Enhancing host resistance to pressure ulcers: a new approach to prevention.

Pressure ulcers are notoriously common in spinal-cord-injured patients, in patients with other neurological deficits, in malnourished and severely debilitated patients, and in the frail elderly. Prolonged localized external pressure, coupled with insensitivity to ischemia resulting from neurologic injury, has long been considered the major causal factor. Preventive efforts have focused on the relief of pressure via frequent repositioning and the use of pressure-relieving devices. However, consensus is growing that host factors also play a role in the development of pressure ulcers, the most important in spinal-cord-injured patients being the injury-induced loss of vasomotor control below the level of the lesion, resulting in hypoxemia. Accordingly, pressure ulcers may be prevented not only by reducing external pressure but also by increasing the patient's resistance to pressure, that is, by directly influencing tissue oxygenation. Review of the literature suggests that electrical stimulation increases cutaneous blood flow and promotes the healing of pressure ulcers. Moreover, high-voltage pulsed galvanic stimulation (75 V, 10 Hz) applied to the back at spinal level T6 in spinal-cord-injured persons lying supine on egg-crate mattresses can raise sacral transcutaneous oxygen tension levels into the normal ranges (A. R. Mawson, F. H. Siddiqui, B. J. Connolly, C. J. Sharp, W. R. Summer, and J. J. Biundo, Jr., Paraplegia in press). Randomized controlled trials are needed to determine the efficacy of high-voltage pulsed galvanic stimulation for preventing pressure ulcers in spinal-cord-injured persons and other groups at high risk.