Text Size

Electrical stimulation of wound

Διεθνείς Δημοσιευσεις - ePlastry

Article Index
Electrical stimulation of wound
methology
discussion
conclusion
All Pages
Page 1 of 4
Eplasty. 2008; 8: e28.
Published online 2008 May 16.
PMCID: PMC2396465

 
Copyright © 2008 The Author(s)
Low-intensity Electrical Stimulation in Wound Healing: Review of the Efficacy of Externally Applied Currents Resembling the Current of Injury
Konstantine C. Balakatounis and Antonios G. Angoules
School of Health and Social Care, Oxford Brookes University, England, United Kingdom;
Filoktitis Medical Center (Center of Excellence in Physical Medicine and Rehabilitation), Athens, Greece; and
Academic Unit of Orthopaedic Surgery and Trauma, Leeds Teaching Hospitals, Leeds, England, United Kingdom
Correspondence: Email: This e-mail address is being protected from spambots. You need JavaScript enabled to view it
This is an open-access article whereby the authors retain copyright of the work. The article is distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
 
ABSTRACT
 
Objective: Low-intensity currents (LIC) have gained popularity during the last years, and nowadays the majority of electrotherapy units may produce LIC. On wounding, the body produces a current, the current of injury, which promotes healing. Still, this current may gradually decrease resulting occasionally to delayed or limited wound healing. Thus, by applying the same LIC externally, healing may be accelerated by sustaining the LIC throughout the healing phases. The first review of research studies on the effect of LIC on wound healing is attempted, which can be considered useful for the practicing clinician, to provide an overview of current evidence on the effectiveness of LIC and provide protocols of treatment. Methods: Comprehensive review of randomized-controlled trials investigating the effect of LIC on wound healing. Results: The review revealed that LIC promote wound healing and appear to be effective in the range of 200–800 μA. The direct current may be continuous or pulsed and polarity may or may not be reversed. Conclusion: Research available indicates that LIC accelerate wound healing. Further research is required to clarify the healing effects of LIC on wounds.
 
In 2002, electrical stimulation was approved in the United States, for Medicare coverage for the treatment of nonresponding to standard wound-healing strategies, pressure, diabetic, stasis, and arterial ulcers. The approval of electrical stimulation constitutes an indication of the growing acceptance and evidence for its application for wound healing.1
Electrical stimulation may be highly variable in form and parameters. There is a substantial number of research studies on wound healing,2 but there is rarely a differentiation among types of electrical current. Still, various forms of currents such as direct currents, pulsed direct currents, high- or low-voltage pulsed currents, alternative currents, and low-intensity currents (LIC) are available. Therefore, the identification of effective forms/parameters of currents, which are supported by randomized-controlled trials, may be considered as clinically relevant.
A review of the effectiveness of LIC on wound healing was considered important by the authors, because LIC resemble the currents produced by the human body on wounding; therefore, there is a reasonable question whether this particular form of currents may be a beneficial range of amplitude for wound healing despite the very low amplitude.
The purpose of the study was to concentrate available research on LIC stimulation for wound healing and conduct the first review on the specific topic, to investigate its effectiveness, guide clinicians by providing treatment protocols, and stimulate further research on LIC and wound healing.
 
DEFINITION AND TECHNICAL SPECIFICATIONS
 
Low-intensity electric currents or microcurrents (MCs) are currents of an intensity less than or equal to 1 mA (1000 μA, μA = microampere). The current may be direct or alternating of varying—mainly rectangular—waveforms, frequency, and pulse duration. Low-intensity currents were formerly known as MC electrical neuromuscular stimulators, but were later named microcurrent electrical stimulator (MES) (MC electrical stimulator).2
Microcurrents are produced by low-voltage generators or combined electrotherapy units. Such generators or units can produce a range of waveforms, from monophasic to square or rectangular biphasic, with a range of frequencies from 0.3 to 50 Hz. Electrotherapeutic units of low voltage may produce currents of intensities up to a few milliamperes in which case sensory stimulation or muscular stimulation results. Pulse duration may also be modified from 1 to 500 milliseconds at low frequencies or may be preselected when pulsed current is utilized.2
 
CURRENT OF INJURY
 
In 1843, Dubois-Reymond reported a current of an intensity of 1-mA exiting human skin wounds. It was later confirmed that wounds create a surrounding electric field, the “current of injury,” which was found to be of an intensity less than 1 mA.3,4 The current of injury extends up to a radius of 2–3 mm around the wound, and the gradient gradually decreases from 140 mV/mm to 0 mV/mm.5,6 It also appears that the transportation of Na+ into the cell, through the cell membrane, maintains skin “battery” of a potential difference of 20 to 40 mV, the negative pole being outside the cell.
It has been supported that the current of injury can be maintained if a moist occlusive dressing is applied, but will gradually decrease if the wound is left open and unprotected.6,7 As the wound heals, the current of injury is also reduced.6
By considering that healing appears to be promoted through the use of occlusive dressings,8,9 which retain the current of injury within the wound environment, it can be and has been postulated10 that the current of injury plays a significant role in wound healing.11 Therefore, it can be claimed that LIC may resemble the natural electric field/current created following injury, thus enhancing a complex biological mechanism of wound healing.12 One of those mechanisms is galvanotaxis. Galvanotaxis can be defined as the directional migration of various types of cells,13,14 such as endothelial cells,15 and keratinocytes, thus enhancing reepitheliazation.16,17 The biological processes underlying galvanotaxis are under investigation, 1 proposed mechanism being lateral electrophoresis resulting in changes in the plasma membrane and possibly affecting protein redistribution.11
 
Prev - Next >>