September 9, 2008

WOUND HEALING WITH ULTRAHIGH FREQUENCY SOUND^©

Lyn Paul Taylor, A.A., B.A., M.A., R.P.T.

(Editing Assistant and Computer Consultant: Joanna Soon, B.S.)

Fairly recent, in vivo research has demonstrated that ultrahigh frequency sound (ultrasound) can be used to stimulate the production of granulation tissue (specifically in trophic ulcers) as well as collagen and acid soluble non-collagenous protein synthesis in scar tissue.  It can increase the growth rate of replacement tissue at the site of injury and increase the rate of protein synthesis in fibroblasts.  Indeed, it has been shown that the rate of DNA synthesis in regenerating tissue is accelerated by exposure to ultrasound.  Clinically (by way of confirmation), ultrasound has been shown to be of immense value for the facilitation of the scar tissue formation required for complete wound healing and final closure, especially when applied to healing resistant surgical incisions or pressure sores (decubiti).

The mechanisms at work that promote synthesis of scar tissue when exposed to adequate levels of ultrasound are still only postulated, but it is thought that the nonthermal effects of ultrasound may be responsible for the facilitation of the required protein synthesis.

Application:

• To facilitate scar tissue formation, and retard or eradicate bacterial infection, the wound should be coated with a suitable coupling agent (di-alpha tocopheryl oil or topical ibuprofen may be preferable to colloidal gels) before ultrasound is applied.

• The ultrasound unit should be preset to deliver a 1 Mhz or 3 Mhz, pulsed waveform, at between 0.8 and 1.8 W/cm², for six to eight minutes (assuming the treatment area to be 72 cm² or less).

• Treatment should occur once or twice daily (there should be at least a 30-minute rest between applications), until the wound has closed and no underlying infection is evident.

It has been found that using di-alpha tocopheryl (vitamin E) oil as a coupling agent increases the effectiveness of ultrasound for the facilitation of the healing process.  Di-alpha tocopheryl has the effect of slowing down the healing process to allow for better granulation and of facilitating orderly collagen (scar tissue) formation.  The collagen tends to lay down in parallel fashion rather than at random, making for smaller, more elastic scars.  It also seems to reduce the tendency to produce keloid formations in keloid prone patients (those keloids which do develop are less pronounced and far less rigid).

Precautions:

Thrombus formations (blood clots) should not be ultra sounded because of the danger of increasing further thrombus formation or promoting emboli production.

Caution should be exercised when applying ultrasound to areas which suffer from inadequate circulation.  Such tissues may be threatened by elevated tissue temperatures, since the heat transfer normally provided by the circulatory system is missing.  In such cases, the continuous waveform of ultrasound should be avoided and only the pulsed waveform used.

Caution should also be exercised in the selection of active ingredients to be phonophoresed.  The practitioner should be concerned with the side effects that may result from exposure to medical preparations containing any steroid (cortisone or cortisol), especially in excess.  Besides the bad systemic side effects that may occur from corticosteroid treatment, phonophoresis of corticosteroids has been noted (in humans) to cause a transient increase in pain in some subjects (reportedly occurring in 10.6% of the cases seen).  Such pain may begin eight to 12 hours after application and last for two to 12 hours after onset.  After the pain subsided, the majority of patients were judged to have improved. This response is similar to the phenomenon noted as an infrequent secondary effect of corticosteroid percutaneous injection.

Any of the salicylates or ibuprofen may be of concern if the particular patient suffers from renal insufficiency (salicylates and ibuprofen must be excreted through the kidneys to be eliminated from the human system).  Such a prohibition should continue until research has established that the phonophoresis of salicylates or ibuprofen is harmless for a patient suffering from renal insufficiency or is prone to renal failure.

[For further precautions see ULTRAHIGH FREQUENCY SOUND, Precautions]

References:

M. Dyson, J.B. Pond, J. Joseph, and R. Warwick, "Stimulation of Tissue Regeneration by Pulsed Plane-Wave Ultrasound", IEEE Transactions on Sonics and Ultrasonics, July 1970. Pp. 133-139

M. Dyson and J. Suckling, "Stimulation of Tissue repair by Ultrasound: a Survey of the Mechanisms Involved", Physiotherapy, 64:4, 1978. Pp. 105-108

H.P. Ehrlich, H. Tarver, T.K. Hunt, "Inhibitory Effects of Vitamin E on Collagen Synthesis and Wound Repair", Annuls of Surgery, February 1972. Pp. 235-240

J.E. Griffin, "Physiological Effects of Ultrasonic Energy as It is Used Clinically", Journal of the American Physical Therapy Association, vol. 46, 1966. Pp. 18-26

F.E. Miller and J.B. Weaver, "Ultrasound Therapy", Physical Therapy Review, 34:11, 1954. p. 562

E.M. Oakley, "Application of Continuous Beam Ultrasound at Therapeutic Levels", Physiotherapy, 64:6, June 1978. Pp. 169-172

H.P. Schwan and E.L. Carstensen, "Advantages and Limitations of Ultrasonics in Medicine", JAMA, vol. 149, May 1952. Pp. 121-125

L.P. Taylor, T. Hui, The Taylor Technique of Soft Tissue Management, Inflammation: Evaluation & Treatment, 2002.  Pp. 57-59

Therapeutic Ultrasound, Reprinted from Physiotherapy, March/April, 1987, Journal of the Chartered Society of Physiotherapy, London, England.

F.S. Zach, B. Boynton, K. Phillips, and E. Smith, "Localized Application of Ultrasonic Energy", British Journal of Physical Medicine, August 1957.

M.C. Ziskin and S.L. Michlovitz, "Therapeutic Ultrasound", Thermal Agents in Rehabilitation, F.A. Davis Co., Philadelphia, Pa., 1986. Pp. 141-157

[Back to Articles]