Electrical microcurrent stimulation therapy for wound healing: A meta-analysis of randomized clinical trials

https://doi.org/10.1016/j.jtv.2021.12.002Get rights and content

Highlights

  • First meta-analysis evaluating the effectiveness of external microcurrents devices.

  • Microcurrents are more effective than standard wound care alone.

  • Microcurrents are effective and safe in improving wound area, healing time, and pain.

  • Microcurrents can be equally effective as negative pressure wound therapy.

Abstract

Background

Electrical microcurrent therapy (EMT) consists of the application of low intensity (μA) currents that are similar to endogenous electric fields generated during wound healing.

Aims

To examine the effectiveness and safety of EMT for improving wound healing and pain in people with acute or chronic wounds.

Method

Randomized clinical trials (RCTs) assessing the effectiveness of EMT in wound healing published up to August 1st, 2020 were included. The main outcomes were wound surface area, healing time, and number of wounds healed. Secondary outcomes were pain perception and adverse events. A quantitative analysis was conducted using the inverse variance and Mantel-Haenszel methods.

Results

Eight RCTs were included in the qualitative summary and seven in the quantitative analysis (n = 337 participants). EMT plus standard wound care (SWC) produced a greater decrease in wound surface [mean difference (MD) = -8.3 cm2; CI 95%: −10.5 to −6.0] and healing time (MD = -7.0 days; CI 95%: −11.9 to −2.1) that SWC alone, showing moderate and low certainty in the evidence, respectively. However, no differences were observed in the number of healed wounds [risk ratio = 2.0; CI 95%: 0.5 to 9.1], with very low quality of evidence. EMT decreased perceived pain (MD = -1.4; CI 95%: −2.7 to −0.2), but no differences in adverse effects were noted between groups (risk difference = 0.05; CI 95%: −0.06 to 0.17).

Conclusions

EMT is an effective, safe treatment for improving wound area, healing time, and pain. Further clinical trials that include detailed intervention parameters and protocols should be designed to lower the risk of bias.

Introduction

For decades, electrical stimulation has been evaluated for improving wound healing and some clinical practice guidelines recommend their use for accelerating the healing process of wounds [[1], [2], [3]]. A recent systematic review and meta-analysis concluded that electrical stimulation increases the proportion of healed pressure ulcers and their rate of healing, with moderate certainty in the evidence [4]. One of the main limitations of these recommendations is that the included studies employed a great variety of application protocols and, especially, different types of electric currents [5]. Khouri et al. [6] assessed the effect size of various types of electric currents in the healing of chronic wounds and concluded that the effect of high voltage pulsed current was superior. However, this meta-analysis excluded trials that applied microcurrents for improving wound healing [6].

Compared to other methods of electrical stimulation, microcurrents present a key differentiating factor related to current intensity and therefore to the applied dose: it delivers microamps (μA) current intensities while other electrical stimulation methods apply current intensities of milliamps (mA). Of note, the endogenous electric fields generated during wound healing, which play an essential role in cell migration and the healing of epithelial wounds, are in the order of microcurrents (approximately 5 μA/cm2) [7]. Therefore, applying exogenous electric fields of the same magnitude as the endogenous currents generated during healing (μA) appears to be a more appropriate method. Along these lines, some preclinical studies have revealed the effect of applying exogenous microcurrents at a molecular level and on human dermal fibroblasts, which stimulate the proliferation and cell migration involved in the healing process [[8], [9], [10]]. In addition, traditionally employed currents deliver an intensity above the sensorial and/or motor thresholds, which sometimes are uncomfortable for the patient. In contrast, microcurrents do not reach the threshold for depolarization of nerve fibers and are imperceptible [5]. A recent systematic review without meta-analysis by Ofstead et al. [11] evaluated the effect of microcurrents on wound healing, but only included trials applying continuous electric stimulation during 24 h a day. Only four randomized clinical trials (RCTs) met the inclusion criteria, two of which used bioelectric dressings instead of an external device for generating microcurrents. To our knowledge, ours is the first meta-analysis that assesses the effectiveness of electric stimulation in wound healing using external devices to deliver microcurrents.

The main objective of this meta-analysis was to assess the effectiveness of electrical microcurrent therapy (EMT) plus standard wound care (SWC) for improving wound healing compared to SWC alone (control or sham control) or other conservative treatments. The secondary aims were to evaluate the effect of EMT on pain relief and the safety of this method for its application in patients with cutaneous wounds.

Section snippets

Methods

This meta-analysis followed the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) Statement [12] and the recommendations by The Cochrane Collaboration [13]. Its protocol was registered in PROSPERO (reference number CRD42020189870).

Study selection

Following removal of duplicates, 308 articles were identified as eligible, of which 270 were eliminated after reading the title and abstract. After reading the full text, eight RCTs were included [[17], [18], [19], [20], [21], [22], [23], [24]] in the qualitative synthesis. The study by Ullah et al. [24] was excluded from the pooled quantitative analysis because the variable measuring healing was expressed by the rate of change in the wound surface area and did not assess any of the secondary

Discussion

This meta-analysis assessed the effectiveness of EMT plus SWC on wound healing versus SWC alone or another conservative treatment as is NPWT. EMT plus SWC showed a greater reduction in the wound area (≈8 cm2) and shorter periods to complete healing (≈7 days) compared to that experienced by SWC alone, with moderate and low recommendation levels according to GRADE, respectively. Furthermore, a cost-effectiveness study with the lowest risk of bias included in this review showed that EMT achieved a

Conclusions

The current meta-analysis supports the conclusion that incorporating EMT to SWC of acute and chronic wounds improves healing by reducing the wound area and time to complete healing, with moderate and low certainty in the evidence, respectively. Additionally, EMT reduces pain perception and has proven to be a safe technique with few minor side effects. The effect on the healing time can be of special importance in chronic wounds or those with greater healing problems. The findings of this work

Funding support

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Declaration of competing interest

None.

References (31)

  • M. Zhao
    (2009)
  • G. Guyatt et al.

    GRADE guidelines: 1. Introduction—GRADE evidence profiles and summary of findings tables

    J Clin Epidemiol

    (2011 Apr)
  • K. Carville et al.

    The “Pan Pacific clinical practice guideline for the prevention and management of pressure injury

    Wound Pract Res J Aust Wound Manag Assoc.

    (2012)
  • P.E. Houghton et al.

    Canadian best practice guidelines for the prevention and management of pressure ulcers in people with spinal cord injury: a resource handbook for clinicians

    (2013)
  • A. Qaseem et al.

    Treatment of pressure ulcers: a clinical practice guideline from the American College of Physicians

    Ann Intern Med

    (2015)
  • M. Arora et al.

    Electrical stimulation for treating pressure ulcers

    Cochrane Database Syst Rev

    (2020 Jan 22)
  • P.E. Houghton

    Clinical trials involving biphasic pulsed current, MicroCurrent, and/or low-intensity direct current

    Adv Wound Care

    (2014)
  • C. Khouri et al.

    Hierarchical evaluation of electrical stimulation protocols for chronic wound healing: an effect size meta-analysis

    Wound Repair Regen

    (2017 Sep 1)
  • I. Todd et al.

    Electrical stimulation of transforming growth factor-β1 secretion by human dermal fibroblasts and the U937 human monocytic cell line

    Altern to Lab Anim

    (2001 Nov 9)
  • E. Konstantinou et al.

    Microcurrent stimulation triggers MAPK signaling and TGF-β1 release in fibroblast and osteoblast-like cell lines

    Cells

    (2020 Aug 19)
  • M. Sugimoto et al.

    Optimum microcurrent stimulation intensity for galvanotaxis in human fibroblasts

    J Wound Care

    (2012)
  • C.L. Ofstead et al.

    The impact of continuous electrical microcurrent on acute and hard-to-heal wounds: a systematic review [Internet]

    Jwound care

    (2020)
  • D. Moher et al.

    Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement

    BMJ

    (2009 Jul 21)
  • J.P.T. Higgins et al.

    Measuring inconsistency in meta-analyses

    BMJ

    (2003 Sep 6)
  • Cited by (8)

    View all citing articles on Scopus
    View full text