Effect of high voltage pulsed galvanic stimulation on sacral transcutaneous oxygen tension levels in the spinal cord injured.

Evidence is mounting that spinal cord injured (SCI) persons may be at increased risk of pressure ulcers due to prolonged immobilization together with the injury-induced loss of sympathetic tone and decreased vascular resistance. With a view to developing a new method of preventing pressure ulcers, the objective of this study was to determine whether high voltage pulsed galvanic stimulation (HVPGS) could increase sacral transcutaneous oxygen tension (PtcO2) in SCI persons lying prone and supine. In experiment 1, HVPGS applied to the back at spinal level T6 led to a sustained, dose-related increase in sacral PtcO2 in 3 subjects lying prone. In experiment 2, carried out on 29 subjects lying supine on egg-crate mattresses, HVPGS (75 volts, 10 Hz) produced a 35% increase in sacral PtcO2, from a baseline level (Mean +/- SD) of 49 +/- 21 mmHg to 66 +/- 18 mmHg after 30 minutes of stimulation (F = 39.4, p < .00001). In experiment 3, simulated HVPGS was found to have no effect on sacral PtcO2 in 5 subjects lying supine. In experiment 4, HVPGS was repeated on 10 subjects and its effects found to be highly reproducible. It is hypothesized that HVPGS restores sympathetic tone and vascular resistance below the level of the spinal cord lesion, thereby increasing the perfusion pressure gradient in the capillary beds. Randomized controlled trials are now indicated to determine the efficacy of HVPGS for preventing pressure ulcers.