Effectiveness of local cooling for enhancing tissue ischemia tolerance in people with spinal cord injury.
When a patient lies in the supine position on a foam mattress, body heat is trapped and the sacral skin is rapidly warmed, potentially causing local perspiration that increases friction, shear, and maceration that may weaken skin in the area. Increased metabolic demand of the warmed skin tissue may exacerbate the supply-versus-demand perfusion deficit in tissue under mechanical load, increasing the severity of skin breakdown. Conversely, mild skin cooling appears to confer some protection. To estimate the magnitude of such effects, an integrative review using simple graphical techniques in conjunction with published data was initiated. Results suggest that a 5 degrees C reduction in skin temperature would have an effect similar to that of the differences in sacral interface pressure measured between some of the most and least expensive support surfaces available. Incorporating relatively simple skin cooling features might have profound implications with respect to therapeutic surface design, selection, and patient care. Further research is needed to determine whether and to what extent the observed increments in clinical performance seen for low-air-loss surfaces (beyond what is seen for quality foam surfaces) can be attributed to skin cooling and which are attributable to drying effects.