation conducted through acupuncture needles shown in figure 2, which also shows suppressed myostatin expression, and proliferative retention of skin tissues and repaired skeletal muscle (Takaoka et al., 2007).

Figure 1: Silver nylon favbric dressing. (Wound contact dressings, retrieved March 27, 2012)

Figure 2: Electroacupuncture, microcurrents stimulates through acupuncrure needles. (Electroacupuncture, rertrieved March 27, 2012)

Dosage can be separated into applied current, frequency and duration. As for current (microcurrent precisely), most of electrical stimulation employs current intensities between 1 and 999uA (Lee, et al., 2007). The voltage and current levels were significantly below the threshold of sensation of the patient (Huckfeldt, et al., 2007). The earliest application of electrical stimulation used 50-300uA direct current applied to silver nylon in 1983 keratome-induced wounds on pigs. This study found a significant increase in wound epithelialization. The lowest microcurrent used that has shown an effect on wound healing was at 20uA which induces the flow of electrons into the skin and subcutaneous injury (Fleischli & Laughlin, 1997). However, recent research in 2011 used 10uA/ 2min, and showed a positive effect on the number of fibroblasts, vascularization and epithelialization (de, et al., 2011). Microcurrent treatment, at an output of 100uA, the result shows effective reduced post exercise creatine kinase levels after induction of muscle damage (Fleischli & Laughlin, 1997). In addition, the results showed enhanced soft tissue healing and treatment of fracture nonunion (Bach, Bilgrav, Gottrup, & Jorgensen, 1991; Carley & Wainapel, 1985). However, the most commonly used microcurrent intensity was 40uA, and has proven to accelerate the wound healing process in 1988, 1990, 1991, 1993, 1994 and 1996 (Chu, Matylevich, McManus, Mason, & Pruitt, 1996; Chu, McManus, Mason, Okerberg, & Pruitt, 1990; Chu, McManus, Okerberg, Mason, & Pruitt, 1991). But a recent study indicates that the current should vary between 40 to 100uA dependent upon the resistance of the wounded skin site (Huckfeldt, et al., 2007).

Most frequencies applied to wound healing were all very low, normally ranging from sub1 to 150Hz, with the lowest one using ultra-low microcurrent at 0.000732Hz (Lee, et al., 2007).  Most of the other applications use around 0.5Hz (Santos et al., 2004).

The frequency and duration of microcurrent therapy application on wounds varies greatly. Early human clinical trials using microcurrent was reported in the early 80's using a standardized clinical technique in open wounds. Initial treatments were limited to 4 hour periods twice a day, but later expanded to all durations and frequency, even 24hrs continuous treatment (Webster, et al., 1981).

In one technique tested on chronic resistant wounds, the patients were treated with a direct current of 1 polarity for 12min and then the opposite polarity for another 12min. These patients were treated approximately 3.5hr/day, 5 days a week (Lee, et al., 2007). Another study applied microcurrent stimulation  48 hours after the trichloracetic acid peeling in rats. Each treatment was applied for 20 minutes and every two days up to day 21 for comparison, with the results showing significant increase in number of fibroblasts, with compact eosinophitic collagen fibers (Santos et al., 2004). In the research of the effect of microcurrent on the surgically induced wound healing in rats, the treatments started 24 hours after surgical intervention and were continued daily for 10 days (de, et al., 2011).

All of the above applied methods, current, frequency and duration of microcurrent stimulation therapy were shown to be successful and provided a significant decrease in the time of wound healing. Although there is no gold standard for the procedure and dosage, most research that has shown successful results used moistened silver nylon fabric in direct contact over the wound surface, with microcurrent ranging from 20-100uA with low frequency below 1Hz, over at least 20minutes a day until a wound heals.

The following are examples of the devices used in the research articles mentioned earlier. Two portable microcurrent devices used in Frick & McCauley’s (2005) research, called Alpha-Stim 100 Microcurrent & Cranial Electrotherapy Stimulator (shown in figure 3) costing US $995.00 and Alpha-Stim PPM Microcurrent Stimulator costing US $595.00 (Electromedical Products International, Inc; Mineral Wells, TX; https://store.alpha-stim.com/SearchResults.asp?Cat=1) The company described these devices as “extremely comfortable, usually no sensation at all.” Another device used in Lee's (2007; 2010) research (figure 4) is called BondiHealth TENS System (EPRT Technologies-USA, Simi Valley, CA; http://www.eprttechnologies.com/content/view/35/52/) although no prices were displayed on their website. However, it is expected to cost over $1000 as the entrance level portable devices advised for sport recovery already cost AU $995 (EPRT Technologies-USA, Simi Valley, CA; http://www.bodicharger.com/). All of the above devices are available directly to the public, with tutorial classes teaching the users. The company’s brochure described the feeling of the device as “Most patients feel nothing, but sometimes a slight tingling sensation may be experienced”. Although the prices for these devices might be acceptable for hospital settings, it is quite expensive for individual patients to purchase and most likely will only used for around one month until the wound heals.

Figure 3: Alpha-Stim 100 Microcurrent & Cranial Electrotherapy Stimulator
(The Alpha-Stim 100, retrieved march 27, 2012) 

Figure 4: BondiHealth TENS System
(BodiHealth TENS System, retrieved march 27, 2012)

Bach, S., Bilgrav, K., Gottrup, F., & Jorgensen, T. E. (1991). The effect of electrical current on healing skin incision. An experimental study. Eur J Surg, 157(3), 171-174.

Becker, R. O., & Spadaro, J. A. (1978). Treatment of orthopaedic infections with electrically generated silver ions. A preliminary report. J Bone Joint Surg Am, 60(7), 871-881.

Carley, P. J., & Wainapel, S. F. (1985). Electrotherapy for acceleration of wound healing: low intensity direct current. Arch Phys Med Rehabil, 66(7), 443-446.

Chu, C. S., Matylevich, N. P., McManus, A. T., Mason, A. D., Jr., & Pruitt, B. A., Jr. (1996). Direct current reduces wound edema after full-thickness burn injury in rats. J Trauma, 40(5), 738-742.

Chu, C. S., McManus, A. T., Mason, A. D., Jr., Okerberg, C. V., & Pruitt, B. A., Jr. (1990). Multiple graft harvestings from deep partial-thickness scald wounds healed under the influence of weak direct current. J Trauma, 30(8), 1044-1049; discussion 1049-1050.

Chu, C. S., McManus, A. T., Okerberg, C. V., Mason, A. D., Jr., & Pruitt, B. A., Jr. (1991). Weak direct current accelerates split-thickness graft healing on tangentially excised second-degree burns. J Burn Care Rehabil, 12(4), 285-293.

de, G. d. G. F. O., Foglio, M. A., de Carvalho, J. E., Santos, G. M., Testa, M., Passarini, J. R., Jr., . . . Mendonca, F. A. (2011). Effects of the Topical Application of Hydroalcoholic Leaf Extract of Oncidium flexuosum Sims. (Orchidaceae) and Microcurrent on the Healing of Wounds Surgically Induced in Wistar Rats. Evid Based Complement Alternat Med, 2011, 950347. doi: 10.1155/2011/950347
Electroacupuncture [Image] Retrieved March 27, 2012, from http://tweedacupuncture.com.au/electroacupuncture/

Fleischli, J. G., & Laughlin, T. J. (1997). Electrical stimulation in wound healing. J Foot Ankle Surg, 36(6), 457-461.

Frick, A. & McCauley, D. (2005), Microcurrent Electrical Therapy, Journal of Equine Veterinary Science 418 - 422

Huckfeldt, R., Flick, A. B., Mikkelson, D., Lowe, C., & Finley, P. J. (2007). Wound closure after split-thickness skin grafting is accelerated with the use of continuous direct anodal microcurrent applied to silver nylon wound contact dressings. J Burn Care Res, 28(5), 703-707. doi: 10.1097/BCR.0B013E318148C94501253092-200709000-00010

Lee, B. Y., Wendell, K., Al-Waili, N., & Butler, G. (2007). Ultra-low microcurrent therapy: a novel approach for treatment of chronic resistant wounds. Adv Ther, 24(6), 1202-1209. doi: 704 [pii]

Santos, V. N. S., Ferreira, L. M., Horibe, E. K., & Duarte, I. d. S. (2004). Electric microcurrent in the restoration of the skin undergon a trichloroacetic acid peeling in rats. Acta Cir Bra, 19 (5), 466-469.

Takaoka, Y., Ohta, M., Ito, A., Takamatsu, K., Sugano, A., Funakoshi, K., . . . Maeda, E. (2007). Electroacupuncture suppresses myostatin gene expression: cell proliferative reaction in mouse skeletal muscle. Physiol Genomics, 30(2), 102-110. doi: 00057.200610.1152/physiolgenomics.00057.2006

Webster, D. A., Spadaro, J. A., Becker, R. O., & Kramer, S. (1981). Silver anode treatment of chronic osteomyelitis. Clin Orthop Relat Res(161), 105-114.

Wound contact dressings [Image] Retrieved March 27, 2012 from  http://www.silverlon.com/consumer_otc_products.html