Physical modalities is a broad umbrella term that encompasses a variety of treatment options practitioners may use to manage their patients with wounds. These modalities are based in physical energy, which is nothing new in medicine: The use of physical energy to treat maladies in both body and mind can be traced to antiquity. In the more recent past, physical energy has been used for diagnostic purposes, such as X-ray and magnetic resonance imaging.
In the conceptual framework for applying external physical energy to the human body, energy is harnessed and delivered by a focused, safe method to evoke a response in the target tissues. The applied energy may be diagnostic (eg, ultrasound), constructive (eg, healing), or destructive, depending on the intent and the targeted body structure. For example, therapeutic radiation used in a patient with cancer may harm the patient's skin while it destroys a tumor and possibly saves the patient's life.
Examining the Options
Judging by the papers the journal has received, the sessions we are planning for the upcoming Clinical Symposium on Advances in Skin & Wound Care, and the questions we are asked, skin and wound care practitioners definitely have a renewed interest in physical modalities as a means of healing their patients' chronic wounds. Currently available physical modalities deliver focused energy to the skin and the subjacent tissues. These modalities include:
* electrical stimulation- delivers direct or alternating electrical current to the wound, using microstimulators packaged in various configurations and various delivery microelectrodes (surface or implantable)
* pulsed magnetic therapy- used to enhance bone formation and connective tissue regeneration, chronic wound tissue regeneration, and nerve tissue regeneration, all reportedly without adverse effects
* systemic hyperbaric oxygen- oxygen applied at pressure greater than 1 atmosphere (1 atmosphere is ambient pressure at sea level [760 mm Hg or 14.7 psi]); administered in a full body chamber with the patient breathing 100% oxygen intermittently as the pressure of the treatment chamber is increased to 2 to 3 atmospheres (equivalent to 1500 to 2500 mm Hg or 30-45 psi).
* topical oxygen- oxygen applied directly to the base of an open wound at pressure slightly above atmospheric, eg, 1.03 atmospheres (22 mm Hg or 0.4 psi)
* negative pressure wound therapy- designed to enhance tissue migration and wound closure through the use of subatmospheric (negative) pressure
* light-emitting diodes- utilize near infrared light to provide energy in the form of red light
* diathermy- uses high-frequency current to generate heat in body tissues and facilitate repair
* iontophoresis- based on the electrical principle that like charges repel and unlike charges attract; used to drive electrically charged medications into subjacent tissue
* phonophoresis- uses sound waves to move the therapeutic agent into the skin.
The Jury Is Out-for Now
Not all of these physical modalities have strength-of-evidence ratings to support their generalized use in wound care-yet. Scientific data from randomized, prospective clinical trials are beginning to emerge and to be accepted by both practitioners and payers.
Although the verdict is not yet in, we presume that most of these modalities assist wound healing by enhancing the local wound environment. For example, they do so by increasing:
* oxygenation
* blood flow
* chemotaxisis of white blood cells
* activity of the fibroblasts
* wound contraction
* epidermal migration
* tensile strength
* edema reduction
* nitric oxide production
* mechanical pressure, which enhances wound closure.
In my view, these physical modalities are best used in combination with standard wound care, such as debridement, offloading, and appropriate moist wound dressings as indicated for the patient's wound. As wound care practitioners, we should be prepared to embrace the latest technology that brings physical modalities to the bedside and uphold established principles of wound care.