Ultrasound/Ultraviolet C
Houghton and Campbell (2007) note that both ultrasound (US) and ultraviolet light C (UVC) have been used in the treatment of chronic wounds. Ultrasound acts mainly at the “inflammatory stage of the wound healing cascade to stimulate the release of chemical mediators of cells which in turn produces changes in the amount and strength or integrity of the scar tissue” (Houghton et al. 2001; p 464). The bactericidal effects of UVC suggest that it is indicated for the treatment of chronic infected wounds where there is much surface bacteria or where bacteria have become resistant to antibiotic therapy. As well, research supports the use of UVC in the treatment of chronic infected wounds, while therapeutic US was not shown to have added benefit when used to treat pressure injuries. The Consortium of Spinal Cord Medicine (2000) and Houghton et al. (2013) found minimal data specific to the use of US or UVC to treat pressure injuries in SCI. Schmuckler (2008) in a case series of 5 SCI patients with sacral pressure injuries used low frequency, noncontact, nonthermal ultrasound (Acoustic Pressure Wound Therapy, MIST Therapy Systems) to prepare the wound bed for subsequent treatments. The author demonstrated that in 80% of wounds the therapy was effective in reducing slough and eschar (e.g., shedding dead tissue), promoting granulation tissue and reducing wound area and volume. One small RCT will be discussed that combined US/UVC and compared its effects to laser and standard wound care.
Discussion
In one small RCT (n=16) Nussbaum et al. (1994) demonstrated that between standard wound care with or without US/UVC, the combined treatment showed a greater effect on wound healing in a shorter period of time. Since US and UVC alternated over 5 days was considered a single treatment, efficacy conclusions do not cover the individual effects of US or UVC. Understanding the effects of US or UVC individually or in different combinations would require further study.
Conclusion
There is level 1b evidence (from one randomized controlled trial: Nussbaum et al. 1994) that the combination of US/UVC with standard wound care decreases wound healing time of pressure injuries post SCI; there is no evidence to support the benefit of UVC or US, used individually.
