Electrical microcurrent stimulation therapy for wound healing: A meta-analysis of randomized clinical trials
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)
- (2009)
- et al.
GRADE guidelines: 1. Introduction—GRADE evidence profiles and summary of findings tables
J Clin Epidemiol
(2011 Apr) - 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) - 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) - et al.
Treatment of pressure ulcers: a clinical practice guideline from the American College of Physicians
Ann Intern Med
(2015) - et al.
Electrical stimulation for treating pressure ulcers
Cochrane Database Syst Rev
(2020 Jan 22) Clinical trials involving biphasic pulsed current, MicroCurrent, and/or low-intensity direct current
Adv Wound Care
(2014)- et al.
Hierarchical evaluation of electrical stimulation protocols for chronic wound healing: an effect size meta-analysis
Wound Repair Regen
(2017 Sep 1) - 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) - et al.
Microcurrent stimulation triggers MAPK signaling and TGF-β1 release in fibroblast and osteoblast-like cell lines
Cells
(2020 Aug 19)
Optimum microcurrent stimulation intensity for galvanotaxis in human fibroblasts
J Wound Care
The impact of continuous electrical microcurrent on acute and hard-to-heal wounds: a systematic review [Internet]
Jwound care
Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement
BMJ
Measuring inconsistency in meta-analyses
BMJ
Cited by (8)
Biomaterials releasing drug responsively to promote wound healing via regulation of pathological microenvironment
2023, Advanced Drug Delivery ReviewsSerum lipidomics-based study of electroacupuncture for skin wound repair in rats
2023, Journal of Cellular and Molecular MedicineElectroacupuncture promotes skin wound repair by improving lipid metabolism and inhibiting ferroptosis
2023, Journal of Cellular and Molecular Medicine