Electrotherapy and wound healing - Part 1

Introduction

Our business would not exist if it were not for pressure ulcers. I had seen a product in the Cleveland Clinic in Ohio and was inspired to work with it. So when Anatomical Concepts was founded we introduced the PRAFO (Pressure Relief Ankle Foot Orthosis) range to the UK and have used these products to prevent and treat heel ulcers ever since. They represent a very practical approach to managing the mechanical environment essential to avoid or treat pressure ulcers at the heel.

What’s a pressure ulcer? It’s basically any skin lesion, usually over a bony prominence, caused by unrelieved pressure resulting in damage of the underlying tissue. It’s estimated that over 400,000 individuals will develop a pressure ulcer each year in the UK with a total cost to the healthcare system estimated to be between £1.4 and £2.1 Billion. (Bennett, 2004) Pressure ulcers and wounds of various kinds are a frequent clinical problem that just wont go away.

Once known as pressure sores, bedsores, or decubitus ulcers these wounds are commonly seen in situations where persons are "at risk" due to their compromised medical status. As the name suggests, they are often associated with mechanical effects such as localised pressure and shear sufficient to cause ulceration when other risk factors are present.

Areas such as the heel, sacrum, elbows and shoulder blades are especially vulnerable and need protection.

We have written previously about dealing with the mechanical environment using the PRAFO designs as an example. See the following articles

How a PRAFO defeats heel pressure ulcers and Pressure ulcers at the heel in 2020

Who is at risk of pressure ulcers?

The list isn’t short

• Diabetic Foot Disease - with Neuropathy & Arterial Narrowing

• Any Chronic Condition Requiring Bed Rest

• Lower Limb Fractures and Multisystem Trauma

• Combinations of Immobility, Dehydration, Immunosuppression, Malnutrition

• Spinal Cord Injury

• Critical Care Situations - Immobility

• Significant Obesity or Thinness

• Degenerative Neurological Disease such as Dementia

• Cardiovascular compromise

• History of Previous Ulceration

• Compromised Nutritional Status

Of course, the best strategy would be to always take steps to prevent pressure ulcers but the fact is we see many arise with significant personal and societal cost as a result.

Treatment should deal with both the medical and mechanical risk factors. The PRAFO designs for example, aim to eliminate pressure and shear at the heel area. Without eliminating these no amount of “lotions and potions” will help.

My one time colleague Duncan Stang put it very well. “It’s not what you put on the wound that heals it - it’s what you take off - specifically pressure and shear”

Electrotherapy approach

Many different treatment strategies exist for the management of wounds and particularly those that become chronic; some treatment approaches are invasive, such as wound debridement and skin substitute application, whilst others are noninvasive, such as compression bandaging, wound dressings and of course pressure relief measures.

An approach that uses electrotherapy may be surprising to many. However, the body is essentially a bioelectric mechanism. The body naturally produces what we could call endogenous (inside the body), electrochemical signals in different areas such as the bones, skin, muscles, brain and heart.

We are also familiar with using electrotherapy in many different ways (applied exogenously) to deal with pain, build muscle or to allow paralysed limbs to be actively exercised. Many of our FES Cycling clients, for example, use a RehaMove system to keep their muscle tissue in good health. Using regular FES Cycling to stimulate the gluteal muscles can reduce the risk of pressure ulcers to the ischial tuberosity area.

Endogenous current

In 1843, Du Bois-Reymond first measured a natural electric current of 1 𝜇A flowing out of a cut on his finger. We now know that the human epidermis actually exhibits a natural skin “battery”. In physiological solution there are no free electrons to carry current but unbroken skin layers of the epidermis and dermis maintain this skin battery through ionic movement.

Things change significantly when the skin is broken. Broken skin generates a small electric current when wounded. Healing is arrested when the flow of current is disturbed or when the current flow is stopped during prolonged opening of the skin.

In wound healing with electrotherapy four main approaches have been tried. Sometimes it can be confusing due to inconsistent terminology in the literature but these approaches are basically as follows

• Direct Current - basically an applied current that does not change over time

• Alternating Current - a pattern that changes smoothly and is both alternatively positive and then negative (like a sine wave)

• Pulsed Current - regular, repeating pulses; perhaps only positive or negative or bipolar

• Transcutaneous Electrical Nerve Stimulation - is in effect a pulsed form with an energy form sufficient to activate the local nerves.

The wound healing process is complex with a multitude of biomolecular pathways, but comprises four distinct yet interrelated phases: hemostasis, inflammation, proliferation, and remodeling. The mechanisms by which cells sense and respond to electrotherapy are relatively unclear. We do believe though that by using electrotherapy it is possible to influence the electrical activity of the cell membrane and induce specific cellular responses.

In the next article in this series-

We will examine the apparent pros and cons of the various electrotherapy modes, look at the contraindications and some protocols we have used that rely on the RehaMove stimulator from Hasomed and the Edition 5 or RISE stimulators.

References

Bennett, G et al (2004) "The cost of pressure ulcers in the UK" in Age and Ageing 2004, Vol 33: No.3, 230-235